86 results on '"Chen GK"'
Search Results
2. A meta-analysis identifies new loci associated with body mass index in individuals of African ancestry
- Author
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Wiencke, John, Witte, John, Wrensch, Margaret, Monda, KL, Chen, GK, Taylor, KC, Palmer, C, Edwards, TL, Lange, LA, Ng, MCY, Adeyemo, AA, Allison, MA, and Bielak, LF
- Abstract
Genome-wide association studies (GWAS) have identified 36 loci associated with body mass index (BMI), predominantly in populations of European ancestry. We conducted a meta-analysis to examine the association of >3.2 million SNPs with BMI in 39,144 men and
- Published
- 2013
3. Population Genetic Structure and Origins of Native Hawaiians in the Multiethnic Cohort Study
- Author
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Wall, Jeffrey, Kim, SK, Gignoux, CR, Wall, JD, Lum-Jones, A, Wang, H, Haiman, CA, Chen, GK, Henderson, BE, Kolonel, LN, and Le, L
- Abstract
The population genetic structure of Native Hawaiians has yet to be comprehensively studied, and the ancestral origins of Polynesians remain in question. In this study, we utilized high-resolution genome-wide SNP data and mitochondrial genomes of 148 and 16
- Published
- 2012
4. Genome-wide meta-analyses of smoking behaviors in African Americans.
- Author
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David, SP, Hamidovic, A, Chen, GK, Bergen, AW, Wessel, J, Kasberger, JL, Brown, WM, Petruzella, S, Thacker, EL, Kim, Y, Nalls, MA, Tranah, GJ, Sung, YJ, Ambrosone, CB, Arnett, D, Bandera, EV, Becker, DM, Becker, L, Berndt, SI, Bernstein, L, Blot, WJ, Broeckel, U, Buxbaum, SG, Caporaso, N, Casey, G, Chanock, SJ, Deming, SL, Diver, WR, Eaton, CB, Evans, DS, Evans, MK, Fornage, M, Franceschini, N, Harris, TB, Henderson, BE, Hernandez, DG, Hitsman, B, Hu, JJ, Hunt, SC, Ingles, SA, John, EM, Kittles, R, Kolb, S, Kolonel, LN, Le Marchand, L, Liu, Y, Lohman, KK, McKnight, B, Millikan, RC, Murphy, A, Neslund-Dudas, C, Nyante, S, Press, M, Psaty, BM, Rao, DC, Redline, S, Rodriguez-Gil, JL, Rybicki, BA, Signorello, LB, Singleton, AB, Smoller, J, Snively, B, Spring, B, Stanford, JL, Strom, SS, Swan, GE, Taylor, KD, Thun, MJ, Wilson, AF, Witte, JS, Yamamura, Y, Yanek, LR, Yu, K, Zheng, W, Ziegler, RG, Zonderman, AB, Jorgenson, E, Haiman, CA, and Furberg, H
- Subjects
Chromosomes ,Human ,Pair 10 ,Chromosomes ,Human ,Pair 15 ,Humans ,Genetic Predisposition to Disease ,Proteoglycans ,Receptors ,Nicotinic ,Nerve Tissue Proteins ,Smoking ,Genotype ,Phenotype ,Polymorphism ,Single Nucleotide ,Adult ,Aged ,Middle Aged ,African Americans ,Female ,Male ,Statistics as Topic ,Genetic Variation ,Genome-Wide Association Study ,Genetic Loci ,African American ,genome-wide association ,health disparities ,nicotine ,smoking ,tobacco ,Chromosomes ,Human ,Pair 10 ,Pair 15 ,Polymorphism ,Single Nucleotide ,Receptors ,Nicotinic ,Clinical Sciences ,Public Health and Health Services ,Psychology - Abstract
The identification and exploration of genetic loci that influence smoking behaviors have been conducted primarily in populations of the European ancestry. Here we report results of the first genome-wide association study meta-analysis of smoking behavior in African Americans in the Study of Tobacco in Minority Populations Genetics Consortium (n = 32,389). We identified one non-coding single-nucleotide polymorphism (SNP; rs2036527[A]) on chromosome 15q25.1 associated with smoking quantity (cigarettes per day), which exceeded genome-wide significance (β = 0.040, s.e. = 0.007, P = 1.84 × 10(-8)). This variant is present in the 5'-distal enhancer region of the CHRNA5 gene and defines the primary index signal reported in studies of the European ancestry. No other SNP reached genome-wide significance for smoking initiation (SI, ever vs never smoking), age of SI, or smoking cessation (SC, former vs current smoking). Informative associations that approached genome-wide significance included three modestly correlated variants, at 15q25.1 within PSMA4, CHRNA5 and CHRNA3 for smoking quantity, which are associated with a second signal previously reported in studies in European ancestry populations, and a signal represented by three SNPs in the SPOCK2 gene on chr10q22.1. The association at 15q25.1 confirms this region as an important susceptibility locus for smoking quantity in men and women of African ancestry. Larger studies will be needed to validate the suggestive loci that did not reach genome-wide significance and further elucidate the contribution of genetic variation to disparities in cigarette consumption, SC and smoking-attributable disease between African Americans and European Americans.
- Published
- 2012
5. Admixture mapping identifies a locus on 6q25 associated with breast cancer risk in US Latinas
- Author
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Fejerman L, Chen GK, Eng C, Huntsman S, Hu D, Williams A, Pasaniuc B, John EM, Via M, Gignoux C, Ingles S, Monroe KR, Kolonel LN, Torres-Mejía G, Pérez-Stable EJ, Burchard EG, Henderson BE, Haiman CA, and Ziv E
- Abstract
Among US Latinas and Mexican women, those with higher European ancestry have increased risk of breast cancer. We combined an admixture mapping and genome-wide association mapping approach to search for genomic regions that may explain this observation. Latina women with breast cancer (n= 1497) and Latina controls (n= 1272) were genotyped using Affymetrix and Illumina arrays. We inferred locus-specific genetic ancestry and compared the ancestry between cases and controls. We also performed single nucleotide polymorphism (SNP) association analyses in regions of interest. Correction for multiple-hypothesis testing was conducted using permutations (P(corrected)). We identified one region where genetic ancestry was significantly associated with breast cancer risk: 6q25 [odds ratio (OR) per Indigenous American chromosome 0.75, 95% confidence interval (CI): 0.65-0.85, P= 1.1 × 10(-5), P(corrected)= 0.02]. A second region on 11p15 showed a trend towards association (OR per Indigenous American chromosome 0.77, 95% CI: 0.68-0.87, P= 4.3 × 10(-5), P(corrected)= 0.08). In both regions, breast cancer risk decreased with higher Indigenous American ancestry in concordance with observations made on global ancestry. The peak of the 6q25 signal includes the estrogen receptor 1 (ESR1) gene and 5' region, a locus previously implicated in breast cancer. Genome-wide association analysis found that a multi-SNP model explained the admixture signal in both regions. Our results confirm that the association between genetic ancestry and breast cancer risk in US Latinas is partly due to genetic differences between populations of European and Indigenous Americans origin. Fine-mapping within the 6q25 and possibly the 11p15 loci will lead to the discovery of the biologically functional variant/s behind this association.
- Published
- 2012
6. A common variant at the TERT-CLPTM1L locus is associated with estrogen receptor-negative breast cancer
- Author
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Haiman, CA, Chen, GK, Vachon, CM, Canzian, F, Dunning, A, Millikan, RC, Wang, X, Ademuyiwa, F, Ahmed, S, Ambrosone, CB, Baglietto, L, Balleine, R, Bandera, EV, Beckmann, MW, Berg, CD, Bernstein, L, Blomqvist, C, Blot, WJ, Brauch, H, Buring, JE, Carey, LA, Carpenter, JE, Chang-Claude, J, Chanock, SJ, Chasman, DI, Clarke, CL, Cox, A, Cross, SS, Deming, SL, Diasio, RB, Dimopoulos, AM, Driver, WR, Duennebier, T, Durcan, L, Eccles, D, Edlund, CK, Ekici, AB, Fasching, PA, Feigelson, HS, Flesch-Janys, D, Fostira, F, Foersti, A, Fountzilas, G, Gerty, SM, Giles, GG, Godwin, AK, Goodfellow, P, Graham, N, Greco, D, Hamann, U, Hankinson, SE, Hartmann, A, Hein, R, Heinz, J, Holbrook, A, Hoover, RN, Hu, JJ, Hunter, DJ, Ingles, SA, Irwanto, A, Ivanovich, J, John, EM, Johnson, N, Jukkola-Vuorinen, A, Kaaks, R, Ko, Y-D, Kolonel, LN, Konstantopoulou, I, Kosma, V-M, Kulkarni, S, Lambrechts, D, Lee, AM, Le Marchand, L, Lesnick, T, Liu, J, Lindstrom, S, Mannermaa, A, Margolin, S, Martin, NG, Miron, P, Montgomery, GW, Nevanlinna, H, Nickels, S, Nyante, S, Olswold, C, Palmer, J, Pathak, H, Pectasides, D, Perou, CM, Peto, J, Pharoah, PDP, Pooler, LC, Press, MF, Pylkas, K, Rebbeck, TR, Rodriguez-Gil, JL, Rosenberg, L, Ross, E, Ruediger, T, Silva, IDS, Sawyer, E, Schmidt, MK, Schulz-Wendtland, R, Schumacher, F, Severi, G, Sheng, X, Signorello, LB, Sinn, H-P, Stevens, KN, Southey, MC, Tapper, WJ, Tomlinson, I, Hogervorst, FBL, Wauters, E, Weaver, J, Wildiers, H, Winqvist, R, Van Den Berg, D, Wan, P, Xia, LY, Yannoukakos, D, Zheng, W, Ziegler, RG, Siddiq, A, Slager, SL, Stram, DO, Easton, D, Kraft, P, Henderson, BE, Couch, FJ, and Gene, EIBC
- Abstract
Estrogen receptor (ER)-negative breast cancer shows a higher incidence in women of African ancestry compared to women of European ancestry. In search of common risk alleles for ER-negative breast cancer, we combined genome-wide association study (GWAS) data from women of African ancestry (1,004 ER-negative cases and 2,745 controls) and European ancestry (1,718 ER-negative cases and 3,670 controls), with replication testing conducted in an additional 2,292 ER-negative cases and 16,901 controls of European ancestry. We identified a common risk variant for ER-negative breast cancer at the TERT-CLPTM1L locus on chromosome 5p15 (rs10069690: per-allele odds ratio (OR) = 1.18 per allele, P = 1.0 × 10−10). The variant was also significantly associated with triple-negative (ER-negative, progesterone receptor (PR)-negative and human epidermal growth factor-2 (HER2)-negative) breast cancer (OR = 1.25, P = 1.1 × 10−9), particularly in younger women (
- Published
- 2011
7. The landscape of recombination in African Americans
- Author
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Hinch, AG, Tandon, A, Patterson, N, Song, Y, Rohland, N, Palmer, CD, Chen, GK, Wang, K, Buxbaum, SG, Akylbekova, EL, Aldrich, MC, Ambrosone, CB, Amos, C, Bandera, EV, Berndt, SI, Bernstein, L, Blot, WJ, Bock, CH, Boerwinkle, E, Cai, Q, Caporaso, N, Casey, G, Adrienne Cupples, L, Deming, SL, Ryan Diver, W, Divers, J, Fornage, M, Gillanders, EM, Glessner, J, Harris, CC, Hu, JJ, Ingles, SA, Isaacs, W, John, EM, Linda Kao, WH, Keating, B, Kittles, RA, Kolonel, LN, Larkin, E, Le Marchand, L, McNeill, LH, Millikan, RC, Musani, S, Neslund-Dudas, C, Nyante, S, Papanicolaou, GJ, Press, MF, Psaty, BM, Reiner, AP, Rich, SS, Rodriguez-Gil, JL, Rotter, JI, Rybicki, BA, Schwartz, AG, Signorello, LB, Spitz, M, Strom, SS, Thun, MJ, Tucker, MA, Wang, Z, Wiencke, JK, Witte, JS, Wrensch, M, Wu, X, Yamamura, Y, Zanetti, KA, Zheng, W, Ziegler, RG, Zhu, X, Redline, S, Hirschhorn, JN, Henderson, BE, Taylor Jr, HA, Price, AL, Hakonarson, H, Chanock, SJ, Haiman, CA, Wilson, JG, Reich, D, and Myers, SR
- Published
- 2011
8. Meta-analysis identifies common variants associated with body mass index in east Asians
- Author
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Wen, W, Cho, Y-S, Zheng, W, Dorajoo, R, Kato, N, Qi, L, Chen, C-H, Delahanty, RJ, Okada, Y, Tabara, Y, Gu, D, Zhu, D, Haiman, CA, Mo, Z, Gao, Y-T, Saw, S-M, Go, M-J, Takeuchi, F, Chang, L-C, Kokubo, Y, Liang, J, Hao, M, Le Marchand, L, Zhang, Y, Hu, Y, Wong, T-Y, Long, J, Han, B-G, Kubo, M, Yamamoto, K, Su, M-H, Miki, T, Henderson, BE, Song, H, Tan, A, He, J, Ng, DP-K, Cai, Q, Tsunoda, T, Tsai, F-J, Iwai, N, Chen, GK, Shi, J, Xu, J, Sim, X, Xiang, Y-B, Maeda, S, Ong, RTH, Li, C, Nakamura, Y, Aung, T, Kamatani, N, Liu, J-J, Lu, W, Yokota, M, Seielstad, M, Fann, CSJ, Wu, J-Y, Lee, J-Y, Hu, FB, Tanaka, T, Tai, ES, Shu, X-O, Wen, W, Cho, Y-S, Zheng, W, Dorajoo, R, Kato, N, Qi, L, Chen, C-H, Delahanty, RJ, Okada, Y, Tabara, Y, Gu, D, Zhu, D, Haiman, CA, Mo, Z, Gao, Y-T, Saw, S-M, Go, M-J, Takeuchi, F, Chang, L-C, Kokubo, Y, Liang, J, Hao, M, Le Marchand, L, Zhang, Y, Hu, Y, Wong, T-Y, Long, J, Han, B-G, Kubo, M, Yamamoto, K, Su, M-H, Miki, T, Henderson, BE, Song, H, Tan, A, He, J, Ng, DP-K, Cai, Q, Tsunoda, T, Tsai, F-J, Iwai, N, Chen, GK, Shi, J, Xu, J, Sim, X, Xiang, Y-B, Maeda, S, Ong, RTH, Li, C, Nakamura, Y, Aung, T, Kamatani, N, Liu, J-J, Lu, W, Yokota, M, Seielstad, M, Fann, CSJ, Wu, J-Y, Lee, J-Y, Hu, FB, Tanaka, T, Tai, ES, and Shu, X-O
- Abstract
Multiple genetic loci associated with obesity or body mass index (BMI) have been identified through genome-wide association studies conducted predominantly in populations of European ancestry. We performed a meta-analysis of associations between BMI and approximately 2.4 million SNPs in 27,715 east Asians, which was followed by in silico and de novo replication studies in 37,691 and 17,642 additional east Asians, respectively. We identified ten BMI-associated loci at genome-wide significance (P < 5.0 × 10(-8)), including seven previously identified loci (FTO, SEC16B, MC4R, GIPR-QPCTL, ADCY3-DNAJC27, BDNF and MAP2K5) and three novel loci in or near the CDKAL1, PCSK1 and GP2 genes. Three additional loci nearly reached the genome-wide significance threshold, including two previously identified loci in the GNPDA2 and TFAP2B genes and a newly identified signal near PAX6, all of which were associated with BMI with P < 5.0 × 10(-7). Findings from this study may shed light on new pathways involved in obesity and demonstrate the value of conducting genetic studies in non-European populations.
