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PDF file, 199KB, Supplementary Table 1. TGF-β signaling pathway SNPs and breast cancer risk, Stage I. Supplementary Table 2. TGF-β signaling pathway variants showing an association with breast cancer risk (P value ≤0.05) in at least one genetic model, Stage 1. Supplementary Table 3. Results for TGF-β signaling pathway SNPs selected for Stage II evaluation (not presented in Table 3).

Background: The TGF-β signaling pathway plays a significant role in the carcinogenic process of breast cancer.Methods: We systematically evaluated associations of common variants in TGF-β signaling pathway genes with breast cancer risk using a multistage, case–control study among Asian women.Results: In the first stage, 341 single-nucleotide polymorphisms with minor allele frequencies ≥ 0.05 across 11 genes were evaluated among 2,926 cases and 2,380 controls recruited as a part of the Shanghai Breast Cancer Genetics Study (SBCGS). In the second stage, 20 SNPs with promising associations were evaluated among an additional 1,890 cases and 2,000 controls from the SBCGS. One variant, TGFBR2 rs1078985, had highly consistent and significant associations with breast cancer risk among participants in both study stages, as well as promising results from in silico analysis. Additional genotyping was carried out among 2,475 cases and 2,343 controls from the SBCGS, as well as among 5,077 cases and 5,384 controls from six studies in the Asian Breast Cancer Consortium (stage III). Pooled analysis of all data indicated that minor allele homozygotes (GG) of TGFBR2 rs1078985 had a 24% reduced risk of breast cancer compared with major allele carriers (AG or AA; OR, 0.76; 95% CI, 0.65–0.89; P = 8.42 × 10−4).Conclusion: These findings support a role for common genetic variation in TGF-β signaling pathway genes, specifically in TGFBR2, in breast cancer susceptibility.Impact: These findings may provide new insights into the etiology of breast cancer as well as future potential therapeutic targets. Cancer Epidemiol Biomarkers Prev; 21(7); 1176–84. ©2012 AACR.

Supplementary Methods and Materials from Replication and Functional Genomic Analyses of the Breast Cancer Susceptibility Locus at 6q25.1 Generalize Its Importance in Women of Chinese, Japanese, and European Ancestry

PDF file - 2.2MB, Supplementary figure 1. IC 50 shows that AK47 is more resistant than its parental cell line ZR-75-1, although response to tamoxifen treatment was still observed. Supplementary figure 2. Heat map of 11 splice variants selected for further q-PCR validation Supplementary figure 3. BQ323636.1 was over-expressed in 293T and Hela cell lines to prove its predicted molecular weight Supplementary figure 4. In ER positive patients who have received tamoxifen treatment, BQ mRNA expression level is not significantly correlated with chest wall/breast relapse. Supplementary figure 5. BQ mRNA level and BQ/WT ratio correlates with ER and PR status while BQ/WT ratio correlates with "triple-negative" status. Supplementary figure 6. Schematic representation of the functional domains of NCOR2 wild type and variant BQ323636.1 and the amino acid sequence similarity of NCOR2 among different species. Supplementary figure 7. Schematic illustration showing the postulated dominant negative inhibitory effect of splice variant BQ323636.1 on the co-repressor function of NCOR2 wild type for ER� transcriptional activity. Supplementary table 1. Brest cancer cell lines used in SpliceArray profiling, and summary of the TaqMan real time qPCR validation results. Supplementary table 2. Primer and Taqman probe sequences used in qPCR validation Supplementary table 3. The correlation between BQ mRNA level, BQ/WT ratio and various clinical pathological parameters

We evaluated the generalizability of a single nucleotide polymorphism (SNP), rs2046210 (A/G allele), associated with breast cancer risk that was initially identified at 6q25.1 in a genome-wide association study conducted among Chinese women. In a pooled analysis of more than 31,000 women of East-Asian, European, and African ancestry, we found a positive association for rs2046210 and breast cancer risk in Chinese women [ORs (95% CI) = 1.30 (1.22–1.38) and 1.64 (1.50–1.80) for the AG and AA genotypes, respectively, P for trend = 1.54 × 10−30], Japanese women [ORs (95% CI) = 1.31 (1.13–1.52) and 1.37 (1.06–1.76), P for trend = 2.51 × 10−4], and European-ancestry American women [ORs (95% CI) = 1.07 (0.99–1.16) and 1.18 (1.04–1.34), P for trend = 0.0069]. No association with this SNP, however, was observed in African American women [ORs (95% CI) = 0.81 (0.63–1.06) and 0.85 (0.65–1.11) for the AG and AA genotypes, respectively, P for trend = 0.4027]. In vitro functional genomic studies identified a putative functional variant, rs6913578. This SNP is 1,440 bp downstream of rs2046210 and is in high linkage disequilibrium with rs2046210 in Chinese (r2 = 0.91) and European-ancestry (r2 = 0.83) populations, but not in Africans (r2 = 0.57). SNP rs6913578 was found to be associated with breast cancer risk in Chinese and European-ancestry American women. After adjusting for rs2046210, the association of rs6913578 with breast cancer risk in African Americans approached borderline significance. Results from this large consortium study confirmed the association of rs2046210 with breast cancer risk among women of Chinese, Japanese, and European ancestry. This association may be explained in part by a putatively functional variant (rs6913578) identified in the region. Cancer Res; 71(4); 1344–55. ©2011 AACR.

Mosaic variegated aneuploidy (MVA) is a rare genetic disorder caused by mutations in BUB1B, CEP57, or TRIP13. We describe the prenatal diagnosis, molecular characterization, and clinical management of a long‐lived patient with BUB1B‐related MVA.

