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Background: Genome-wide association studies (GWAS) have identified dozens of single nucleotide polymorphisms (SNPs) associated with type 2 diabetes risk. We have previously confirmed the associations of genetic variants in HHEX, CDKAL1, VEGFA and FTO with type 2 diabetes in Han Chinese. However, the cumulative effect and predictive value of these GWAS identified SNPs on the risk of type 2 diabetes in Han Chinese are largely unknown. Methodology/Principal Findings: We conducted a two-stage case-control study consisting of 2,925 cases and 3,281controls to examine the association of 30 SNPs identified by GWAS with type 2 diabetes in Han Chinese. Significant associations were found for proxy SNPs at KCNQ1 [odds ratio (OR) = 1.41, P = 9.91 × 10–16 for rs2237897], CDKN2A/CDKN2B (OR = 1.30, P = 1.34 × 10–10 for rs10811661), CENTD2 (OR = 1.28, P = 9.88 × 10-4 for rs1552224) and SLC30A8 (OR = 1.19, P = 1.43 × 10-5 for rs13266634). We further evaluated the cumulative effect on type 2 diabetes of these 4 SNPs, in combination with 5 SNPs at HHEX, CDKAL1, VEGFA and FTO reported previously. Individuals carrying 12 or more risk alleles had a nearly 4-fold increased risk for developing type 2 diabetes compared with those carrying less than 6 risk alleles [adjusted OR = 3.68, 95% confidence interval (CI): 2.76–4.91]. Adding the genetic factors to clinical factors slightly improved the prediction of type 2 diabetes, with the area under the receiver operating characteristic curve increasing from 0.76 to 0.78. However, the difference was statistically significant (P < 0.0001). Conclusions/Significance: We confirmed associations of SNPs in KCNQ1, CDKN2A/CDKN2B, CENTD2 and SLC30A8 with type 2 diabetes in Han Chinese. The utilization of genetic information may improve the accuracy of risk prediction in combination with clinical characteristics for type 2 diabetes. [ABSTRACT FROM AUTHOR]

Cyclooxygenase-2 (COX-2) involves in multiple processes in carcinogenesis, including inflammation, apoptosis inhibition, immune response suppression, tumor cell invasion, and angiogenesis. COX-2 is overexpressed in various cancers, including gastric cancer. COX-2 is encoded by prostaglandin endoperoxide synthase 2 ( PTGS2) gene. We hypothesized that potentially functional polymorphisms in PTGS2 may contribute to gastric cancer risk. To assess this hypothesis, we conducted a case-control study with 1681 gastric cancer cases and 1916 control subjects in a Chinese population to evaluate the association between a polymorphism in 3′-untranslated region of PTGS2, rs5275, and the risk of gastric cancer. Logistic regression analysis revealed that variant allele (C) of rs5275 was significantly associated with an increased risk of gastric cancer (per allele odds ratio [OR]=1.14, 95% confidence interval [CI]=1.01-1.29, p=0.030). This association was more prominent in females (per allele OR=1.42, 95% CI=1.11-1.81, p=0.005) and nonsmokers (per allele OR=1.35, 95% CI=1.14-1.59, p=0.001). Interestingly, we detected a negative interaction between rs5275 and smoking on the gastric cancer risk ( p=0.007). Our findings indicate that PTGS2 rs5275T/C may be a candidate genetic marker for gastric cancer susceptibility. [ABSTRACT FROM AUTHOR]

A single nucleotide polymorphism (SNP) rs999737 at 14q24.1 was identified as a susceptibility marker of breast cancer in a genome-wide association study of the European population, which was also confirmed by some of the following studies in populations of European descent. However, rs999737 is very rare or nonpolymorphic in non-Europeans including Chinese, and the role of other genetic variants at 14q24.1 has not been evaluated in populations of non-European descent. In this study, we first selected 21 common tagging SNPs (minor allele frequency [MAF] >0.05 in the Chinese population) by searching the Hapmap database, covering a linage disequilibrium region of more than 70 Kb at 14q24.1, and then conducted a two-stage study (stage I: 878 cases and 900 controls; stage II: 914 cases and 967 controls) to investigate the associations between these tagging SNPs and risk of breast cancer in a Chinese population. In stage I, two SNPs (rs2842346 and rs17828907) were identified to be significantly associated with breast cancer risk ( p=0.030 and 0.027 for genotype distributions, respectively). However, no significant associations were found between these two SNPs and breast cancer risk in either stage II or the combined dataset. These findings suggest that common variants at 14q24.1 might not be associated with the risk of breast cancer in the Chinese population, which will need the replication in additional larger studies. [ABSTRACT FROM AUTHOR]