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- 2012
9. Identification, replication, and fine-mapping of loci associated with adult height in individuals of African ancestry
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N'Diaye, A, Chen, GK, Palmer, CD, Ge, B, Tayo, B, Mathias, RA, Ding, J, Nalls, MA, Adeyemo, A, Adoue, V, Ambrosone, CB, Atwood, L, Bandera, EV, Becker, LC, Berndt, SI, Bernstein, L, Blot, WJ, Boerwinkle, E, Britton, A, Casey, G, Chanock, SJ, Demerath, E, Deming, SL, Diver, WR, Fox, C, Harris, TB, Hernandez, DG, Hu, JJ, Ingles, SA, John, EM, Johnson, C, Keating, B, Kittles, RA, Kolonel, LN, Kritchevsky, SB, Marchand, L, Lohman, K, Liu, J, Millikan, RC, Murphy, A, Musani, S, Neslund-Dudas, C, North, KE, Nyante, S, Ogunniyi, A, Ostrander, EA, Papanicolaou, G, Patel, S, Pettaway, CA, Press, MF, Redline, S, Rodriguez-Gil, JL, Rotimi, C, Rybicki, BA, Salako, B, Schreiner, PJ, Signorello, LB, Singleton, AB, Stanford, JL, Stram, AH, Stram, DO, Strom, SS, Suktitipat, B, Thun, MJ, Witte, JS, Yanek, LR, Ziegler, RG, Zheng, W, Zhu, X, Zmuda, JM, Zonderman, AB, Evans, MK, Liu, Y, Becker, DM, Cooper, RS, Pastinen, T, Henderson, BE, Hirschhorn, JN, Lettre, G, Haiman, CA, N'Diaye, A, Chen, GK, Palmer, CD, Ge, B, Tayo, B, Mathias, RA, Ding, J, Nalls, MA, Adeyemo, A, Adoue, V, Ambrosone, CB, Atwood, L, Bandera, EV, Becker, LC, Berndt, SI, Bernstein, L, Blot, WJ, Boerwinkle, E, Britton, A, Casey, G, Chanock, SJ, Demerath, E, Deming, SL, Diver, WR, Fox, C, Harris, TB, Hernandez, DG, Hu, JJ, Ingles, SA, John, EM, Johnson, C, Keating, B, Kittles, RA, Kolonel, LN, Kritchevsky, SB, Marchand, L, Lohman, K, Liu, J, Millikan, RC, Murphy, A, Musani, S, Neslund-Dudas, C, North, KE, Nyante, S, Ogunniyi, A, Ostrander, EA, Papanicolaou, G, Patel, S, Pettaway, CA, Press, MF, Redline, S, Rodriguez-Gil, JL, Rotimi, C, Rybicki, BA, Salako, B, Schreiner, PJ, Signorello, LB, Singleton, AB, Stanford, JL, Stram, AH, Stram, DO, Strom, SS, Suktitipat, B, Thun, MJ, Witte, JS, Yanek, LR, Ziegler, RG, Zheng, W, Zhu, X, Zmuda, JM, Zonderman, AB, Evans, MK, Liu, Y, Becker, DM, Cooper, RS, Pastinen, T, Henderson, BE, Hirschhorn, JN, Lettre, G, and Haiman, CA
- Abstract
Adult height is a classic polygenic trait of high heritability (h 2 ~0.8). More than 180 single nucleotide polymorphisms (SNPs), identified mostly in populations of European descent, are associated with height. These variants convey modest effects and explain ~10% of the variance in height. Discovery efforts in other populations, while limited, have revealed loci for height not previously implicated in individuals of European ancestry. Here, we performed a meta-analysis of genome-wide association (GWA) results for adult height in 20,427 individuals of African ancestry with replication in up to 16,436 African Americans. We found two novel height loci (Xp22-rs12393627, P = 3.4×10 -12 and 2p14-rs4315565, P = 1.2×10 -8). As a group, height associations discovered in European-ancestry samples replicate in individuals of African ancestry (P = 1.7×10 -4 for overall replication). Fine-mapping of the European height loci in African-ancestry individuals showed an enrichment of SNPs that are associated with expression of nearby genes when compared to the index European height SNPs (P<0.01). Our results highlight the utility of genetic studies in non-European populations to understand the etiology of complex human diseases and traits. © 2011 N'Diaye et al.
- Published
- 2011
10. The Bph45 Gene Confers Resistance against Brown Planthopper in Rice by Reducing the Production of Limonene.
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Li CP, Wu DH, Huang SH, Meng M, Shih HT, Lai MH, Chen LJ, Jena KK, Hechanova SL, Ke TJ, Chiu TY, Tsai ZY, Chen GK, Tsai KC, and Leu WM
- Subjects
- Animals, Genes, Plant, Limonene, Plant Diseases genetics, Hemiptera genetics, Oryza genetics
- Abstract
Brown planthopper (BPH), a monophagous phloem feeder, consumes a large amount of photoassimilates in rice and causes wilting. A near-isogenic line ‘TNG71-Bph45’ was developed from the Oryza sativa japonica variety ‘Tainung 71 (TNG71) carrying a dominant BPH-resistance locus derived from Oryza nivara (IRGC 102165) near the centromere of chromosome 4. We compared the NIL (TNG71-Bph45) and the recurrent parent to explore how the Bph45 gene confers BPH resistance. We found that TNG71-Bph45 is less attractive to BPH at least partially because it produces less limonene. Chiral analysis revealed that the major form of limonene in both rice lines was the L-form. However, both L- and D-limonene attracted BPH when applied exogenously to TNG71-Bph45 rice. The transcript amounts of limonene synthase were significantly higher in TNG71 than in TNG71-Bph45 and were induced by BPH infestation only in the former. Introgression of the Bph45 gene into another japonica variety, Tainan 11, also resulted in a low limonene content. Moreover, several dominantly acting BPH resistance genes introduced into the BPH-sensitive IR24 line compromised its limonene-producing ability and concurrently decreased its attractiveness to BPH. These observations suggest that reducing limonene production may be a common resistance strategy against BPH in rice.
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- 2023
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11. [Exploration of the development direction of contemporary acupuncture-moxibustion school: acupuncture-moxibustion treatment for periarthritis of shoulder].
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Wang C, Chen GK, Zhang L, Tong L, and Li HT
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- Humans, Schools, Shoulder, Acupuncture Therapy methods, Moxibustion, Periarthritis therapy
- Abstract
Taking acupuncture-moxibustion for periarthritis of shoulder as an example, the characteristics of contemporary acupuncture-moxibustion school are analyzed in terms of the theories of syndrome treatment, acupoint selection, needle devices and acupuncture techniques, as well as the encountered questions during its development; and the exploratory suggestions are proposed. The contemporary acupuncture-moxibustion school should be developed in three aspects, i.e. constructing data platform, expanding inheritance model and formulating acupuncture-moxibustion standard.
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- 2022
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12. Stochastic Epigenetic Mutations Influence Parkinson's Disease Risk, Progression, and Mortality.
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Chen GK, Yan Q, Paul KC, Kusters CDJ, Folle AD, Furlong M, Keener A, Bronstein J, Horvath S, and Ritz B
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- Disease Progression, Epigenesis, Genetic, Humans, Mutation, Parkinson Disease genetics
- Abstract
Background: Stochastic epigenetic mutations (SEM) reflect a deviation from normal site-specific methylation patterns. Epigenetic mutation load (EML) captures the accumulation of SEMs across an individual's genome and may reflect dysfunction of the epigenetic maintenance system in response to epigenetic challenges., Objective: We investigate whether EML is associated with PD risk and time to events (i.e., death and motor symptom decline)., Methods: We employed logistic regression and Cox proportional hazards regression to assess the association between EML and several outcomes. Our analyses are based on 568 PD patients and 238 controls from the Parkinson's disease, Environment and Genes (PEG) study, for whom blood-based methylation data was available., Results: We found an association for PD onset and EML in all genes (OR = 1.90; 95%CI 1.52-2.37) and PD-related genes (OR = 1.87; 95%CI 1.50-2.32). EML was also associated with time to a minimum score of 35 points on the motor UPDRS exam (OR = 1.28; 95%CI 1.06-1.56) and time to death (OR = 1.29, 95%CI 1.11-1.49). An analysis of PD related genes only revealed five intragenic hotspots of high SEM density associated with PD risk., Conclusion: Our findings suggest an enrichment of methylation dysregulation in PD patients in general and specifically in five PD related genes. EML may also be associated with time to death and motor symptom progression in PD patients.
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- 2022
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13. Using 3D photogrammetry to quantify the subtle differences of coral reefs under the impacts of marine activities.
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Chen GK and Dai CF
- Subjects
- Animals, Ecosystem, Photogrammetry, Seawater, Taiwan, Anthozoa, Coral Reefs
- Abstract
Marine activities may cause the degradation of coral reefs. The composition of benthic communities and seawater quality have been commonly used as the proxies to assess the impacts of marine activities. However, these proxies may not be able to detect the subtle differences within homogeneous environment. We used photogrammetry to quantify the subtle differences of structural complexity between heavily and lightly trafficked sites at Wanlitong, southern Taiwan. Our study demonstrated that the impacts of marine activities can be detected within tens of meters through quantifying structural complexity of coral reefs. Vector ruggedness measure (VRM) is a more suitable metric than conventional linear rugosity to detect such impacts. The correlations between structural complexity and coral cover have variances while comparing with previous studies. The results show that using photogrammetry to quantify the structure of coral reefs can provide a novel aspect to evaluate the subtle differences caused by marine activities., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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14. [Hotspots and trends of Ophiopogonis Radix based on CiteSpace knowledge map].