Background Beckwith–Wiedemann syndrome (BWS) is an overgrowth syndrome with variable clinical phenotype and complex molecular aetiology. It is mainly caused by dysregulation of the chromosome 11p15 imprinted region, which results in overgrowth in multiple tissues, often in a mosaic manner. Case presentation A large-for-gestational-age infant without any other somatic features of BWS presented with medically refractory hyperinsulinism (HI) requiring 80% pancreatectomy. Next generation sequencing with congenital HI sequencing panel identified a pathogenic ABCC8:c.1792C > T (p.Arg598Ter) variant of paternal origin, suggestive of focal HI. However, pancreatic histology revealed atypical findings of coalescing nests and trabeculae of adenomatosis scattered with islets with isolated enlarged, hyperchromatic nuclei scattered throughout the pancreas. Methylation analysis, SNP-based chromosomal microarray and short tandem repeat markers analysis revealed mosaic segmental paternal uniparental disomy (UPD) 11p15.5-p15.1 in the pancreatic tissue, but not the peripheral blood, suggestive of BWS/BW-spectrum HI. Conclusions This case highlights the importance of integrating the clinical presentation and subsequent clinical course, together with radiological, genetic and histological findings in the definitive diagnosis of this rare yet clinically important entity. In addition, this is the first report that demonstrated the level of paternal inherited c.1792 T pathogenic variant in the pancreatic tissue being directly correlated to the mosaic level of pUPD.

The chromosome periphery (CP) is a complex network that covers the outer surface of chromosomes. It acts as a carrier of nucleolar components, helps maintain chromosome structure, and plays an important role in mitosis. Current methods for fluorescence imaging of CP largely rely on immunostaining. We herein report a small‐molecule fluorescent probe, ID‐IQ, which possesses aggregation‐induced emission (AIE) property, for CP imaging. By labelling the CP, ID‐IQ sharply highlighted the chromosome boundaries, which enabled rapid segmentation of touching and overlapping chromosomes, direct identification of the centromere, and clear visualization of chromosome morphology. ID‐IQ staining was also compatible with fluorescence in situ hybridization and could assist the precise location of the gene in designated chromosome. Altogether, this study provides a versatile cytogenetic tool for improved chromosome analysis, which greatly benefits the clinical diagnostic testing and genomic research., Peripheral vision: A small‐molecule fluorescent probe with aggregation‐induced emission was developed for chromosome periphery imaging, which facilitates the segmentation of touching or overlapping chromosome clusters, identification of the centromere, and visualization of chromosome morphology. Its compatibility with FISH assays makes it a practical cytogenetic tool in assisting the precise location of a gene in designated chromosomes.

It is difficult to prenatally identify 5p deletion (-) syndrome. Here, we report five cases of 5p- syndrome diagnosed by invasive prenatal diagnosis. Of them, three had a small cerebellum in the second trimester. In one case, a prominent renal pelvis and an absent nasal bone were also found in the first trimester. However, there were no abnormal ultrasound findings in the other two cases. Two cases had noninvasive prenatal testing and one showed a '5p- syndrome positive result' because of reduced amount of cell-free DNA in 5p. Two had combined first-trimester screening performed where one had a high-risk result for trisomy 18 and a low pregnancy-associated plasma protein-A level. Two cases of 5p- syndrome resulted from a parental balanced translocation. Prenatal diagnosis will only be made on invasive prenatal diagnosis for abnormal ultrasound findings with small cerebellum, abnormal prenatal screening or a parental reciprocal translocation involving 5p.

Background When cell-free DNA (cfDNA) testing is used as a secondary screening tool following combined first-trimester screening (cFTS), cFTS is used to estimate the prior risk for chromosome abnormalities. This study aimed to assess the factors that are associated with common and atypical abnormalities following cFTS, including cFTS risk, advanced maternal age, increased nuchal translucency (NT) ≥3.5 mm, and abnormal levels of serum markers. Methods We reviewed a historical cohort of 1855 Chinese women carrying singleton pregnancies with a positive cFTS [at a threshold of 1:250 for trisomy (T) 21 or 1:180 for T18] in one public hospital over a five-year period. All chromosome abnormalities were confirmed by invasive prenatal diagnosis (IPD) with karyotyping, with or without array comparative genomic hybridization. Using multivariable binary logistic regression analysis, we determined the parameters that were associated with common and atypical abnormalities. Results Overall, the prevalence of common and atypical abnormalities was 6.2 and 1.2%, respectively, and the prevalence increased with the risk of T21 by cFTS. In pregnancies with a risk of T21 > 1 in 100, a high risk of both T21 and T18, an increased NT, or a pregnancy-associated plasma A (PAPP-A) level

Summary Objective Early onset drug‐resistant epilepsy is a neurologic disorder in which 2 antiepileptic drugs fail to maintain the seizure‐free status of the patient. Heterogeneous clinical presentations make the diagnosis challenging. We aim to identify the underlying genetic causes of a pediatric cohort with drug‐resistant epilepsy and evaluate whether the findings can provide information on patient management. Methods We include patients with drug‐resistant epilepsy onset before 18 years of age. Singleton clinical chromosomal microarray (CMA) followed by whole exome sequencing (WES) was performed using genomic DNA. In the first‐tier analysis of the exome data, we aimed to identify disease‐causing mutations in 546 genes known to cause, or to be associated with, epilepsy. For negative cases, we proceeded to exome‐wide analysis. Rare coding variants were interrogated for pathogenicity based on the American College of Medical Genetics and Genomics (ACMG) guidelines. Results We recruited 50 patients. We identified 6 pathogenic or likely pathogenic mutations, giving a diagnostic yield of 12%. Mutations were found in 6 different genes: SCN8A, SCN1A, MECP2, CDKL5, DEPDC5, and CHD2. The CDKL5 variant was found to be mosaic. One variant of unknown significance (VUS) in KCNT1 was found in a patient with compatible clinical features. Of note, a reported pathogenic SCN5A mutation known to contribute to Brugada syndrome, was also found in the patient with an SCN1A mutation. Significance Our study suggests that singleton WES is an effective diagnostic tool for drug‐resistant epilepsy. Genetic diagnosis can help to consolidate the clinical diagnosis, to facilitate phenotypic expansion, and to influence treatment and management options for seizure control in our patients. In our study, a significant portion of the genetic findings are known to be associated with an increased risk of sudden unexpected death in epilepsy (SUDEP). These findings could assist with more appropriate management in patients with epilepsy.