Recent genome-wide association studies have identified several single nucleotide polymorphisms (SNPs) on chromosome 6p21.1 and 6p22.3 as type 2 diabetes (T2D) susceptibility loci in the European and Japanese populations. However, these SNPs have not been well evaluated in Chinese population. Here, we performed a case-control study with 2925 T2D cases and 3281 controls in a Chinese population. We used TaqMan OpenArray and Sequenom MassARRAY to genotype the four SNPs (rs4712523, rs7756992, rs4712524 and rs6931514) in CDKAL1 (cyclin-dependent kinase 5 regulatory subunit-associated protein 1-like 1) at 6p22.3 and one SNP (rs9472138) near vascular endothelial growth factor A (VEGFA) at 6p21.1. All the five SNPs were significantly associated with T2D risk with overall effects (odds ratio, OR) from 1.19 to 1.29 in the additive genetic model (rs6931514: OR=1.29, 95% confidence intervals (95% CI)=1.19-1.39, P=5.6 × 10−10; rs7756992: OR=1.23, 95% CI=1.15-1.32, P=1.2 × 10−8; rs4712523: OR=1.25, 95% CI=1.15-1.35, P=3.8 × 10−8; rs4712524: OR=1.24, 95% CI=1.15-1.35, P=6.8 × 10−8; rs9472138: OR=1.19, 95% CI=1.05-1.34, P=006). Conditional analysis identified two independent signals (rs6931514 at 6p22.3 and rs9472138 at 6p21.1) that were significantly associated with T2D. Compared with the wild homozygote of rs6931514 and rs9472138, subjects with variant alleles of the two SNPs had increased risk for T2D susceptibility in a dose-response manner (Ptrend=7.4 × 10−12). Our findings indicated that genetic variants of CDKAL1 and VEGFA on chromosome 6 may contribute to T2D risk in Chinese population, especially for rs9472138 at 6p21.1 identified for the first time to significantly increase the T2D risk in Chinese individuals. [ABSTRACT FROM AUTHOR]

Non-obstructive azoospermia (NOA) is one of the most severe forms of male infertility. Its pathophysiology is largely unknown, and few genetic influences have been defined. To identify common variants contributing to NOA in Han Chinese men, we performed a three-stage genome-wide association study of 2,927 individuals with NOA and 5,734 controls. The combined analyses identified significant (P < 5.0 × 10?8) associations between NOA risk and common variants near PRMT6 (rs12097821 at 1p13.3: odds ratio (OR) = 1.25, P = 5.7 × 10?10), PEX10 (rs2477686 at 1p36.32: OR = 1.39, P = 5.7 × 10?12) and SOX5 (rs10842262 at 12p12.1: OR = 1.23, P = 2.3 × 10?9). These findings implicate genetic variants at 1p13.3, 1p36.32 and 12p12.1 in the etiology of NOA in Han Chinese men. [ABSTRACT FROM AUTHOR]

Two recent genome-wide association studies reported significant associations of genetic variants at 1q22, 10q23 and 20p13 with gastric cancer (GC) risk in Chinese populations. However, these findings have not been confirmed in other independent studies. Here, we performed an independent case–control study in a Chinese population by genotyping three loci (rs4072037A>G at 1q22, rs2274223A>G at 10q23 and rs13042395C>T at 20p13) in 1681 GC cases and 1858 controls. We found that rs4072037 at 1q22 and rs2274223 at 10q23 were significantly associated with risk of GC with per allele odds ratio (OR) of 0.72 [95% confidence interval (CI): 0.63–0.81; P = 2.98 × 10−7] and 1.42 (95% CI: 1.27–1.58; P = 9.68 × 10−10), respectively. The association was more prominent for rs2274223 in female (OR = 1.86, 95% CI: 1.49–2.32) and gastric cardia adenocarcinoma (GCA) (OR = 1.71, 95% CI: 1.49–1.95). Furthermore, we combined the two single-nucleotide polymorphisms to evaluate the joint effect and found that the GC risk significantly increased with the number of risk allele increasing with a trend P value of 6.66 × 10−16, and individuals with four risk alleles had a 3.28-fold (95% CI: 1.75–6.13) risk of GC compared with those having no risk alleles. However, no significant association was detected between rs13042395 at 20p13 and GC risk (OR = 1.04, 95% CI: 0.94–1.15; P = 0.452). In conclusion, our results indicate that genetic variants at 1q22 and 10q23 but not 20p13 may serve as candidate markers for GC susceptibility in the Chinese population. [ABSTRACT FROM AUTHOR]

Cancer susceptibility loci identified in reported genome-wide association studies (GWAS) are often tumor-specific; however, evidence of pleiotropy of some genes/loci has also been observed and biologically plausible. We hypothesized that there are important regions in the genome harboring genetic variants associated with risk of multiple types of cancer. In the current study, we attempted to map genetic variants that have consistent effects on risk of multiple cancers using our existing genome-wide scan data of lung cancer, noncardia gastric cancer, and esophageal squamous-cell carcinoma with overall 5,368 cases and 4,006 controls (GWAS stage), followed by a further evaluation in additional 9,001 cases with one of these cancer types and 11,436 controls (replication stage). Five variants satisfying the criteria of pleiotropy with p values from 1.10 × 10−8 to 8.96 × 10−6 for genome-wide scans of three cancer types were further evaluated in the replication stage. We found consistent associations of rs2494938 at 6p21.1 and rs2285947 at 7p15.3 with these three cancers in both GWAS and replication stages. In combined samples of GWAS and replication stages, the minor alleles of rs2494938 and rs2285947 were significantly associated with an increased risk of the cancers (odds ratio [OR] = 1.15, 95% confidence interval [CI], 1.10–1.19 and OR = 1.17, 95% CI, 1.12–1.21), with the p values being 1.20 × 10−12 and 1.26 × 10−16, respectively, which are at a genome-wide significance level. Our findings highlight the potential importance of variants at 6p21.1 and 7p15.3 in the susceptibility to multiple cancers. [Copyright &y& Elsevier]