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Zeng ZL, Tong L, Liu SH, Zhang L, Gao HJ, Chen GK, and Zhang HM
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- China, Data Mining, Humans, Plant Roots, Medicine, Chinese Traditional, Publications
- Abstract
Ophiopogonis Radix is an important Yin-nourishing drug in traditional Chinese medicine(TCM), with the effects of nourishing Yin, promoting fluid production, clearing away heart-fire, and relieving restlessness. It is widely used in clinical practice due to its multiple chemical components and pharmacological effects. The technique "mapping knowledge domains" is an effective tool to quantitatively and objectively visualize the development frontiers and trends of certain disciplines. In this study, TCM research papers related to Ophiopogonis Radix were retrieved from Web of Science(WoS) and CNKI, and the research institutions, journals, and keywords involved were visualized and analyzed using the scientometric software CiteSpace. The co-occurrence network of related research on Ophiopogonis Radix was constructed, and the Ophiopogonis Radix-disease-target network was plotted using Cytoscape 3.8.2. The hot topics in Chinese and English papers were analyzed and the shortcomings in the research on Ophiopogonis Radix were summed up. Furthermore, the development trends were discussed. A total of 1 403 Chinese papers and 292 English papers were included in this study. The analysis of research institutions showed that Beijing University of Chinese Medicine and China Pharmaceutical University were the two research institutions with the largest numbers of papers published. The analysis of journals showed that Hebei Journal of Traditional Chinese Medicine and Journal of Asian Natural Products Research were the two journals with the highest numbers of papers concerning Ophiopogonis Radix. The keyword analysis showed that the research contents of Chinese papers focused on the analysis of medication regularity and clinical observation trials, while the English papers focused on component analysis and pharmacological investigation. Data mining and apoptosis-based pharmacological mechanism might be the research trends in the future.
- Published
- 2021
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15. Isomer-specific kinetics of the C + + H 2 O reaction at the temperature of interstellar clouds.
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Yang T, Li A, Chen GK, Yao Q, Suits AG, Guo H, Hudson ER, and Campbell WC
- Abstract
The reaction C
+ + H2 O → HCO+ /HOC+ + H is one of the most important astrophysical sources of HOC+ ions, considered a marker for interstellar molecular clouds exposed to intense ultraviolet or x-ray radiation. Despite much study, there is no consensus on rate constants for formation of the formyl ion isomers in this reaction. This is largely due to difficulties in laboratory study of ion-molecule reactions under relevant conditions. Here, we use a novel experimental platform combining a cryogenic buffer-gas beam with an integrated, laser-cooled ion trap and high-resolution time-of-flight mass spectrometer to probe this reaction at the temperature of cold interstellar clouds. We report a reaction rate constant of k = 7.7(6) × 10-9 cm3 s-1 and a branching ratio of formation η = HOC+ /HCO+ = 2.1(4). Theoretical calculations suggest that this branching ratio is due to the predominant formation of HOC+ followed by isomerization of products with internal energy over the isomerization barrier., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)- Published
- 2021
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16. Effects of biochar and crop straws on the bioavailability of cadmium in contaminated soil.
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Chen X, He HZ, Chen GK, and Li HS
- Abstract
Numerous studies have been investigated the potential of biochar (BC) derived from various materials and crop straw (CS) to decrease the bioavailability of heavy metals in soil contaminated with cadmium (Cd), and thereby reduce their potential risk to human health and the ecological environment. However, little attention has been given to the comparison of heavy metal remediation efficiency using BC and CS such as peanut vine (PV) and rice straw (RS), especially in soil contaminated with Cd. Here, we explore if Cd bioavailability is affected in contaminated soil by BC and CS. Peanuts were grown in plastic pots, which contained BC or CS at 5% (dry weight, w/w) in controlled environment mesocosms. The bioavailability of Cd in contaminated soil was measured by Cd concentration in the plant and the concentrations of various forms of Cd in the soil. At the same plant age, growth with BC (compared with PV and RS) led to 13.56% and 8.28% lower rates of Cd content in the aboveground parts, 40.65% and 35.67% lower rates of Cd content in the seeds, yet 9.08% and 7.09% lower rates of Cd content in the roots, yet 35.80% and 28.48% lower rates of exchangeable Cd content in the soil. Moreover, BC amendment enhanced the biomass of peanut and physiological quality. Thus, BC had a greater impact on immobilizing Cd in the soil. The results imply that BC was more significantly (P < 0.05) remarkable in decreasing the Cd bioavailability and improving the biomass of peanut. BC has greater potential for enhancing soil quality and promoting peanut growth. In conclusion, this research demonstrates an understanding of employing BC as a promising inexpensive and eco-friendly amendment to remediate soil contaminated with Cd.
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- 2020
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17. Human activities have opposing effects on distributions of narrow-ranged and widespread plant species in China.
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Xu WB, Svenning JC, Chen GK, Zhang MG, Huang JH, Chen B, Ordonez A, and Ma KP
- Abstract
Human activities have shaped large-scale distributions of many species, driving both range contractions and expansions. Species differ naturally in range size, with small-range species concentrated in particular geographic areas and potentially deviating ecologically from widespread species. Hence, species' responses to human activities may be influenced by their geographic range sizes, but if and how this happens are poorly understood. Here, we use a comprehensive distribution database and species distribution modeling to examine if and how human activities have affected the extent to which 9,701 vascular plants fill their climatic potential ranges in China. We find that narrow-ranged species have lower range filling and widespread species have higher range filling in the human-dominated southeastern part of China, compared with their counterparts distributed in the less human-influenced northwestern part. Variations in range filling across species and space are strongly associated with indicators of human activities (human population density, human footprint, and proportion of cropland) even after controlling for alternative drivers. Importantly, narrow-ranged and widespread species show negative and positive range-filling relationships to these human indicators, respectively. Our results illustrate that floras risk biotic homogenization as a consequence of anthropogenic activities, with narrow-ranged species becoming replaced by widespread species. Because narrow-ranged species are more numerous than widespread species in nature, negative impacts of human activities will be prevalent. Our findings highlight the importance of establishing more protected areas and zones of reduced human activities to safeguard the rich flora of China.
- Published
- 2019
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18. Isotope-selective chemistry in the Be + ( 2 S 1/2 ) + HOD → BeOD + /BeOH + + H/D reaction.
- Author
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Chen GK, Xie C, Yang T, Li A, Suits AG, Hudson ER, Campbell WC, and Guo H
- Abstract
Low temperature reactions between laser-cooled Be+(2S1/2) ions and partially deuterated water (HOD) molecules have been investigated using an ion trap and interpreted with zero-point corrected quasi-classical trajectory calculations on a highly accurate global potential energy surface for the ground electronic state. Both product channels have been observed for the first time, and the branching to BeOD+ + H is found to be 0.58 ± 0.14. The experimental observation is reproduced by both quasi-classical trajectory and statistical calculations. Theoretical analyses reveal that the branching to the two product channels is largely due to the availability of open states in each channel.
- Published
- 2019
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19. Newly Identified Aplysia SPTR-Gene Family-Derived Peptides: Localization and Function.
- Author
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Zhang G, Yuan WD, Vilim FS, Romanova EV, Yu K, Yin SY, Le ZW, Xue YY, Chen TT, Chen GK, Chen SA, Cropper EC, Sweedler JV, Weiss KR, and Jing J
- Subjects
- Amino Acid Sequence, Animals, Aplysia cytology, Computational Biology, Eating physiology, Ganglia, Invertebrate cytology, Ganglia, Invertebrate metabolism, Male, Membrane Potentials physiology, Neurons cytology, Neurons metabolism, Neuropeptides genetics, Protein Processing, Post-Translational, Rats, Sprague-Dawley, Sequence Alignment, Aplysia metabolism, Motor Activity physiology, Neuropeptides metabolism
- Abstract
When individual neurons in a circuit contain multiple neuropeptides, these peptides can target different sets of follower neurons. This endows the circuit with a certain degree of flexibility. Here we identified a novel family of peptides, the Aplysia SPTR-Gene Family-Derived peptides (apSPTR-GF-DPs). We demonstrated apSPTR-GF-DPs, particularly apSPTR-GF-DP2, are expressed in the Aplysia CNS using immunohistochemistry and MALDI-TOF MS. Furthermore, apSPTR-GF-DP2 is present in single projection neurons, e.g., in the cerebral-buccal interneuron-12 (CBI-12). Previous studies have demonstrated that CBI-12 contains two other peptides, FCAP/CP2. In addition, CBI-12 and CP2 promote shortening of the protraction phase of motor programs. Here, we demonstrate that FCAP shortens protraction. Moreover, we show that apSPTR-GF-DP2 also shortens protraction. Surprisingly, apSPTR-GF-DP2 does not increase the excitability of retraction interneuron B64. B64 terminates protraction and is modulated by FCAP/CP2 and CBI-12. Instead, we show that apSPTR-GF-DP2 and CBI-12 increase B20 excitability and B20 activity can shorten protraction. Taken together, these data indicate that different CBI-12 peptides target different sets of pattern-generating interneurons to exert similar modulatory actions. These findings provide the first definitive evidence for SPTR-GF's role in modulation of feeding, and a form of molecular degeneracy by multiple peptide cotransmitters in single identified neurons.
- Published
- 2018
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20. Optical Control of Reactions between Water and Laser-Cooled Be + Ions.
- Author
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Yang T, Li A, Chen GK, Xie C, Suits AG, Campbell WC, Guo H, and Hudson ER
- Abstract
We investigate reactions between laser-cooled Be
+ ions and room-temperature water molecules using an integrated ion trap and high-resolution time-of-flight mass spectrometer. This system allows simultaneous measurement of individual reaction rates that are resolved by reaction product. The rate coefficient of the Be+ (2 S1/2 ) + H2 O → BeOH+ + H reaction is measured for the first time and is found to be approximately two times smaller than predicted by an ion-dipole capture model. Zero-point-corrected quasi-classical trajectory calculations on a highly accurate potential energy surface for the ground electronic state reveal that the reaction is capture-dominated, but a submerged barrier in the product channel lowers the reactivity. Furthermore, laser excitation of the ions from the2 S1/2 ground state to the2 P3/2 state opens new reaction channels, and we report the rate and branching ratio of the Be+ (2 P3/2 ) + H2 O → BeOH+ + H and H2 O+ + Be reactions. The excited-state reactions are nonadiabatic in nature.- Published
- 2018
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21. Iterative hard thresholding for model selection in genome-wide association studies.
- Author
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Keys KL, Chen GK, and Lange K
- Subjects
- Algorithms, Body Mass Index, Cholesterol, HDL genetics, Cholesterol, LDL genetics, Humans, Phenotype, Polymorphism, Single Nucleotide, Triglycerides genetics, Genome-Wide Association Study, Models, Genetic
- Abstract
A genome-wide association study (GWAS) correlates marker and trait variation in a study sample. Each subject is genotyped at a multitude of SNPs (single nucleotide polymorphisms) spanning the genome. Here, we assume that subjects are randomly collected unrelateds and that trait values are normally distributed or can be transformed to normality. Over the past decade, geneticists have been remarkably successful in applying GWAS analysis to hundreds of traits. The massive amount of data produced in these studies present unique computational challenges. Penalized regression with the ℓ
1 penalty (LASSO) or minimax concave penalty (MCP) penalties is capable of selecting a handful of associated SNPs from millions of potential SNPs. Unfortunately, model selection can be corrupted by false positives and false negatives, obscuring the genetic underpinning of a trait. Here, we compare LASSO and MCP penalized regression to iterative hard thresholding (IHT). On GWAS regression data, IHT is better at model selection and comparable in speed to both methods of penalized regression. This conclusion holds for both simulated and real GWAS data. IHT fosters parallelization and scales well in problems with large numbers of causal markers. Our parallel implementation of IHT accommodates SNP genotype compression and exploits multiple CPU cores and graphics processing units (GPUs). This allows statistical geneticists to leverage commodity desktop computers in GWAS analysis and to avoid supercomputing., Availability: Source code is freely available at https://github.com/klkeys/IHT.jl., (© 2017 WILEY PERIODICALS, INC.)- Published
- 2017
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22. cit: hypothesis testing software for mediation analysis in genomic applications.
- Author
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Millstein J, Chen GK, and Breton CV
- Subjects
- Gene Library, Genome, Models, Theoretical, Genomics, Software
- Abstract
Motivation: The challenges of successfully applying causal inference methods include: (i) satisfying underlying assumptions, (ii) limitations in data/models accommodated by the software and (iii) low power of common multiple testing approaches., Results: The causal inference test (CIT) is based on hypothesis testing rather than estimation, allowing the testable assumptions to be evaluated in the determination of statistical significance. A user-friendly software package provides P-values and optionally permutation-based FDR estimates (q-values) for potential mediators. It can handle single and multiple binary and continuous instrumental variables, binary or continuous outcome variables and adjustment covariates. Also, the permutation-based FDR option provides a non-parametric implementation., Conclusion: Simulation studies demonstrate the validity of the cit package and show a substantial advantage of permutation-based FDR over other common multiple testing strategies., Availability and Implementation: The cit open-source R package is freely available from the CRAN website (https://cran.r-project.org/web/packages/cit/index.html) with embedded C ++ code that utilizes the GNU Scientific Library, also freely available (http://www.gnu.org/software/gsl/)., Contact: joshua.millstein@usc.edu, Supplementary Information: Supplementary data are available at Bioinformatics online., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2016
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23. Mapping adipose and muscle tissue expression quantitative trait loci in African Americans to identify genes for type 2 diabetes and obesity.