Balanced chromosomal abnormalities (BCAs) are changes in the localization or orientation of a chromosomal segment without visible gain or loss of genetic material. BCAs occur at a frequency of 1 in 500 newborns and are associated with an increased risk of multiple congenital anomalies and/or neurodevelopmental disorders, especially if it is a de novo mutation. In this pilot project, we used short read genome sequencing (GS) to retrospectively re-sequence ten prenatal subjects with de novo BCAs and compared the performance of GS with the original karyotyping. GS characterized all BCAs found by conventional karyotyping with the added benefit of precise sub-band delineation. By identifying BCA breakpoints at the nucleotide level using GS, we found disruption of OMIM genes in three cases and identified cryptic gain/loss at the breakpoints in two cases. Of these five cases, four cases reached a definitive genetic diagnosis while the other one case had a BCA interpreted as unknown clinical significance. The additional information gained from GS can change the interpretation of the BCAs and has the potential to improve the genetic counseling and perinatal management by providing a more specific genetic diagnosis. This demonstrates the added clinical utility of using GS for the diagnosis of BCAs.

Schuurs-Hoeijmakers syndrome (SHS) is a rare syndrome involving a de novo variant in the PACS1 gene on chromosome 11q13. There are 36 individuals published in the literature so far, mostly diagnosed postnatally (34/36) after recognizing the typical facial features co-occurring with developmental delay, intellectual disability, and multiple malformations. Herein, we present one prenatal and 15 postnatal cases with the recurrent heterozygous pathogenic variant NM_018026.3:c.607C>T p.(Arg203Trp) in the PACS1 gene detected by exome sequencing. These 16 cases were identified by mining Centogene and the Hong Kong clinical genetic service databases. Collectively, the 49 postnatally diagnosed individuals present with typical facial features and developmental delay, while the three prenatally diagnosed individuals present with multiple congenital anomalies. In the current study, the use of exome sequencing as an unbiased diagnostic tool aided the diagnosis of SHS (pre- and postnatally). The identification of additional cases with SHS add to the current understanding of the clinical phenotype associated with pathogenic PACS1 variants. Databases combining clinical and genetic information are helpful for the study of rare diseases.

Background Autosomal recessive or compound heterozygous mutations in KLHL40 cause nemaline myopathy 8, which is one of the most severe forms of nemaline myopathy. The KLHL40 c.1516A>C variant has recently been reported as a founder mutation in southern Chinese. Methods We report six cases of nemaline myopathy 8 which involves the c.1516A>C variant, from five unrelated families of non‐consanguineous southern Chinese. The pre‐ and postnatal phenotypes of these cases were reviewed with emphasis on prenatal clinical features. Genetic testing for the founder mutation was performed on three patients with homozygous mutations. Results Common prenatal features included reduced fetal movement, polyhydramnios, breech presentation, and clubfeet. Two pregnancies were terminated. Four live‐born patients had postnatal features typical of nemaline myopathy 8. The length of survival ranged from 49 days to 17 months, with respiratory failure and infections being the principal causes of death. Haplotype analysis in three patients with homozygous mutation showed a shared haplotype block of 1.1727 cM spanning over the c.1516A>C variant, suggesting it is a southern Chinese‐specific founder mutation. Conclusion Analysis of the KLHL40 c.1516A>C variant should be considered in prenatal diagnosis of Chinese pregnant patients with suspected congenital neuromuscular disorders or with significant family history of congenital myopathies., We reported six cases from five unrelated families of non‐consanguineous southern Chinese affected by nemaline myopathy 8, with either homozygous variants or compound heterozygous variants involving c.1516A>C in KLHL40. Pre‐ and postnatal phenotypes of the cases were reviewed, with emphasis on the prenatal clinical features.

We derived an integration-free induced pluripotent stem cell (iPSC) line from the peripheral blood mononuclear cells (PBMCs) of a 23-year-old male patient. This patient carries a 5′ splice site point mutation in intron 1 (c.31+1G > A) of the dystrophin gene, a mutation associated with X-linked dilated cardiomyopathy (XLDCM). Sendai virus was used to reprogram the PBMCs and deliver OCT3/4, SOX2, c-MYC, and KLF4 factors. The iPSC line (HKUi002-A) generated preserved the mutation, expressed common pluripotency markers, differentiated into three germ layers in vivo, and exhibited a normal karyotype. Further differentiation into cardiomyocytes enables the study of the disease mechanisms of XLDCM.

Background Whole-exome sequencing (WES) has become an invaluable tool for genetic diagnosis in paediatrics. However, it has not been widely adopted in the prenatal setting. This study evaluated the use of WES in prenatal genetic diagnosis in fetuses with structural congenital anomalies (SCAs) detected on prenatal ultrasound. Method Thirty-three families with fetal SCAs on prenatal ultrasonography and normal chromosomal microarray results were recruited. Genomic DNA was extracted from various fetal samples including amniotic fluid, chorionic villi, and placental tissue. Parental DNA was extracted from peripheral blood when available. We used WES to sequence the coding regions of parental-fetal trios and to identify the causal variants based on the ultrasonographic features of the fetus. Results Pathogenic mutations were identified in three families (n = 3/33, 9.1%), including mutations in DNAH11, RAF1 and CHD7, which were associated with primary ciliary dyskinesia, Noonan syndrome, and CHARGE syndrome, respectively. In addition, variants of unknown significance (VUSs) were detected in six families (18.2%), in which genetic changes only partly explained prenatal features. Conclusion WES identified pathogenic mutations in 9.1% of fetuses with SCAs and normal chromosomal microarray results. Databases for fetal genotype-phenotype correlations and standardized guidelines for variant interpretation in prenatal diagnosis need to be established to facilitate the use of WES for routine testing in prenatal diagnosis. Electronic supplementary material The online version of this article (10.1186/s12920-018-0409-z) contains supplementary material, which is available to authorized users.