- Author
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Sajuthi SP, Sharma NK, Chou JW, Palmer ND, McWilliams DR, Beal J, Comeau ME, Ma L, Calles-Escandon J, Demons J, Rogers S, Cherry K, Menon L, Kouba E, Davis D, Burris M, Byerly SJ, Ng MC, Maruthur NM, Patel SR, Bielak LF, Lange LA, Guo X, Sale MM, Chan KH, Monda KL, Chen GK, Taylor K, Palmer C, Edwards TL, North KE, Haiman CA, Bowden DW, Freedman BI, Langefeld CD, and Das SK
- Subjects
- Adipose Tissue pathology, Adolescent, Adult, Black or African American genetics, Chromosome Mapping, Diabetes Mellitus, Type 2 pathology, Female, Gene Expression Regulation, Genetic Predisposition to Disease, Genome-Wide Association Study, Humans, Male, Middle Aged, Muscles pathology, Obesity pathology, Adipose Tissue metabolism, Diabetes Mellitus, Type 2 genetics, Muscles metabolism, Obesity genetics, Quantitative Trait Loci genetics
- Abstract
Relative to European Americans, type 2 diabetes (T2D) is more prevalent in African Americans (AAs). Genetic variation may modulate transcript abundance in insulin-responsive tissues and contribute to risk; yet, published studies identifying expression quantitative trait loci (eQTLs) in African ancestry populations are restricted to blood cells. This study aims to develop a map of genetically regulated transcripts expressed in tissues important for glucose homeostasis in AAs, critical for identifying the genetic etiology of T2D and related traits. Quantitative measures of adipose and muscle gene expression, and genotypic data were integrated in 260 non-diabetic AAs to identify expression regulatory variants. Their roles in genetic susceptibility to T2D, and related metabolic phenotypes, were evaluated by mining GWAS datasets. eQTL analysis identified 1971 and 2078 cis-eGenes in adipose and muscle, respectively. Cis-eQTLs for 885 transcripts including top cis-eGenes CHURC1, USMG5, and ERAP2 were identified in both tissues. 62.1 % of top cis-eSNPs were within ±50 kb of transcription start sites and cis-eGenes were enriched for mitochondrial transcripts. Mining GWAS databases revealed association of cis-eSNPs for more than 50 genes with T2D (e.g. PIK3C2A, RBMS1, UFSP1), gluco-metabolic phenotypes (e.g. INPP5E, SNX17, ERAP2, FN3KRP), and obesity (e.g. POMC, CPEB4). Integration of GWAS meta-analysis data from AA cohorts revealed the most significant association for cis-eSNPs of ATP5SL and MCCC1 genes, with T2D and BMI, respectively. This study developed the first comprehensive map of adipose and muscle tissue eQTLs in AAs (publically accessible at https://mdsetaa.phs.wakehealth.edu ) and identified genetically regulated transcripts for delineating genetic causes of T2D, and related metabolic phenotypes.
- Published
- 2016
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24. Increased retinal mtDNA damage in the CFH variant associated with age-related macular degeneration.
- Author
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Ferrington DA, Kapphahn RJ, Leary MM, Atilano SR, Terluk MR, Karunadharma P, Chen GK, Ratnapriya R, Swaroop A, Montezuma SR, and Kenney MC
- Subjects
- Aged, Aged, 80 and over, Alleles, Case-Control Studies, Female, Genetic Predisposition to Disease, Genotype, Humans, Macular Degeneration metabolism, Macular Degeneration physiopathology, Male, Middle Aged, Polymerase Chain Reaction, Complement Factor H genetics, DNA Damage physiology, DNA, Mitochondrial, Macular Degeneration genetics, Retinal Pigment Epithelium
- Abstract
Age-related macular degeneration (AMD) is a major cause of blindness among the elderly in the developed world. Genetic analysis of AMD has identified 34 high-risk loci associated with AMD. The genes at these high risk loci belong to diverse biological pathways, suggesting different mechanisms leading to AMD pathogenesis. Thus, therapies targeting a single pathway for all AMD patients will likely not be universally effective. Recent evidence suggests defects in mitochondria (mt) of the retinal pigment epithelium (RPE) may constitute a key pathogenic event in some AMD patients. The purpose of this study is to determine if individuals with a specific genetic background have a greater propensity for mtDNA damage. We used human eyebank tissues from 76 donors with AMD and 42 age-matched controls to determine the extent of mtDNA damage in the RPE that was harvested from the macula using a long extension polymerase chain reaction assay. Genotype analyses were performed for ten common AMD-associated nuclear risk alleles (ARMS2, TNFRSF10A, CFH, C2, C3, APOE, CETP, LIPC, VEGF and COL10A1) and mtDNA haplogroups. Sufficient samples were available for genotype association with mtDNA damage for TNFRSF10A, CFH, CETP, VEGFA, and COL10A1. Our results show that AMD donors carrying the high risk allele for CFH (C) had significantly more mtDNA damage compared with donors having the wild-type genetic profile. The data from an additional 39 donors (12 controls and 27 AMD) genotyped for CFH alleles further supported these findings. Taken together, these studies provide the rationale for a more personalized approach for treating AMD by uncovering a significant correlation between the CFH high risk allele and accelerated mtDNA damage. Patients harboring this genetic risk factor may benefit from therapies that stabilize and protect the mt in the RPE., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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25. Identification and Characterization of Three Monilinia Species from Plum in China.
- Author
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Yin LF, Chen SN, Chen GK, Schnabel G, Du SF, Chen C, Li GQ, and Luo CX
- Abstract
In total, 112 Monilinia spp. single-spore isolates were collected from plum fruit (Prunus salicina) symptomatic for brown rot disease from Yunnan, Hubei, and Zhejiang provinces and Chongqing municipality, China between 2012 and 2014. Three distinct colony morphologies (phenotypes) were observed on potato dextrose agar and two isolates per phenotype were selected for further analysis. Colony color, colony shape, conidia size, number of germ tubes per conidia, and pathogenicity on plum were investigated. The ribosomal internal transcribed spacer regions 1 and 2 as well as a polymerase chain reaction-based method that amplified fragments of the glyceraldehyde-3-phosphate dehydrogenase (G3PDH) and β-tubulin (TUB2) genes were used to identify the isolates to the species level. The three phenotypes were identified to be three different species: Monilinia fructicola, Monilia mumecola, and Monilia yunnanensis. Phylogenetic analysis based on G3PDH and TUB2 nucleotide sequences revealed that isolates within species clustered together regardless of host or geographical origin, suggesting that these factors did not play an important role for the evolutionary separation of the described species.
- Published
- 2015
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26. al3c: high-performance software for parameter inference using Approximate Bayesian Computation.
- Author
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Stram AH, Marjoram P, and Chen GK
- Subjects
- Algorithms, Animals, Bayes Theorem, Monte Carlo Method, Models, Biological, Software
- Abstract
Motivation: The development of Approximate Bayesian Computation (ABC) algorithms for parameter inference which are both computationally efficient and scalable in parallel computing environments is an important area of research. Monte Carlo rejection sampling, a fundamental component of ABC algorithms, is trivial to distribute over multiple processors but is inherently inefficient. While development of algorithms such as ABC Sequential Monte Carlo (ABC-SMC) help address the inherent inefficiencies of rejection sampling, such approaches are not as easily scaled on multiple processors. As a result, current Bayesian inference software offerings that use ABC-SMC lack the ability to scale in parallel computing environments., Results: We present al3c, a C++ framework for implementing ABC-SMC in parallel. By requiring only that users define essential functions such as the simulation model and prior distribution function, al3c abstracts the user from both the complexities of parallel programming and the details of the ABC-SMC algorithm. By using the al3c framework, the user is able to scale the ABC-SMC algorithm in parallel computing environments for his or her specific application, with minimal programming overhead., Availability and Implementation: al3c is offered as a static binary for Linux and OS-X computing environments. The user completes an XML configuration file and C++ plug-in template for the specific application, which are used by al3c to obtain the desired results. Users can download the static binaries, source code, reference documentation and examples (including those in this article) by visiting https://github.com/ahstram/al3c., Contact: astram@usc.edu, Supplementary Information: Supplementary data are available at Bioinformatics online., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2015
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27. Varietal differences in the growth of rice seedlings exposed to perchlorate and their antioxidative defense mechanisms.
- Author
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Chen GK, Li XB, He HZ, Li HS, and Zhang ZM
- Subjects
- Catalase metabolism, Cluster Analysis, Malondialdehyde metabolism, Oryza drug effects, Oryza growth & development, Peroxidases metabolism, Plant Roots drug effects, Plant Roots metabolism, Plant Shoots drug effects, Plant Shoots metabolism, Seedlings drug effects, Seedlings growth & development, Seedlings metabolism, Superoxide Dismutase metabolism, Antioxidants metabolism, Oryza metabolism, Oxidative Stress drug effects, Perchlorates toxicity
- Abstract
A hydroponic experiment was conducted to investigate perchlorate (ClO4 (-) ) phytotoxicity in different rice varieties. Considerable variations were observed when 24 rice varieties were treated with ClO4 (-) . The shoot height, root length, and biomass of most varieties were significantly reduced by ClO4 (-) . The roots were more sensitive than the shoots. Hierarchical clustering analysis demonstrated primarily 4 groups: ClO4 (-) -sensitive, medium ClO4 (-) -sensitive, medium ClO4 (-) tolerant, and ClO4 (-) -tolerant. Gannuoxiang (a ClO4 (-) -tolerant variety) and IR65598-112-2 (a ClO4 (-) -sensitive variety) were chosen to explore their antioxidant response when exposed to 0.2 mmol/L, 2.0 mmol/L, and 4.0 mmol/L ClO4 (-) . The results showed that the activities of superoxide dismutase and catalase increased in the shoots and roots of gannuoxiang with increasing doses of ClO4 (-) , but both of them decreased at higher concentrations of ClO4 (-) in IR65598-112-2. The addition of ClO4 (-) led to a significant increase in peroxidase activities for both of the varieties, whereas the increase was more pronounced in gannuoxiang than in IR65598-112-2. No significant difference was found in malondialdehyde (MDA) contents in gannuoxiang, whereas the addition of ClO4 (-) increased the MDA level significantly in IR65598-112-2. The results indicated that gannuoxiang has higher activities of antioxidant enzymes than IR65598-112-2 to cope with oxidative damage caused by ClO4 (-) stress, which may be the main cause of its high tolerance., (© 2015 SETAC.)
- Published
- 2015
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28. Methodological Considerations in Estimation of Phenotype Heritability Using Genome-Wide SNP Data, Illustrated by an Analysis of the Heritability of Height in a Large Sample of African Ancestry Adults.
- Author
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Chen F, He J, Zhang J, Chen GK, Thomas V, Ambrosone CB, Bandera EV, Berndt SI, Bernstein L, Blot WJ, Cai Q, Carpten J, Casey G, Chanock SJ, Cheng I, Chu L, Deming SL, Driver WR, Goodman P, Hayes RB, Hennis AJ, Hsing AW, Hu JJ, Ingles SA, John EM, Kittles RA, Kolb S, Leske MC, Millikan RC, Monroe KR, Murphy A, Nemesure B, Neslund-Dudas C, Nyante S, Ostrander EA, Press MF, Rodriguez-Gil JL, Rybicki BA, Schumacher F, Stanford JL, Signorello LB, Strom SS, Stevens V, Van Den Berg D, Wang Z, Witte JS, Wu SY, Yamamura Y, Zheng W, Ziegler RG, Stram AH, Kolonel LN, Le Marchand L, Henderson BE, Haiman CA, and Stram DO
- Subjects
- Female, Genome-Wide Association Study methods, Genotype, Humans, Linear Models, Male, Models, Genetic, Phenotype, Regression Analysis, Black or African American, Black People genetics, Body Height genetics, Polymorphism, Single Nucleotide genetics
- Abstract
Height has an extremely polygenic pattern of inheritance. Genome-wide association studies (GWAS) have revealed hundreds of common variants that are associated with human height at genome-wide levels of significance. However, only a small fraction of phenotypic variation can be explained by the aggregate of these common variants. In a large study of African-American men and women (n = 14,419), we genotyped and analyzed 966,578 autosomal SNPs across the entire genome using a linear mixed model variance components approach implemented in the program GCTA (Yang et al Nat Genet 2010), and estimated an additive heritability of 44.7% (se: 3.7%) for this phenotype in a sample of evidently unrelated individuals. While this estimated value is similar to that given by Yang et al in their analyses, we remain concerned about two related issues: (1) whether in the complete absence of hidden relatedness, variance components methods have adequate power to estimate heritability when a very large number of SNPs are used in the analysis; and (2) whether estimation of heritability may be biased, in real studies, by low levels of residual hidden relatedness. We addressed the first question in a semi-analytic fashion by directly simulating the distribution of the score statistic for a test of zero heritability with and without low levels of relatedness. The second question was addressed by a very careful comparison of the behavior of estimated heritability for both observed (self-reported) height and simulated phenotypes compared to imputation R2 as a function of the number of SNPs used in the analysis. These simulations help to address the important question about whether today's GWAS SNPs will remain useful for imputing causal variants that are discovered using very large sample sizes in future studies of height, or whether the causal variants themselves will need to be genotyped de novo in order to build a prediction model that ultimately captures a large fraction of the variability of height, and by implication other complex phenotypes. Our overall conclusions are that when study sizes are quite large (5,000 or so) the additive heritability estimate for height is not apparently biased upwards using the linear mixed model; however there is evidence in our simulation that a very large number of causal variants (many thousands) each with very small effect on phenotypic variance will need to be discovered to fill the gap between the heritability explained by known versus unknown causal variants. We conclude that today's GWAS data will remain useful in the future for causal variant prediction, but that finding the causal variants that need to be predicted may be extremely laborious.
- Published
- 2015
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29. Convex clustering: an attractive alternative to hierarchical clustering.
- Author
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Chen GK, Chi EC, Ranola JM, and Lange K
- Subjects
- Algorithms, Databases, Genetic, Gene Expression Profiling methods, Humans, Software, Cluster Analysis, Computational Biology methods, Pattern Recognition, Automated methods
- Abstract
The primary goal in cluster analysis is to discover natural groupings of objects. The field of cluster analysis is crowded with diverse methods that make special assumptions about data and address different scientific aims. Despite its shortcomings in accuracy, hierarchical clustering is the dominant clustering method in bioinformatics. Biologists find the trees constructed by hierarchical clustering visually appealing and in tune with their evolutionary perspective. Hierarchical clustering operates on multiple scales simultaneously. This is essential, for instance, in transcriptome data, where one may be interested in making qualitative inferences about how lower-order relationships like gene modules lead to higher-order relationships like pathways or biological processes. The recently developed method of convex clustering preserves the visual appeal of hierarchical clustering while ameliorating its propensity to make false inferences in the presence of outliers and noise. The solution paths generated by convex clustering reveal relationships between clusters that are hidden by static methods such as k-means clustering. The current paper derives and tests a novel proximal distance algorithm for minimizing the objective function of convex clustering. The algorithm separates parameters, accommodates missing data, and supports prior information on relationships. Our program CONVEXCLUSTER incorporating the algorithm is implemented on ATI and nVidia graphics processing units (GPUs) for maximal speed. Several biological examples illustrate the strengths of convex clustering and the ability of the proximal distance algorithm to handle high-dimensional problems. CONVEXCLUSTER can be freely downloaded from the UCLA Human Genetics web site at http://www.genetics.ucla.edu/software/.
- Published
- 2015
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30. A comprehensive examination of breast cancer risk loci in African American women.
- Author
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Feng Y, Stram DO, Rhie SK, Millikan RC, Ambrosone CB, John EM, Bernstein L, Zheng W, Olshan AF, Hu JJ, Ziegler RG, Nyante S, Bandera EV, Ingles SA, Press MF, Deming SL, Rodriguez-Gil JL, Palmer JR, Olopade OI, Huo D, Adebamowo CA, Ogundiran T, Chen GK, Stram A, Park K, Rand KA, Chanock SJ, Le Marchand L, Kolonel LN, Conti DV, Easton D, Henderson BE, and Haiman CA
- Subjects
- Female, Genetic Loci, Genetic Variation, Genome-Wide Association Study, Humans, Polymorphism, Single Nucleotide, Receptors, Estrogen genetics, Black or African American genetics, Breast Neoplasms genetics, Genetic Predisposition to Disease
- Abstract
Genome-wide association studies have identified 73 breast cancer risk variants mainly in European populations. Given considerable differences in linkage disequilibrium structure between populations of European and African ancestry, the known risk variants may not be informative for risk in African ancestry populations. In a previous fine-mapping investigation of 19 breast cancer loci, we were able to identify SNPs in four regions that better captured risk associations in African American women. In this study of breast cancer in African American women (3016 cases, 2745 controls), we tested an additional 54 novel breast cancer risk variants. Thirty-eight variants (70%) were found to have an association with breast cancer in the same direction as previously reported, with eight (15%) replicating at P < 0.05. Through fine-mapping, in three regions (1q32, 3p24, 10q25), we identified variants that better captured associations with overall breast cancer or estrogen receptor positive disease. We also observed suggestive associations with variants (at P < 5 × 10(-6)) in three separate regions (6q25, 14q13, 22q12) that may represent novel risk variants. Directional consistency of association observed for ∼65-70% of currently known genetic variants for breast cancer in women of African ancestry implies a shared functional common variant at most loci. To validate and enhance the spectrum of alleles that define associations at the known breast cancer risk loci, as well as genome-wide, will require even larger collaborative efforts in women of African ancestry., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2014
- Full Text
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31. First Report of Brown Rot Caused by Monilia mumecola on Chinese Sour Cherry in Chongqing Municipality, China.
- Author
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Yin LF, Chen GK, Chen SN, Du SF, Li GQ, and Luo CX
- Abstract
Cherry is widely planted in China, from Liaoning, Beijing, Hebei, Shandong, Zhejiang, Jiangsu, and Anhui provinces (eastern China), to Shaanxi, Sichuan, Chongqing, and Guizhou provinces (western China). The brown rot fungus Monilinia fructigena causes considerable production losses in cherry production in Liaoning Province (3). In May 2013, Chinese sour cherry (Prunus pseudocerasus) cv. Wupi displaying symptoms of brown rot was found in an orchard in Chongqing municipality. Diseased cherry fruit had a brown rot sporulating with grayish, conidial tufts. The fruit later succumbed to the soft rot or shivered and became a mummy. Single-spore isolations on PDA resulted in colonies with concentric rings of pigmented mycelium with lobbed margins. Conidia were broadly ellipsoid to subglobose, occasionally even globose, with an average size of 16 × 12.7 μm. Multiple germ tubes were produced from each conidium, a germination pattern unique to Monilia mumecola (1,2,4). The pathogen identity was confirmed by multiplex PCR as described by Hu et al. (2). The PCR resulted in a 712-bp amplicon, which is diagnostic of M. mumecola. Further sequencing of the internal transcribed spacer (ITS) region 1 and 2 and 5.8S gene further indicated 100% identity with that of M. mumecola isolates from China (Accession No. HQ908786) and from Japan (AB125613, AB125614, and AB125620). Koch's postulates were confirmed by inoculating mature cherry fruit with mycelia plugs. Inoculated fruit were placed in a sterilized moist chamber, and incubated at 22°C with 12 h light/dark cycle. Inoculated fruit developed typical brown rot symptoms only 2 days after inoculation, while the control fruit, inoculated with a sterile PDA plug, remained healthy. The pathogen isolated from inoculated symptomatic fruit was confirmed to be M. mumecola based on morphological characteristics and germination pattern. It should be noted that the conidia on inoculated fruit showed an average size of 20 × 15.3 μm, significantly bigger than that of from PDA, and most produced more than three germ tubes. The inoculation experiments were performed in triplicates. M. mumecola was first reported as the causal agent of brown rot of mume in Japan in 2004 (1). Later studies demonstrated that it is also pathogen on other stone fruits, e.g., peach, nectarine (2), and apricot (4). To our knowledge, this is the first report of cherry brown fruit rot caused by M. mumecola, and the first report of M. mumecola in Chongqing municipality. References: (1) Y. Harada et al. J. Gen. Plant Pathol. 70:297, 2004. (2) M. J. Hu et al. Plos One 6(9): e24990, 2011. (3) Z. H. Liu et al. J. Fruit Sci. 29:423, 2012. (4) L. F. Yin et al. Plant Dis. 98:694, 2014.
- Published
- 2014
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32. Meta-analysis of loci associated with age at natural menopause in African-American women.
- Author
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Chen CT, Liu CT, Chen GK, Andrews JS, Arnold AM, Dreyfus J, Franceschini N, Garcia ME, Kerr KF, Li G, Lohman KK, Musani SK, Nalls MA, Raffel LJ, Smith J, Ambrosone CB, Bandera EV, Bernstein L, Britton A, Brzyski RG, Cappola A, Carlson CS, Couper D, Deming SL, Goodarzi MO, Heiss G, John EM, Lu X, Le Marchand L, Marciante K, Mcknight B, Millikan R, Nock NL, Olshan AF, Press MF, Vaiyda D, Woods NF, Taylor HA, Zhao W, Zheng W, Evans MK, Harris TB, Henderson BE, Kardia SL, Kooperberg C, Liu Y, Mosley TH, Psaty B, Wellons M, Windham BG, Zonderman AB, Cupples LA, Demerath EW, Haiman C, Murabito JM, and Rajkovic A
- Subjects
- Age Factors, Chromosomes, Human, Female, Genetic Loci, Genetic Variation, Genome-Wide Association Study, Humans, United States, Black or African American genetics, Menopause ethnology, Menopause genetics, White People genetics
- Abstract
Age at menopause marks the end of a woman's reproductive life and its timing associates with risks for cancer, cardiovascular and bone disorders. GWAS and candidate gene studies conducted in women of European ancestry have identified 27 loci associated with age at menopause. The relevance of these loci to women of African ancestry has not been previously studied. We therefore sought to uncover additional menopause loci and investigate the relevance of European menopause loci by performing a GWAS meta-analysis in 6510 women with African ancestry derived from 11 studies across the USA. We did not identify any additional loci significantly associated with age at menopause in African Americans. We replicated the associations between six loci and age at menopause (P-value < 0.05): AMHR2, RHBLD2, PRIM1, HK3/UMC1, BRSK1/TMEM150B and MCM8. In addition, associations of 14 loci are directionally consistent with previous reports. We provide evidence that genetic variants influencing reproductive traits identified in European populations are also important in women of African ancestry residing in USA., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
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- 2014
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33. [Expression and clinical significance of p53 and autophagy-related gene Beclin1 in salivary pleomorphic adenoma and carcinoma in pleomorphic adenoma].
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Chen GK, Wu YH, Zhang SZ, Zhang DS, Huang SY, and Wen J
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- Apoptosis, Apoptosis Regulatory Proteins, Beclin-1, Carcinoma, Humans, Immunohistochemistry, Membrane Proteins, Tumor Suppressor Protein p53, Adenoma, Pleomorphic, Autophagy, Salivary Gland Neoplasms
- Abstract
Purpose: To investigate the expression of p53 and Beclin1 in salivary pleomorphic adenoma (PA) and its clinical significance., Methods: The expression of p53 and Beclin1 were assessed by immunohistochemistry in 108 cases of PA and 20 cases of carcinoma in pleomorphic adenoma(CIPA). The results were used to analyze the relationship between gene expressions and the development of PA as well as the clinical pathological features. Statistic analysis was conducted with SPSS 20.0 software package., Results: The positive expressions of p53 in PA samples (9%) were significantly lower than that in CIPA(14%) (P<0.001). The positive expressions of autophagy-related gene Beclin1 in PA samples(91%) were significantly higher than that CIPA (11%) (P<0.001). The expression levels of these genes were not associated with gender, age, clinical course, tumor size, and location of PA(P>0.05). There was a negative correlation between p53 and Beclin1 expression in PA (r=-0.330,P<0.05)., Conclusions: The expression levels of Beclin1 and p53 protein are closely related to the development of PA. Reduced autophagy and enhanced anti apoptosis coexist in the process of tumor formation. Thus, raising the autophagy ability may become another alternative choice for cancer therapy.
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- 2014
34. Discovering epistasis in large scale genetic association studies by exploiting graphics cards.
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Chen GK and Guo Y
- Abstract
Despite the enormous investments made in collecting DNA samples and generating germline variation data across thousands of individuals in modern genome-wide association studies (GWAS), progress has been frustratingly slow in explaining much of the heritability in common disease. Today's paradigm of testing independent hypotheses on each single nucleotide polymorphism (SNP) marker is unlikely to adequately reflect the complex biological processes in disease risk. Alternatively, modeling risk as an ensemble of SNPs that act in concert in a pathway, and/or interact non-additively on log risk for example, may be a more sensible way to approach gene mapping in modern studies. Implementing such analyzes genome-wide can quickly become intractable due to the fact that even modest size SNP panels on modern genotype arrays (500k markers) pose a combinatorial nightmare, require tens of billions of models to be tested for evidence of interaction. In this article, we provide an in-depth analysis of programs that have been developed to explicitly overcome these enormous computational barriers through the use of processors on graphics cards known as Graphics Processing Units (GPU). We include tutorials on GPU technology, which will convey why they are growing in appeal with today's numerical scientists. One obvious advantage is the impressive density of microprocessor cores that are available on only a single GPU. Whereas high end servers feature up to 24 Intel or AMD CPU cores, the latest GPU offerings from nVidia feature over 2600 cores. Each compute node may be outfitted with up to 4 GPU devices. Success on GPUs varies across problems. However, epistasis screens fare well due to the high degree of parallelism exposed in these problems. Papers that we review routinely report GPU speedups of over two orders of magnitude (>100x) over standard CPU implementations.
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- 2013
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35. Precise inference of copy number alterations in tumor samples from SNP arrays.