A fetus of Chinese descent presented with ultrasound features of anemia at 20 weeks' gestation. Father had low a mean corpuscular volume (MCV) level. Multiplex gap-polymerase chain reaction (gap-PCR) excluded common α-thalassemia (α-thal) deletions and mutations and PCR sequencing of the α1- and α2-globin genes were negative. The fetus had a normal karyotype. Array comparative genomic hybridization (aCGH) showed a single copy loss of 189.87 kb in chromosome 11p15.4, involving the whole β-globin gene cluster, inherited from the father. Multiplex ligation-dependent probe amplification (MLPA) confirmed the deletion included the e-globin gene, confirming the diagnosis of heterozygous (eγδβ)0-thalassemia [(eγδβ)0-thal], also inherited from the father. The fetus had a worsening anemic condition in utero and required a transfusion at 26 weeks' gestation, raising the hemoglobin (Hb) level from 5.3 to 12.6g/dL. A cesarean-section was subsequently performed at 32 weeks' gestation because of reduced fetal movements, and a 1650g baby girl with good Apgar scores was delivered. Hemoglobin at birth was 12.8g/dL, gradually dropping to 6.8 g/dL, requiring three neonatal transfusions. Her condition gradually stabilized after 2 months with Hb stable at 8.0 g/dL. Family screening by MLPA showed that the paternal grandmother carried the same deletion. The deletion in this case is distinct and is the reported first case. The deletion transmitted across three successive generations with great phenotypic variation. The final adult phenotype of (eγδβ)0-thal is usually mild, therefore, with accurate prenatal diagnosis this condition is salvageable by in utero and early neonatal transfusions, preventing adverse pregnancy and neonatal outcomes.

Common genetic variants in 183 loci have been identified in relation to breast cancer risk in genome-wide association studies (GWAS). These risk variants combined explain only a relatively small proportion of breast cancer heritability, particularly in Asian populations. To search for additional genetic susceptibility loci for breast cancer, we performed a meta-analysis of data from GWAS conducted in Asians (24,206 cases and 24,775 controls). Variants showing an association with breast cancer risk at P < 0.01 were evaluated in GWAS conducted in European women including 122,977 cases and 105,974 controls. In the combined analysis of data from both Asian and European women, the lead variant in 28 loci not previously reported showed an association with breast cancer risk at P < 5 ×10−8. In the meta-analysis of all GWAS data from Asian and European descendants, we identified SNPs in three additional loci in association with breast cancer risk at P < 5 ×10−8. The associations for 10 of these loci were replicated in an independent sample of 16,787 cases and 16,680 controls of Asian women (P < 0.05). Expression quantitative trait locus (eQTL) and gene-based analyses provided evidence for the possible involvement of the YBEY, MAN2C1, SNUPN, TBX1, SEMA4A, STC1, MUTYH, LOXL2, and LINC00886 genes underlying the associations observed in eight of these 28 newly identified risk loci. In addition, we replicated the association for 78 of the 166 previously reported risk variants at P < 0.05 in women of Asian descent using GWAS data. These findings improve our understanding of breast cancer genetics and etiology and extend to Asian populations previous findings from studies of European women.

Known risk variants explain only a small proportion of breast cancer heritability, particularly in Asian women. To search for additional genetic susceptibility loci for breast cancer, here we perform a meta-analysis of data from genome-wide association studies (GWAS) conducted in Asians (24,206 cases and 24,775 controls) and European descendants (122,977 cases and 105,974 controls). We identified 31 potential novel loci with the lead variant showing an association with breast cancer risk at P, In breast cancer, genome-wide associations studies (GWAS) have highlighted loci associated with disease risk. Here, the authors perform a meta-analysis of GWAS data from Asian populations, discovering 31 potential new risk loci, 10 of which are validated in an independent disease cohort.

Background Chromosomal microarray (CMA) has been shown to be cost-effective over karyotyping in invasive prenatal diagnosis for pregnancies with fetal ultrasound anomalies. Yet, information regarding preceding and subsequent tests must be considered as a whole before the true cost-effectiveness can emerge. Currently in Hong Kong, karyotyping is offered free as the standard prenatal test while genome-wide array comparative genome hybridization (aCGH), a form of CMA, is self-financed. A new algorithm was proposed to use aCGH following quantitative fluorescent polymerase chain reaction (QF-PCR) as primary test instead of karyotyping. This study aims to evaluate the cost-effectiveness of the proposed algorithm versus the current algorithm for prenatal diagnosis in Hong Kong. Methods Between November 2014 and February 2016, 129 pregnant women who required invasive prenatal diagnosis at two public hospitals in Hong Kong were prospectively recruited. The proposed algorithm was performed for all participants in this demonstration study. For the cost-effectiveness analysis, cost and outcome (diagnostic rate) data were compared with that of a hypothetical scenario representing the current algorithm. Further analysis was performed to incorporate women’s willingness-to-pay for the aCGH test. Impact of government subsidies on the aCGH test was explored as a sensitivity analysis. Results The proposed algorithm dominated the current algorithm for prenatal diagnosis. Both algorithms were equally effective but the proposed algorithm was significantly cheaper (p ≤ 0.05). Taking into account women’s willingness-to-pay for an aCGH test, the proposed algorithm was more effective and less costly than the current algorithm. When the government subsidy reaches 100%, the maximum number of diagnoses could be made. Conclusion By switching to the proposed algorithm, cost saving can be achieved whilst maximizing the diagnostic rate for invasive prenatal diagnosis. It is recommended to implement aCGH as a primary test following QF-PCR to replace the majority of karyotyping for prenatal diagnosis in Hong Kong.

Chromosomal microarray (CMA) is recommended as a first tier investigation for patients with developmental delay (DD), intellectual disability (ID), autistic spectrum disorder (ASD), and multiple congenital anomalies (MCA). It is widely used in the prenatal and postnatal settings for detection of chromosomal aberrations. This is a retrospective review of all array comparative genomic hybridization (aCGH/ array CGH) findings ascertained in two major prenatal and postnatal genetic diagnostic centers in Hong Kong from June 2012 to December 2017. Medical records were reviewed for cases with pathogenic and variants of uncertain clinical significance (VUS). Classification of copy number variants (CNVs) was based on current knowledge and experience by August 2018. The aims of this review are to study the diagnostic yield of array CGH application in prenatal and postnatal settings in Hong Kong and to describe the spectrum of abnormalities found. Prenatal indications included abnormal ultrasound findings, positive Down syndrome screening, abnormal noninvasive prenatal test results, advanced maternal age and family history of chromosomal or genetic abnormalities. Postnatal indications included unexplained DD, ID, ASD, and MCA. A total of 1,261 prenatal subjects and 3,096 postnatal patients were reviewed. The prenatal diagnostic yield of pathogenic CNV and VUS (excluding those detectable by karyotype) was 3.5%. The postnatal diagnostic yield of pathogenic CNV was 15.2%. The detection rates for well-defined microdeletion and microduplication syndromes were 4.6% in prenatal and 6.1% (1 in 16 index patients) in postnatal cases, respectively. Chromosomes 15, 16, and 22 accounted for over 21 and 25% of pathogenic CNVs detected in prenatal and postnatal cohorts, respectively. This review provides the first large scale overview of genomic imbalance of mostly Chinese patients in prenatal and postnatal settings.

Background Cystic fibrosis (CF) is a rare condition in Asians. Since 1985, only about 30 Chinese patients have been reported with molecular confirmation. Method Using our in-house next-generation sequencing (NGS) pipeline for childhood bronchiectasis, we identified disease-causing CFTR mutations in CF patients in Hong Kong. After identifying p.I1023R in multiple patients, haplotype analysis was performed with genome-wide microarray to ascertain the likelihood of this being a founder mutation. We also assessed the processing and gating activity of the mutant protein by Western hybridization and patch-clamp test. Results Molecular diagnoses were confirmed in four patients, three of whom shared a missense mutation: CFTR:c.3068T>G:p.I1023R. The results suggested that p.I1023R is a founder mutation in southern Han Chinese. In addition, the processing and gating activity of the mutant protein was assessed by gel electrophoresis and a patch-clamp test. The mutant protein exhibited trafficking defects, suggesting that the dysfunction is caused by reduced cell surface expression of the fully glycosylated proteins. Conclusion Together with other previously reported mutations, the specific founder mutation presented herein suggests a unique CFTR mutation spectrum in the southern Chinese populations, and this finding has vital implications for improving molecular testing and mutation-specific treatments for Chinese patients with CF.

In this first Asian study, the decision outcomes (decision conflict, decision regret, and anxiety) of 262 pregnant women offered noninvasive prenatal test (NIPT) for high-risk Down screening results were assessed. Decision conflict was experienced by 3.5% and level of decisional regret low (mean score 15.7, 95%CI 13.2–18.3). All 13 cases of decisional regret were NIPT acceptors. Elevated anxiety was experienced by 55.9% at the time of decision making about NIPT and persistent in 30.3%. Insufficient knowledge about NIPT was associated with elevated anxiety at decision making (p = .011) and with decisional regret (p = .016). Decisional regret was associated with prolonged anxiety (p = .010).

Uniparental disomy (UPD) refers to the genetic phenomenon in which both homologous chromosomes are inherited from the same parent, either maternal or paternal. The UPD phenotype is chromosome speci...

The purpose of this study was to develop and test an original self-rating instrument known as Brief Medication Adherence Scale (BMAS) to assess antipsychotic adherence level of Hong Kong Chinese patients with schizophrenia. On the interview day, BMAS and three other validated rating scales were given to local patients with schizophrenia and related disorders for completion. BMAS was required to fill in a second time after two weeks for the study of test-retest reliability. Results of BMAS were matched with those of other scales and blood level of prescribed mood stabilizers to test for construct validity. Data analysis was performed for 84 patients. Median BMAS scores recorded at both times were identical at 89/100, and a cutoff score of 70 was considered medication adherent with a sensitivity of 98.61% (CI 92.50%-99.96%). BMAS was positively and significantly correlated with the established Medication Adherence Rating Scale -Taiwanese (Spearman's ρ = 0.56, p 0.05) and with variation in serum mood stabilizer level (Pearson's r = 0.55, p 0.05). On the other hand, correlations with scales measuring mental condition and medication side effects were weak. Principal component analysis found two components (i.e. medication taking behaviors and attitudes) for the 10-question BMAS. Test-retest BMAS total scores were significantly correlated (intraclass correlation alpha = 0.87, p 0.05), and Cronbach's alpha measuring internal consistency was 0.68. The current study confirms that BMAS is a valid and reliable scale that assesses medication adherence in patients with schizophrenia.