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Chen GK, Chang X, Curtis C, and Wang K
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- Aneuploidy, Breast Neoplasms pathology, Cell Line, Tumor, Chromosome Aberrations, Female, Genomics, Genotype, Humans, Likelihood Functions, Markov Chains, Oligonucleotide Array Sequence Analysis, Software, Stromal Cells metabolism, Stromal Cells pathology, Breast Neoplasms genetics, Computational Biology, DNA Copy Number Variations genetics, Genome, Human, Polymorphism, Single Nucleotide genetics
- Abstract
Motivation: The accurate detection of copy number alterations (CNAs) in human genomes is important for understanding susceptibility to cancer and mechanisms of tumor progression. CNA detection in tumors from single nucleotide polymorphism (SNP) genotyping arrays is a challenging problem due to phenomena such as aneuploidy, stromal contamination, genomic waves and intra-tumor heterogeneity, issues that leading methods do not optimally address., Results: Here we introduce methods and software (PennCNV-tumor) for fast and accurate CNA detection using signal intensity data from SNP genotyping arrays. We estimate stromal contamination by applying a maximum likelihood approach over multiple discrete genomic intervals. By conditioning on signal intensity across the genome, our method accounts for both aneuploidy and genomic waves. Finally, our method uses a hidden Markov model to integrate multiple sources of information, including total and allele-specific signal intensity at each SNP, as well as physical maps to make posterior inferences of CNAs. Using real data from cancer cell-lines and patient tumors, we demonstrate substantial improvements in accuracy and computational efficiency compared with existing methods.
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- 2013
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36. Analysis of Latino populations from GALA and MEC studies reveals genomic loci with biased local ancestry estimation.
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Pasaniuc B, Sankararaman S, Torgerson DG, Gignoux C, Zaitlen N, Eng C, Rodriguez-Cintron W, Chapela R, Ford JG, Avila PC, Rodriguez-Santana J, Chen GK, Le Marchand L, Henderson B, Reich D, Haiman CA, Gonzàlez Burchard E, and Halperin E
- Subjects
- Bias, Cohort Studies, Family, Genetic Loci, Genetics, Population methods, Genome, Human, Genome-Wide Association Study, Genotype, Haplotypes, Humans, Mexican Americans, Puerto Rico ethnology, United States ethnology, Hispanic or Latino genetics
- Abstract
Motivation: Local ancestry analysis of genotype data from recently admixed populations (e.g. Latinos, African Americans) provides key insights into population history and disease genetics. Although methods for local ancestry inference have been extensively validated in simulations (under many unrealistic assumptions), no empirical study of local ancestry accuracy in Latinos exists to date. Hence, interpreting findings that rely on local ancestry in Latinos is challenging., Results: Here, we use 489 nuclear families from the mainland USA, Puerto Rico and Mexico in conjunction with 3204 unrelated Latinos from the Multiethnic Cohort study to provide the first empirical characterization of local ancestry inference accuracy in Latinos. Our approach for identifying errors does not rely on simulations but on the observation that local ancestry in families follows Mendelian inheritance. We measure the rate of local ancestry assignments that lead to Mendelian inconsistencies in local ancestry in trios (MILANC), which provides a lower bound on errors in the local ancestry estimates. We show that MILANC rates observed in simulations underestimate the rate observed in real data, and that MILANC varies substantially across the genome. Second, across a wide range of methods, we observe that loci with large deviations in local ancestry also show enrichment in MILANC rates. Therefore, local ancestry estimates at such loci should be interpreted with caution. Finally, we reconstruct ancestral haplotype panels to be used as reference panels in local ancestry inference and show that ancestry inference is significantly improved by incoroprating these reference panels., Availability and Implementation: We provide the reconstructed reference panels together with the maps of MILANC rates as a public resource for researchers analyzing local ancestry in Latinos at http://bogdanlab.pathology.ucla.edu, Supplementary Information: Supplementary data are available at Bioinformatics online.
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- 2013
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37. A meta-analysis identifies new loci associated with body mass index in individuals of African ancestry.
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Monda KL, Chen GK, Taylor KC, Palmer C, Edwards TL, Lange LA, Ng MC, Adeyemo AA, Allison MA, Bielak LF, Chen G, Graff M, Irvin MR, Rhie SK, Li G, Liu Y, Liu Y, Lu Y, Nalls MA, Sun YV, Wojczynski MK, Yanek LR, Aldrich MC, Ademola A, Amos CI, Bandera EV, Bock CH, Britton A, Broeckel U, Cai Q, Caporaso NE, Carlson CS, Carpten J, Casey G, Chen WM, Chen F, Chen YD, Chiang CW, Coetzee GA, Demerath E, Deming-Halverson SL, Driver RW, Dubbert P, Feitosa MF, Feng Y, Freedman BI, Gillanders EM, Gottesman O, Guo X, Haritunians T, Harris T, Harris CC, Hennis AJ, Hernandez DG, McNeill LH, Howard TD, Howard BV, Howard VJ, Johnson KC, Kang SJ, Keating BJ, Kolb S, Kuller LH, Kutlar A, Langefeld CD, Lettre G, Lohman K, Lotay V, Lyon H, Manson JE, Maixner W, Meng YA, Monroe KR, Morhason-Bello I, Murphy AB, Mychaleckyj JC, Nadukuru R, Nathanson KL, Nayak U, N'diaye A, Nemesure B, Wu SY, Leske MC, Neslund-Dudas C, Neuhouser M, Nyante S, Ochs-Balcom H, Ogunniyi A, Ogundiran TO, Ojengbede O, Olopade OI, Palmer JR, Ruiz-Narvaez EA, Palmer ND, Press MF, Rampersaud E, Rasmussen-Torvik LJ, Rodriguez-Gil JL, Salako B, Schadt EE, Schwartz AG, Shriner DA, Siscovick D, Smith SB, Wassertheil-Smoller S, Speliotes EK, Spitz MR, Sucheston L, Taylor H, Tayo BO, Tucker MA, Van Den Berg DJ, Edwards DR, Wang Z, Wiencke JK, Winkler TW, Witte JS, Wrensch M, Wu X, Yang JJ, Levin AM, Young TR, Zakai NA, Cushman M, Zanetti KA, Zhao JH, Zhao W, Zheng Y, Zhou J, Ziegler RG, Zmuda JM, Fernandes JK, Gilkeson GS, Kamen DL, Hunt KJ, Spruill IJ, Ambrosone CB, Ambs S, Arnett DK, Atwood L, Becker DM, Berndt SI, Bernstein L, Blot WJ, Borecki IB, Bottinger EP, Bowden DW, Burke G, Chanock SJ, Cooper RS, Ding J, Duggan D, Evans MK, Fox C, Garvey WT, Bradfield JP, Hakonarson H, Grant SF, Hsing A, Chu L, Hu JJ, Huo D, Ingles SA, John EM, Jordan JM, Kabagambe EK, Kardia SL, Kittles RA, Goodman PJ, Klein EA, Kolonel LN, Le Marchand L, Liu S, McKnight B, Millikan RC, Mosley TH, Padhukasahasram B, Williams LK, Patel SR, Peters U, Pettaway CA, Peyser PA, Psaty BM, Redline S, Rotimi CN, Rybicki BA, Sale MM, Schreiner PJ, Signorello LB, Singleton AB, Stanford JL, Strom SS, Thun MJ, Vitolins M, Zheng W, Moore JH, Williams SM, Ketkar S, Zhu X, Zonderman AB, Kooperberg C, Papanicolaou GJ, Henderson BE, Reiner AP, Hirschhorn JN, Loos RJ, North KE, and Haiman CA
- Subjects
- Case-Control Studies, Gene Frequency, Genetic Loci, Genetic Predisposition to Disease, Genome-Wide Association Study, Humans, Linkage Disequilibrium, Obesity ethnology, Polymorphism, Single Nucleotide, Black or African American genetics, Body Mass Index, Obesity genetics
- Abstract
Genome-wide association studies (GWAS) have identified 36 loci associated with body mass index (BMI), predominantly in populations of European ancestry. We conducted a meta-analysis to examine the association of >3.2 million SNPs with BMI in 39,144 men and women of African ancestry and followed up the most significant associations in an additional 32,268 individuals of African ancestry. We identified one new locus at 5q33 (GALNT10, rs7708584, P = 3.4 × 10(-11)) and another at 7p15 when we included data from the GIANT consortium (MIR148A-NFE2L3, rs10261878, P = 1.2 × 10(-10)). We also found suggestive evidence of an association at a third locus at 6q16 in the African-ancestry sample (KLHL32, rs974417, P = 6.9 × 10(-8)). Thirty-two of the 36 previously established BMI variants showed directionally consistent effect estimates in our GWAS (binomial P = 9.7 × 10(-7)), five of which reached genome-wide significance. These findings provide strong support for shared BMI loci across populations, as well as for the utility of studying ancestrally diverse populations.
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- 2013
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38. Genome-wide association studies identify four ER negative-specific breast cancer risk loci.
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Garcia-Closas M, Couch FJ, Lindstrom S, Michailidou K, Schmidt MK, Brook MN, Orr N, Rhie SK, Riboli E, Feigelson HS, Le Marchand L, Buring JE, Eccles D, Miron P, Fasching PA, Brauch H, Chang-Claude J, Carpenter J, Godwin AK, Nevanlinna H, Giles GG, Cox A, Hopper JL, Bolla MK, Wang Q, Dennis J, Dicks E, Howat WJ, Schoof N, Bojesen SE, Lambrechts D, Broeks A, Andrulis IL, Guénel P, Burwinkel B, Sawyer EJ, Hollestelle A, Fletcher O, Winqvist R, Brenner H, Mannermaa A, Hamann U, Meindl A, Lindblom A, Zheng W, Devillee P, Goldberg MS, Lubinski J, Kristensen V, Swerdlow A, Anton-Culver H, Dörk T, Muir K, Matsuo K, Wu AH, Radice P, Teo SH, Shu XO, Blot W, Kang D, Hartman M, Sangrajrang S, Shen CY, Southey MC, Park DJ, Hammet F, Stone J, Veer LJ, Rutgers EJ, Lophatananon A, Stewart-Brown S, Siriwanarangsan P, Peto J, Schrauder MG, Ekici AB, Beckmann MW, Dos Santos Silva I, Johnson N, Warren H, Tomlinson I, Kerin MJ, Miller N, Marme F, Schneeweiss A, Sohn C, Truong T, Laurent-Puig P, Kerbrat P, Nordestgaard BG, Nielsen SF, Flyger H, Milne RL, Perez JI, Menéndez P, Müller H, Arndt V, Stegmaier C, Lichtner P, Lochmann M, Justenhoven C, Ko YD, Muranen TA, Aittomäki K, Blomqvist C, Greco D, Heikkinen T, Ito H, Iwata H, Yatabe Y, Antonenkova NN, Margolin S, Kataja V, Kosma VM, Hartikainen JM, Balleine R, Tseng CC, Berg DV, Stram DO, Neven P, Dieudonné AS, Leunen K, Rudolph A, Nickels S, Flesch-Janys D, Peterlongo P, Peissel B, Bernard L, Olson JE, Wang X, Stevens K, Severi G, Baglietto L, McLean C, Coetzee GA, Feng Y, Henderson BE, Schumacher F, Bogdanova NV, Labrèche F, Dumont M, Yip CH, Taib NA, Cheng CY, Shrubsole M, Long J, Pylkäs K, Jukkola-Vuorinen A, Kauppila S, Knight JA, Glendon G, Mulligan AM, Tollenaar RA, Seynaeve CM, Kriege M, Hooning MJ, van den Ouweland AM, van Deurzen CH, Lu W, Gao YT, Cai H, Balasubramanian SP, Cross SS, Reed MW, Signorello L, Cai Q, Shah M, Miao H, Chan CW, Chia KS, Jakubowska A, Jaworska K, Durda K, Hsiung CN, Wu PE, Yu JC, Ashworth A, Jones M, Tessier DC, González-Neira A, Pita G, Alonso MR, Vincent D, Bacot F, Ambrosone CB, Bandera EV, John EM, Chen GK, Hu JJ, Rodriguez-Gil JL, Bernstein L, Press MF, Ziegler RG, Millikan RM, Deming-Halverson SL, Nyante S, Ingles SA, Waisfisz Q, Tsimiklis H, Makalic E, Schmidt D, Bui M, Gibson L, Müller-Myhsok B, Schmutzler RK, Hein R, Dahmen N, Beckmann L, Aaltonen K, Czene K, Irwanto A, Liu J, Turnbull C, Rahman N, Meijers-Heijboer H, Uitterlinden AG, Rivadeneira F, Olswold C, Slager S, Pilarski R, Ademuyiwa F, Konstantopoulou I, Martin NG, Montgomery GW, Slamon DJ, Rauh C, Lux MP, Jud SM, Bruning T, Weaver J, Sharma P, Pathak H, Tapper W, Gerty S, Durcan L, Trichopoulos D, Tumino R, Peeters PH, Kaaks R, Campa D, Canzian F, Weiderpass E, Johansson M, Khaw KT, Travis R, Clavel-Chapelon F, Kolonel LN, Chen C, Beck A, Hankinson SE, Berg CD, Hoover RN, Lissowska J, Figueroa JD, Chasman DI, Gaudet MM, Diver WR, Willett WC, Hunter DJ, Simard J, Benitez J, Dunning AM, Sherman ME, Chenevix-Trench G, Chanock SJ, Hall P, Pharoah PD, Vachon C, Easton DF, Haiman CA, and Kraft P
- Subjects
- Breast Neoplasms metabolism, Breast Neoplasms pathology, Case-Control Studies, Cooperative Behavior, Female, Genome-Wide Association Study, Genotype, Humans, Meta-Analysis as Topic, Oligonucleotide Array Sequence Analysis, Receptors, Estrogen genetics, Risk Factors, Breast Neoplasms etiology, Genetic Loci genetics, Genetic Predisposition to Disease, Polymorphism, Single Nucleotide genetics, Receptors, Estrogen metabolism
- Abstract
Estrogen receptor (ER)-negative tumors represent 20-30% of all breast cancers, with a higher proportion occurring in younger women and women of African ancestry. The etiology and clinical behavior of ER-negative tumors are different from those of tumors expressing ER (ER positive), including differences in genetic predisposition. To identify susceptibility loci specific to ER-negative disease, we combined in a meta-analysis 3 genome-wide association studies of 4,193 ER-negative breast cancer cases and 35,194 controls with a series of 40 follow-up studies (6,514 cases and 41,455 controls), genotyped using a custom Illumina array, iCOGS, developed by the Collaborative Oncological Gene-environment Study (COGS). SNPs at four loci, 1q32.1 (MDM4, P = 2.1 × 10(-12) and LGR6, P = 1.4 × 10(-8)), 2p24.1 (P = 4.6 × 10(-8)) and 16q12.2 (FTO, P = 4.0 × 10(-8)), were associated with ER-negative but not ER-positive breast cancer (P > 0.05). These findings provide further evidence for distinct etiological pathways associated with invasive ER-positive and ER-negative breast cancers.
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- 2013
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39. Genotype imputation via matrix completion.
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Chi EC, Zhou H, Chen GK, Del Vecchyo DO, and Lange K
- Subjects
- Algorithms, Computer Simulation, Genome, Human, HapMap Project, Humans, Microarray Analysis, Polymorphism, Single Nucleotide, Artificial Intelligence, Genotype, Models, Genetic, Software
- Abstract
Most current genotype imputation methods are model-based and computationally intensive, taking days to impute one chromosome pair on 1000 people. We describe an efficient genotype imputation method based on matrix completion. Our matrix completion method is implemented in MATLAB and tested on real data from HapMap 3, simulated pedigree data, and simulated low-coverage sequencing data derived from the 1000 Genomes Project. Compared with leading imputation programs, the matrix completion algorithm embodied in our program MENDEL-IMPUTE achieves comparable imputation accuracy while reducing run times significantly. Implementation in a lower-level language such as Fortran or C is apt to further improve computational efficiency.
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- 2013
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40. A genome-wide association study of breast cancer in women of African ancestry.
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Chen F, Chen GK, Stram DO, Millikan RC, Ambrosone CB, John EM, Bernstein L, Zheng W, Palmer JR, Hu JJ, Rebbeck TR, Ziegler RG, Nyante S, Bandera EV, Ingles SA, Press MF, Ruiz-Narvaez EA, Deming SL, Rodriguez-Gil JL, Demichele A, Chanock SJ, Blot W, Signorello L, Cai Q, Li G, Long J, Huo D, Zheng Y, Cox NJ, Olopade OI, Ogundiran TO, Adebamowo C, Nathanson KL, Domchek SM, Simon MS, Hennis A, Nemesure B, Wu SY, Leske MC, Ambs S, Hutter CM, Young A, Kooperberg C, Peters U, Rhie SK, Wan P, Sheng X, Pooler LC, Van Den Berg DJ, Le Marchand L, Kolonel LN, Henderson BE, and Haiman CA
- Subjects
- Adult, Aged, Aged, 80 and over, Case-Control Studies, Cohort Studies, Female, Genetic Predisposition to Disease, Genome-Wide Association Study, Humans, Middle Aged, Risk Factors, Young Adult, Black or African American genetics, Black People genetics, Breast Neoplasms genetics, Polymorphism, Single Nucleotide
- Abstract
Genome-wide association studies (GWAS) in diverse populations are needed to reveal variants that are more common and/or limited to defined populations. We conducted a GWAS of breast cancer in women of African ancestry, with genotyping of >1,000,000 SNPs in 3,153 African American cases and 2,831 controls, and replication testing of the top 66 associations in an additional 3,607 breast cancer cases and 11,330 controls of African ancestry. Two of the 66 SNPs replicated (p < 0.05) in stage 2, which reached statistical significance levels of 10(-6) and 10(-5) in the stage 1 and 2 combined analysis (rs4322600 at chromosome 14q31: OR = 1.18, p = 4.3 × 10(-6); rs10510333 at chromosome 3p26: OR = 1.15, p = 1.5 × 10(-5)). These suggestive risk loci have not been identified in previous GWAS in other populations and will need to be examined in additional samples. Identification of novel risk variants for breast cancer in women of African ancestry will demand testing of a substantially larger set of markers from stage 1 in a larger replication sample.
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- 2013
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41. A genome-wide scan for breast cancer risk haplotypes among African American women.
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Song C, Chen GK, Millikan RC, Ambrosone CB, John EM, Bernstein L, Zheng W, Hu JJ, Ziegler RG, Nyante S, Bandera EV, Ingles SA, Press MF, Deming SL, Rodriguez-Gil JL, Chanock SJ, Wan P, Sheng X, Pooler LC, Van Den Berg DJ, Le Marchand L, Kolonel LN, Henderson BE, Haiman CA, and Stram DO
- Subjects
- Breast Neoplasms ethnology, Female, Humans, United States, Black or African American, Black People, Breast Neoplasms genetics, Genome-Wide Association Study, Haplotypes
- Abstract
Genome-wide association studies (GWAS) simultaneously investigating hundreds of thousands of single nucleotide polymorphisms (SNP) have become a powerful tool in the investigation of new disease susceptibility loci. Haplotypes are sometimes thought to be superior to SNPs and are promising in genetic association analyses. The application of genome-wide haplotype analysis, however, is hindered by the complexity of haplotypes themselves and sophistication in computation. We systematically analyzed the haplotype effects for breast cancer risk among 5,761 African American women (3,016 cases and 2,745 controls) using a sliding window approach on the genome-wide scale. Three regions on chromosomes 1, 4 and 18 exhibited moderate haplotype effects. Furthermore, among 21 breast cancer susceptibility loci previously established in European populations, 10p15 and 14q24 are likely to harbor novel haplotype effects. We also proposed a heuristic of determining the significance level and the effective number of independent tests by the permutation analysis on chromosome 22 data. It suggests that the effective number was approximately half of the total (7,794 out of 15,645), thus the half number could serve as a quick reference to evaluating genome-wide significance if a similar sliding window approach of haplotype analysis is adopted in similar populations using similar genotype density.
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- 2013
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42. A meta-analysis of genome-wide association studies of breast cancer identifies two novel susceptibility loci at 6q14 and 20q11.
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Siddiq A, Couch FJ, Chen GK, Lindström S, Eccles D, Millikan RC, Michailidou K, Stram DO, Beckmann L, Rhie SK, Ambrosone CB, Aittomäki K, Amiano P, Apicella C, Baglietto L, Bandera EV, Beckmann MW, Berg CD, Bernstein L, Blomqvist C, Brauch H, Brinton L, Bui QM, Buring JE, Buys SS, Campa D, Carpenter JE, Chasman DI, Chang-Claude J, Chen C, Clavel-Chapelon F, Cox A, Cross SS, Czene K, Deming SL, Diasio RB, Diver WR, Dunning AM, Durcan L, Ekici AB, Fasching PA, Feigelson HS, Fejerman L, Figueroa JD, Fletcher O, Flesch-Janys D, Gaudet MM, Gerty SM, Rodriguez-Gil JL, Giles GG, van Gils CH, Godwin AK, Graham N, Greco D, Hall P, Hankinson SE, Hartmann A, Hein R, Heinz J, Hoover RN, Hopper JL, Hu JJ, Huntsman S, Ingles SA, Irwanto A, Isaacs C, Jacobs KB, John EM, Justenhoven C, Kaaks R, Kolonel LN, Coetzee GA, Lathrop M, Le Marchand L, Lee AM, Lee IM, Lesnick T, Lichtner P, Liu J, Lund E, Makalic E, Martin NG, McLean CA, Meijers-Heijboer H, Meindl A, Miron P, Monroe KR, Montgomery GW, Müller-Myhsok B, Nickels S, Nyante SJ, Olswold C, Overvad K, Palli D, Park DJ, Palmer JR, Pathak H, Peto J, Pharoah P, Rahman N, Rivadeneira F, Schmidt DF, Schmutzler RK, Slager S, Southey MC, Stevens KN, Sinn HP, Press MF, Ross E, Riboli E, Ridker PM, Schumacher FR, Severi G, Dos Santos Silva I, Stone J, Sund M, Tapper WJ, Thun MJ, Travis RC, Turnbull C, Uitterlinden AG, Waisfisz Q, Wang X, Wang Z, Weaver J, Schulz-Wendtland R, Wilkens LR, Van Den Berg D, Zheng W, Ziegler RG, Ziv E, Nevanlinna H, Easton DF, Hunter DJ, Henderson BE, Chanock SJ, Garcia-Closas M, Kraft P, Haiman CA, and Vachon CM
- Subjects
- Female, Humans, Polymorphism, Single Nucleotide genetics, Receptors, Estrogen genetics, Breast Neoplasms genetics, Genetic Predisposition to Disease genetics, Genome-Wide Association Study
- Abstract
Genome-wide association studies (GWAS) of breast cancer defined by hormone receptor status have revealed loci contributing to susceptibility of estrogen receptor (ER)-negative subtypes. To identify additional genetic variants for ER-negative breast cancer, we conducted the largest meta-analysis of ER-negative disease to date, comprising 4754 ER-negative cases and 31 663 controls from three GWAS: NCI Breast and Prostate Cancer Cohort Consortium (BPC3) (2188 ER-negative cases; 25 519 controls of European ancestry), Triple Negative Breast Cancer Consortium (TNBCC) (1562 triple negative cases; 3399 controls of European ancestry) and African American Breast Cancer Consortium (AABC) (1004 ER-negative cases; 2745 controls). We performed in silico replication of 86 SNPs at P ≤ 1 × 10(-5) in an additional 11 209 breast cancer cases (946 with ER-negative disease) and 16 057 controls of Japanese, Latino and European ancestry. We identified two novel loci for breast cancer at 20q11 and 6q14. SNP rs2284378 at 20q11 was associated with ER-negative breast cancer (combined two-stage OR = 1.16; P = 1.1 × 10(-8)) but showed a weaker association with overall breast cancer (OR = 1.08, P = 1.3 × 10(-6)) based on 17 869 cases and 43 745 controls and no association with ER-positive disease (OR = 1.01, P = 0.67) based on 9965 cases and 22 902 controls. Similarly, rs17530068 at 6q14 was associated with breast cancer (OR = 1.12; P = 1.1 × 10(-9)), and with both ER-positive (OR = 1.09; P = 1.5 × 10(-5)) and ER-negative (OR = 1.16, P = 2.5 × 10(-7)) disease. We also confirmed three known loci associated with ER-negative (19p13) and both ER-negative and ER-positive breast cancer (6q25 and 12p11). Our results highlight the value of large-scale collaborative studies to identify novel breast cancer risk loci.
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- 2012
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43. Mendel-GPU: haplotyping and genotype imputation on graphics processing units.
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Chen GK, Wang K, Stram AH, Sobel EM, and Lange K
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- Genome, Human, Genome-Wide Association Study, Haplotypes, High-Throughput Nucleotide Sequencing, Humans, Polymorphism, Single Nucleotide, Sequence Analysis, DNA, Algorithms, Genotype, Software
- Abstract
Motivation: In modern sequencing studies, one can improve the confidence of genotype calls by phasing haplotypes using information from an external reference panel of fully typed unrelated individuals. However, the computational demands are so high that they prohibit researchers with limited computational resources from haplotyping large-scale sequence data., Results: Our graphics processing unit based software delivers haplotyping and imputation accuracies comparable to competing programs at a fraction of the computational cost and peak memory demand., Availability: Mendel-GPU, our OpenCL software, runs on Linux platforms and is portable across AMD and nVidia GPUs. Users can download both code and documentation at http://code.google.com/p/mendel-gpu/., Contact: gary.k.chen@usc.edu., Supplementary Information: Supplementary data are available at Bioinformatics online.
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- 2012
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44. Evaluating genetic risk for prostate cancer among Japanese and Latinos.