BackgroundWe report here clinical, cytogenetic and molecular data for a pair of monochorionic diamniotic twins with paternal isodisomy for chromosome 19. Both twins presented with dysmorphic features and global developmental delay. This represents, to our knowledge, the first individual human case of paternal uniparental disomy for chromosome 19 (UPD19).MethodsWhole-exome sequencing, together with conventional karyotype and SNP array analysis were performed along with genome-wide DNA methylation array for delineation of the underlying molecular defects.ResultsConventional karyotyping on amniocytes and lymphocytes showed normal karyotypes for both twins. Whole-exome sequencing did not identify any pathogenic sequence variants but >5000 homozygous exonic variants on chromosome 19, suggestive of UPD19. SNP arrays on blood and buccal DNA both showed paternal isodisomy for chromosome 19. Losses of imprinting for known imprinted genes on chromosome 19 were identified, including ZNF331, PEG3, ZIM2 and MIMT1. In addition, imprinting defects were also identified in genes located on other chromosomes, including GPR1-AS, JAKMP1 and NHP2L1.ConclusionImprinting defects are the most likely cause for the dysmorphism and developmental delay in this first report of monozygotic twins with UPD19. However, epigenotype-phenotype correlation will require identification of additional individuals with UPD19 and further molecular analysis.

Objective To evaluate the 1-year clinical outcomes of patients who received the Resolute Onyx™ stent. Methods This was a single-centre, retrospective registry analysis that reviewed the clinical data from all patients who were implanted with a Resolute Onyx™ stent between March 2015 and February 2016. Clinical follow-up was performed at 1 year post-implantation. Results A total of 252 patients received a Resolute Onyx™ stent and two patients were lost to follow-up. The mean age of the cohort was 66.9 years and 113 (45.2%) had diabetes mellitus. Thirty-eight patients (15.2%) had left main disease and 73 (29.2%) had three-vessel disease. A total of 175 patients (70.0%) had small vessel disease (20 mm). The 1-year target lesion failure was 4.4% (11 of 250), cardiovascular death occurred in eight patients (3.2%), ischaemia-driven target lesion revascularization was undertaken in five patients (2.0%) and stent thrombosis occurred in one patient (0.4%). Conclusion The Resolute Onyx™ stent showed a favourable 1-year clinical performance in a real-world population.

Background Array comparative genomic hybridization (aCGH) is recommended as a first-tier genetic test for children with autism spectrum disorder (ASD). However, interpretation of results can often be challenging partly due to the fact that copy number variants (CNVs) in non-European ASD patients are not well studied. To address this literature gap, we report the CNV findings in a cohort of Chinese children with ASD. Methods DNA samples were obtained from 258 Chinese ASD patients recruited from a child assessment center between January 2011 and August 2014. aCGH was performed using NimbleGen-CGX-135k or Agilent-CGX 60k oligonucleotide array. Results were classified based on existing guidelines and literature. Results Ten pathogenic CNVs and one likely pathogenic CNV were found in nine patients, with an overall diagnostic yield of 3.5%. A 138 kb duplication involving 3′ exons of DPP10 (arr[GRCh37] 2q14.1(116534689_116672358)x3), reported to be associated with ASD, was identified in one patient (0.39%). The same CNV was reported as variant of uncertain significance (VUS) in DECIPHER database. Multiple individuals of typical development carrying a similar duplication were identified among our ancestry-matched control with a frequency of 6/653 (0.92%) as well as from literature and genomic databases. Conclusions The DPP10 duplication is likely a benign CNV polymorphism enriched in Southern Chinese with a population frequency of ~1%. This highlights the importance of using ancestry-matched controls in interpretation of aCGH findings. Electronic supplementary material The online version of this article (doi:10.1186/s13229-017-0136-x) contains supplementary material, which is available to authorized users.

Hydrops fetalis is commonly due to Hb Bart's (γ4) disease in South East Asia. Here, we report an unusual case of hydrops fetalis due to congenital dyserythropoietic anemia (CDA) associated with compound heterozygosity for Kruppel-like factor 1 (KLF1) gene mutations. Fetal cardiomegaly was first detected on routine mid-trimester scan in a pregnant woman with normal mean corpuscular volume (MCV) and Rhesus positive status. The fetus subsequently developed hydrops fetalis, and cordocentesis showed severe fetal anemia with a hemoglobin (Hb) level of 3.4 g/dL. Common causes of fetal anemia including Hb Bart's disease, parvovirus infection, and red cell antibodies were excluded. In view of the marked increase in erythroblasts at various stages of erythropoiesis, the diagnosis of CDA was suspected. We screened the couple for previously reported KLF1 gene mutations, showing that the mother was heterozygous for the c.525_526insCGGCGCC, p.Gly176Argfs*179 mutation, and her husband heterozygous for c.1012C>A, p.Pro338Thr mutation. The fetus was a compound heterozygote for these two KLF1 mutations. After counseling, repeated intrauterine transfusions were given at 27, 29, and 34 weeks' gestation; the hydrops fetalis was resolved. The baby was delivered at 34 weeks' gestation and required monthly blood transfusions but was otherwise thriving. Bone marrow aspiration at 10 months of age showed the features of ineffective erythropoiesis, compatible with CDA. In conclusion, hydrops fetalis can rarely be due to CDA associated with a compound heterozygous mutation for KLF1 gene mutations, and be managed by repeated intrauterine transfusions. Our present report adds to the wide clinical spectrum of KLF1 mutations.

In a three-stage genome-wide association study among East Asian women including 22,780 cases and 24,181 controls, we identified three novel genetic loci associated with breast cancer risk, including rs4951011 at 1q32.1 (in intron 2 of the ZC3H11A gene, P = 8.82 × 10−9), rs10474352 at 5q14.3 (near the ARRDC3 gene, P = 1.67 × 10−9), and rs2290203 at 15q26.1 (in intron 14 of the PRC1 gene, P = 4.25 × 10−8). These associations were replicated in European-ancestry populations including 16,003 cases and 41,335 controls (P = 0.030, 0.004, and 0.010, respectively). Data from the ENCODE project suggest that variants rs4951011 and rs10474352 may be located in an enhancer region and transcription factor binding sites, respectively. This study provides additional insights into the genetics and biology of breast cancer.