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Cheng I, Chen GK, Nakagawa H, He J, Wan P, Laurie CC, Shen J, Sheng X, Pooler LC, Crenshaw AT, Mirel DB, Takahashi A, Kubo M, Nakamura Y, Al Olama AA, Benlloch S, Donovan JL, Guy M, Hamdy FC, Kote-Jarai Z, Neal DE, Wilkens LR, Monroe KR, Stram DO, Muir K, Eeles RA, Easton DF, Kolonel LN, Henderson BE, Le Marchand L, and Haiman CA
- Subjects
- California epidemiology, Cohort Studies, Genetic Predisposition to Disease, Genome-Wide Association Study, Genotype, Hawaii epidemiology, Humans, Japan ethnology, Male, Models, Statistical, Neoplasm Staging, Polymorphism, Single Nucleotide, Prostatic Neoplasms epidemiology, Prostatic Neoplasms pathology, Risk, SEER Program, Asian People genetics, Hispanic or Latino genetics, Prostatic Neoplasms ethnology, Prostatic Neoplasms genetics
- Abstract
Background: There have been few genome-wide association studies (GWAS) of prostate cancer among diverse populations. To search for novel prostate cancer risk variants, we conducted GWAS of prostate cancer in Japanese and Latinos. In addition, we tested prostate cancer risk variants and developed genetic risk models of prostate cancer for Japanese and Latinos., Methods: Our first-stage GWAS of prostate cancer included Japanese (cases/controls = 1,033/1,042) and Latino (cases/controls = 1,043/1,057) from the Multiethnic Cohort (MEC). Significant associations from stage I (P < 1.0 × 10(-4)) were examined in silico in GWAS of prostate cancer (stage II) in Japanese (cases/controls = 1,583/3,386) and Europeans (cases/controls = 1,854/1,894)., Results: No novel stage I single-nucleotide polymorphism (SNP) outside of known risk regions reached genome-wide significance. For Japanese, in stage I, the most notable putative novel association was seen with 10 SNPs (P ≤ 8.0 × 10(-6)) at chromosome 2q33; however, this was not replicated in stage II. For Latinos, the most significant association was observed with rs17023900 at the known 3p12 risk locus (stage I: OR = 1.45; P = 7.01 × 10(-5) and stage II: OR = 1.58; P = 3.05 × 10(-7)). The majority of the established risk variants for prostate cancer, 79% and 88%, were positively associated with prostate cancer in Japanese and Latinos (stage I), respectively. The cumulative effects of these variants significantly influence prostate cancer risk (OR per allele = 1.10; P = 2.71 × 10(-25) and OR = 1.07; P = 1.02 × 10(-16) for Japanese and Latinos, respectively)., Conclusion and Impact: Our GWAS of prostate cancer did not identify novel genome-wide significant variants. However, our findings show that established risk variants for prostate cancer significantly contribute to risk among Japanese and Latinos., (©2012 AACR.)
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- 2012
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45. Construction of Escherichia coli strains producing L-serine from glucose.
- Author
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Li Y, Chen GK, Tong XW, Zhang HT, Liu XG, Liu YH, and Lu FP
- Subjects
- Escherichia coli enzymology, Escherichia coli metabolism, Escherichia coli Proteins metabolism, Gene Knockout Techniques, L-Serine Dehydratase metabolism, Mutagenesis, Site-Directed, Phosphoglycerate Dehydrogenase metabolism, Escherichia coli genetics, Genetic Engineering methods, Glucose metabolism, Serine metabolism
- Abstract
L-Serine is usually produced from glycine. We have genetically engineered Escherichia coli to produce L-serine from glucose intracellularly. D-3-Phosphoglycerate dehydrogenase (PGDH, EC 1.1.1.95) in E. coli catalyzes the first committed step in L-serine formation but is inhibited by L-serine. To overcome this feedback inhibition, both the His(344) and Asn(346) residues of PGDH were converted to alanine and the mutated PGDH (PGDH(dr)) became insensitive to L-serine. However, overexpression of PGDH(dr) gave no significant increase of L-serine accumulation but, when L-serine deaminase genes (sdaA, sdaB and tdcG) were deleted, serine accumulated: (1) deletion of sdaA gave up to 0.03 mmol L-serine/g; (2) deletion of both sdaA and sdaB accumulated L-serine up to 0.09 mmol/g; and (3) deletion of sdaA, sdaB and tdcG gave up to 0.13 mmol L-serine/g cell dry wt.
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- 2012
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46. A scalable and portable framework for massively parallel variable selection in genetic association studies.
- Author
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Chen GK
- Subjects
- Humans, Male, Polymorphism, Single Nucleotide, Programming Languages, Prostatic Neoplasms ethnology, Prostatic Neoplasms genetics, Algorithms, Genome-Wide Association Study, Software
- Abstract
Unlabelled: The deluge of data emerging from high-throughput sequencing technologies poses large analytical challenges when testing for association to disease. We introduce a scalable framework for variable selection, implemented in C++ and OpenCL, that fits regularized regression across multiple Graphics Processing Units. Open source code and documentation can be found at a Google Code repository under the URL http://bioinformatics.oxfordjournals.org/content/early/2012/01/10/bioinformatics.bts015.abstract., Supplementary Information: Supplementary data are available at Bioinformatics online.
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- 2012
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47. Common variants at 11q12, 10q26 and 3p11.2 are associated with prostate cancer susceptibility in Japanese.
- Author
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Akamatsu S, Takata R, Haiman CA, Takahashi A, Inoue T, Kubo M, Furihata M, Kamatani N, Inazawa J, Chen GK, Le Marchand L, Kolonel LN, Katoh T, Yamano Y, Yamakado M, Takahashi H, Yamada H, Egawa S, Fujioka T, Henderson BE, Habuchi T, Ogawa O, Nakamura Y, and Nakagawa H
- Subjects
- Aged, Aged, 80 and over, Base Sequence, Cell Line, Genetic Variation, Genome-Wide Association Study, Genotype, Humans, Japan, Linkage Disequilibrium, Male, Middle Aged, RNA Interference, RNA, Small Interfering, Sequence Analysis, DNA, Chromosomes, Human, Pair 10 genetics, Chromosomes, Human, Pair 11 genetics, Chromosomes, Human, Pair 3 genetics, Genetic Predisposition to Disease, Polymorphism, Single Nucleotide genetics, Prostatic Neoplasms genetics
- Abstract
We have previously reported multiple loci associated with prostate cancer susceptibility in a Japanese population using a genome-wide association study (GWAS). To identify additional prostate cancer susceptibility loci, we genotyped nine SNPs that were nominally associated with prostate cancer (P < 1 × 10(-4)) in our previous GWAS in three independent studies of prostate cancer in Japanese men (2,557 individuals with prostate cancer (cases) and 3,003 controls). In a meta-analysis of our previous GWAS and the replication studies, which included a total of 7,141 prostate cancer cases and 11,804 controls from a single ancestry group, three new loci reached genome-wide significance on chromosomes 11q12 (rs1938781; P = 1.10 × 10(-10); FAM111A-FAM111B), 10q26 (rs2252004; P = 1.98 × 10(-8)) and 3p11.2 (rs2055109; P = 3.94 × 10(-8)). We also found suggestive evidence of association at a previously reported prostate cancer susceptibility locus at 2p11 (rs2028898; P = 1.08 × 10(-7)). The identification of three new susceptibility loci should provide additional insight into the pathogenesis of prostate cancer and emphasizes the importance of conducting GWAS in diverse populations.
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- 2012
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48. Meta-analysis identifies common variants associated with body mass index in east Asians.
- Author
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Wen W, Cho YS, Zheng W, Dorajoo R, Kato N, Qi L, Chen CH, Delahanty RJ, Okada Y, Tabara Y, Gu D, Zhu D, Haiman CA, Mo Z, Gao YT, Saw SM, Go MJ, Takeuchi F, Chang LC, Kokubo Y, Liang J, Hao M, Le Marchand L, Zhang Y, Hu Y, Wong TY, Long J, Han BG, Kubo M, Yamamoto K, Su MH, Miki T, Henderson BE, Song H, Tan A, He J, Ng DP, Cai Q, Tsunoda T, Tsai FJ, Iwai N, Chen GK, Shi J, Xu J, Sim X, Xiang YB, Maeda S, Ong RT, Li C, Nakamura Y, Aung T, Kamatani N, Liu JJ, Lu W, Yokota M, Seielstad M, Fann CS, Wu JY, Lee JY, Hu FB, Tanaka T, Tai ES, and Shu XO
- Subjects
- Asia, Eastern, Genome-Wide Association Study, Genotype, Humans, Polymorphism, Single Nucleotide genetics, Asian People genetics, Body Mass Index, Genetic Predisposition to Disease genetics, Obesity genetics, Quantitative Trait Loci genetics
- Abstract
Multiple genetic loci associated with obesity or body mass index (BMI) have been identified through genome-wide association studies conducted predominantly in populations of European ancestry. We performed a meta-analysis of associations between BMI and approximately 2.4 million SNPs in 27,715 east Asians, which was followed by in silico and de novo replication studies in 37,691 and 17,642 additional east Asians, respectively. We identified ten BMI-associated loci at genome-wide significance (P < 5.0 × 10(-8)), including seven previously identified loci (FTO, SEC16B, MC4R, GIPR-QPCTL, ADCY3-DNAJC27, BDNF and MAP2K5) and three novel loci in or near the CDKAL1, PCSK1 and GP2 genes. Three additional loci nearly reached the genome-wide significance threshold, including two previously identified loci in the GNPDA2 and TFAP2B genes and a newly identified signal near PAX6, all of which were associated with BMI with P < 5.0 × 10(-7). Findings from this study may shed light on new pathways involved in obesity and demonstrate the value of conducting genetic studies in non-European populations.
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- 2012
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49. Population genetic structure and origins of Native Hawaiians in the multiethnic cohort study.
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Kim SK, Gignoux CR, Wall JD, Lum-Jones A, Wang H, Haiman CA, Chen GK, Henderson BE, Kolonel LN, Le Marchand L, Stram DO, Saxena R, and Cheng I
- Subjects
- Bayes Theorem, Cluster Analysis, Cohort Studies, Female, Gene Frequency, Genome, Human, Genome, Mitochondrial, Hawaii, Human Migration, Humans, Male, Models, Genetic, Polymorphism, Single Nucleotide, Native Hawaiian or Other Pacific Islander genetics, Population Growth
- Abstract
The population genetic structure of Native Hawaiians has yet to be comprehensively studied, and the ancestral origins of Polynesians remain in question. In this study, we utilized high-resolution genome-wide SNP data and mitochondrial genomes of 148 and 160 Native Hawaiians, respectively, to characterize their population structure of the nuclear and mitochondrial genomes, ancestral origins, and population expansion. Native Hawaiians, who self-reported full Native Hawaiian heritage, demonstrated 78% Native Hawaiian, 11.5% European, and 7.8% Asian ancestry with 99% belonging to the B4 mitochondrial haplogroup. The estimated proportions of Native Hawaiian ancestry for those who reported mixed ancestry (i.e. 75% and 50% Native Hawaiian heritage) were found to be consistent with their self-reported heritage. A significant proportion of Melanesian ancestry (mean = 32%) was estimated in 100% self-reported Native Hawaiians in an ADMIXTURE analysis of Asian, Melanesian, and Native Hawaiian populations of K = 2, where K denotes the number of ancestral populations. This notable proportion of Melanesian admixture supports the "Slow-Boat" model of migration of ancestral Polynesian populations from East Asia to the Pacific Islands. In addition, approximately 1,300 years ago a single, strong expansion of the Native Hawaiian population was estimated. By providing important insight into the underlying population structure of Native Hawaiians, this study lays the foundation for future genetic association studies of this U.S. minority population.
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- 2012
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50. Copy number alterations in prostate tumors and disease aggressiveness.
- Author
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Cheng I, Levin AM, Tai YC, Plummer S, Chen GK, Neslund-Dudas C, Casey G, Rybicki BA, and Witte JS
- Subjects
- Aged, Disease Progression, Genome, Human, Humans, Male, Middle Aged, Neoplasm Grading, Neoplasm Staging, Oligonucleotide Array Sequence Analysis, Polymorphism, Single Nucleotide, Prostatic Neoplasms pathology, Signal Transduction, DNA Copy Number Variations, Prostatic Neoplasms genetics
- Abstract
Detecting genomic alterations that result in more aggressive prostate cancer may improve clinical treatment and our understanding of the biology underlying this common but complex disease. To this end, we undertook a genome-wide copy number alterations (CNAs) study of clinicopathological characteristics of 62 prostate tumors using the Illumina 1M single nucleotide polymorphism array. The highest overall frequencies of CNAs were on chromosomes 8q (gains), 8p (loss and copy-neutral), and 6q (copy-loss). Combined loss and copy-neutral events were associated with increasing disease grade (P = 0.03), stage (P = 0.01), and diagnostic prostate specific antigen (PSA) (P = 0.01). Further evaluation of CNAs using gene ontology identified pathways involved with disease aggressiveness. The "regulation of apoptosis" pathway was associated with stage of disease (P = 0.004), while the "reproductive cellular process" pathway was associated with diagnostic PSA (P = 0.00038). Specific genes within these pathways exhibited strong associations with clinical characteristics; for example, in the apoptosis pathway BNIP3L was associated with increasing prostate tumor stage (P = 0.007). These findings confirm known regions of CNAs in prostate cancer and localize additional regions and possible genes (e.g., BNIP3L, WWOX, and GATM) that may help to clarify the genetic basis of prostate cancer aggressiveness., (Copyright © 2011 Wiley Periodicals, Inc.)
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- 2012
- Full Text
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