We report on a baby girl with multiple congenital abnormalities, including cleft palate, intrauterine growth restriction, and double outlet right ventricle (DORV) with ventricular septal defect. She had an unbalanced chromosome translocation t (X;15) resulting in monosomy 15pter → p10 and trisomy Xq13.1 → q28. All three copies of Xq encompass the XIST gene. It is known that X chromosome inactivation could spread to the autosome part of an unbalanced translocation involving chromosome X and an autosome. To confirm the spread of X chromosome inactivation on chromosome 15, we evaluate the methylation change by the HumanMethylation450 BeadChip, a whole genome DNA methylation micorarray that includes 15,259 probes spanning 717 genes on chromosome 15. Results showed there was gain in DNA methylation of more than 20% in 586 CpG sites spanning the long arm of chromosome 15. We further examined the hypermethylated CpG sites located in CpG-island promoter, because genes subjected to X chromosome inactivation will have an increase in DNA methylation level in this region. A total of 75 sites representing 24 genes were hypermethylated. Nearly all of these probes are located in region proximal to the breakpoint, from 15q11.2 to 15q21.3 (35Mb) suggesting that X inactivation was spread to the proximal region of 15q. Gain of DNA methylation, especially in the CpG-island promoter, can result in functional inactivation of genes, and therefore could potentially worsen the phenotype of our patient.

Copy number gain of 17p13.3 has been shown to be associated with developmental delay/autism and Split-Hand-Foot malformation. We report a case of fetus with bilateral split-hand malformation detected on prenatal ultrasound. Array comparative genomic hybridization detected 2 maternally inherited copy number gains in the 17p13.3 region with one of them involving the BHLHA9 gene and part of the YWHAE gene. The mother is normal in intelligence with mild right foot anomaly only. Although the BHLHA9 copy gain is known to be associated with split-hand-foot malformation, the penetrance and expressivity is highly variable. More challenging is the effect of partial YWHAE copy number gain on neurodevelopment is inconclusive based on current literature. This case highlights the difficulties of prenatal genetic counseling in array comparative genomic hybridization findings in clinical situation with incomplete understanding of genotype-phenotype correlation.

Purpose: Deregulation of miRNAs is associated with almost all human malignancies. Human papillomavirus (HPV)-associated oropharyngeal carcinoma (OPC) has a significantly more favorable outcome compared with HPV-negative OPCs; however, the underlying mechanisms are not well understood. Hence, the objectives of this study were to determine whether miRNA expression differed as a function of HPV status and to assess whether such miRNAs provide prognostic value beyond HPV status. Methods: Global miRNA profilings were conducted on 88 formalin-fixed and paraffin-embedded (FFPE) OPC biopsies (p16-positive: 56; p16-negative: 32), wherein the expression levels of 365 miRNAs plus 3 endogenous controls were simultaneously measured using quantitative real-time (qRT)-PCR. Seven FFPE specimens of histologically normal tonsils were used as controls. Results: Overall, 224 miRNAs were expressed in more than 80% of the investigated samples, with 128 (57%) being significantly differentially expressed between tumor versus normal tissues (P < 0.05). Upregulated miR-20b, miR-9, and miR-9* were significantly associated with HPV/p16-status. Three miRNA sets were significantly associated with overall survival (miR-107, miR-151, miR-492; P = 0.0002), disease-free survival (miR-20b, miR-107, miR-151, miR-182, miR-361; P = 0.0001), and distant metastasis (miR-151, miR-152, miR-324-5p, miR-361, miR492; P = 0.0087), which retained significance even after adjusting for p16 status. The associated biologic functions of these miRNAs include immune surveillance, treatment resistance, invasion, and metastasis. Conclusion: We have identified several miRNAs, which associate with HPV status in OPC; furthermore, three candidate prognostic sets of miRNAs seem to correlate with clinical outcome, independent of p16 status. Furthermore, evaluations will offer biologic insights into the mechanisms underlying the differences between HPV-positive versus HPV-negative OPC. Clin Cancer Res; 19(8); 2154–62. ©2013 AACR.

A low level of PAPP-A predicts adverse fetal outcomes. As Chinese pregnant women have a higher level of PAPP-A, the predictive performance of PAPP-A and its optimal cutoff value might be different. This study aims to establish a PAPP-A cutoff value in the Chinese population that identifies adverse fetal outcomes. We retrospectively analysed 4936 spontaneous singleton pregnancies of Chinese women who underwent first-trimester combined Down's screening in our unit from March 2010 to January 2014 and had delivery information available. A composite adverse fetal outcome encompassed intrauterine fetal loss (including miscarriages and stillbirths), and live births either before 32 weeks or weighing less than -2 standard deviation (SD) for gestation. The area under the curve of the receiver-operator characteristic curve for prediction of the composite adverse outcome using PAPP-A was 0.626 (95% CI =0.612-0.640, p

Background: The TGF-β signaling pathway plays a significant role in the carcinogenic process of breast cancer. Methods: We systematically evaluated associations of common variants in TGF-β signaling pathway genes with breast cancer risk using a multistage, case–control study among Asian women. Results: In the first stage, 341 single-nucleotide polymorphisms with minor allele frequencies ≥ 0.05 across 11 genes were evaluated among 2,926 cases and 2,380 controls recruited as a part of the Shanghai Breast Cancer Genetics Study (SBCGS). In the second stage, 20 SNPs with promising associations were evaluated among an additional 1,890 cases and 2,000 controls from the SBCGS. One variant, TGFBR2 rs1078985, had highly consistent and significant associations with breast cancer risk among participants in both study stages, as well as promising results from in silico analysis. Additional genotyping was carried out among 2,475 cases and 2,343 controls from the SBCGS, as well as among 5,077 cases and 5,384 controls from six studies in the Asian Breast Cancer Consortium (stage III). Pooled analysis of all data indicated that minor allele homozygotes (GG) of TGFBR2 rs1078985 had a 24% reduced risk of breast cancer compared with major allele carriers (AG or AA; OR, 0.76; 95% CI, 0.65–0.89; P = 8.42 × 10−4). Conclusion: These findings support a role for common genetic variation in TGF-β signaling pathway genes, specifically in TGFBR2, in breast cancer susceptibility. Impact: These findings may provide new insights into the etiology of breast cancer as well as future potential therapeutic targets. Cancer Epidemiol Biomarkers Prev; 21(7); 1176–84. ©2012 AACR.

Vascular endothelial growth factor (VEGF) has a central role in breast cancer development and progression, but the mechanisms that control its expression are poorly understood. Breast cancer tissue microarrays revealed an inverse correlation between the Forkhead transcription factor Forkhead box class O (FOXO)3a and VEGF expression. Using the lapatinib-sensitive breast cancer cell lines BT474 and SKBR3 as model systems, we tested the possibility that VEGF expression is negatively regulated by FOXO3a. Lapatinib treatment of BT474 or SKBR3 cells resulted in nuclear translocation and activation of FOXO3a, followed by a reduction in VEGF expression. Transient transfection and inducible expression experiments showed that FOXO3a represses the proximal VEGF promoter, whereas another Forkhead member, FOXM1, induces VEGF expression. Chromatin immunoprecipitation and oligonucleotide pull-down assays showed that both FOXO3a and FOXM1 bind a consensus Forkhead response element (FHRE) in the VEGF promoter. Upon lapatinib stimulation, activated FOXO3a displaces FOXM1 bound to the FHRE before recruiting histone deacetylase 2 (HDAC2) to the promoter, leading to decreased histones H3 and H4 acetylation, and concomitant transcriptional inhibition of VEGF. These results show that FOXO3a-dependent repression of target genes in breast cancer cells, such as VEGF, involves competitive displacement of DNA-bound FOXM1 and active recruitment of transcriptional repressor complexes., link_to_OA_fulltext

CD209 (DC-SIGN) is an important C-type lectin which acts a receptor of many pathogens. The single nucleotide polymorphism (SNP) −336A>G in the CD209 promoter has been demonstrated to regulate promoter activity and to be associated with several important infectious diseases, such as human immunodeficiency virus–1 (HIV-1), Mycobacterium tuberculosis, and Dengue fever. CD209 facilitates severe acute respiratory syndrome (SARS)–coronavirus spike protein-bearing pseudotype driven infection of permissive cells in vitro. In keeping with previously published findings, our in vitro studies confirmed that this SNP modulates gene promoter activity. Genetic association analysis of this SNP with clinico-pathologic outcomes in 824 serologic confirmed SARS patients showed that the −336AG/GG genotype SARS patients was associated with lower standardized lactate-dehydrogenase (LDH) levels compared with the −336AA patients (p = 0.014, odds ratio = 0.40). High LDH levels are known to be an independent predictor for poor clinical outcome, probably related to tissue destruction from immune hyperactivity. Hence, SARS patients with the CD209 −336 AA genotype carry a 60% chance of having a poorer prognosis. This association is in keeping with the role of CD209 in modulating immune response to viral infection. The relevance of these findings for other infectious diseases and inflammatory conditions would be worth investigating.

Gestational trophoblastic disease includes choriocarcinoma, a frankly malignant tumor, and hydatidiform mole (HM), which often leads to the development of persistent gestational trophoblastic neoplasia and requires chemotherapy. NANOG is an important transcription factor that is crucial for maintaining embryonic stem cell self-renewal and pluripotency. We postulated that NANOG is involved in the pathogenesis of gestational trophoblastic disease. In this study, significantly higher NANOG mRNA and protein expression levels, by quantitative PCR and immunoblotting, respectively, were demonstrated in HMs, particularly those that developed persistent disease, when compared with normal placentas. In addition, significantly increased nuclear NANOG immunoreactivity was found by immunohistochemistry in HMs (P < 0.001) and choriocarcinoma (P = 0.002). Higher NANOG expression levels were demonstrated in HMs that developed persistent disease, as compared with those that regressed (P = 0.025). Nuclear localization of NANOG was confirmed by confocal microscopy and immunoblotting in choriocarcinoma cell lines. There was a significant inverse correlation between NANOG immunoreactivity and apoptotic index assessed by M30 CytoDeath antibody (P = 0.012). After stable knockdown of NANOG in the choriocarcinoma cell line JEG-3 by an shRNA approach, increased apoptosis was observed in relation to with enhanced caspases and poly(ADP-ribose) polymerase activities. NANOG knockdown was also associated with decreased mobility and invasion of JEG-3 and down-regulation of matrix metalloproteases 2 and 9. These findings suggest that NANOG is involved in the pathogenesis and clinical progress of gestational trophoblastic disease, likely through its effect on apoptosis, cell migration, and invasion.

This study investigated the expression and methylation profiles of SOX2, a stem cell-related transcription factor, in placentas and gestational trophoblastic disease. The methylation status of SOX2 promoter region in 55 hydatidiform moles, 4 choriocarcinoma, 23 first trimester, and 15 term placentas was evaluated by methylation-specific polymerase chain reaction. The methylated allele was found in 4.4% (1/23) of first trimester placentas, 26.7% (4/15) term placentas, and 56.4% (31/55) of hydatidiform moles and all choriocarcinoma samples and cell lines. A significant reduction in SOX2 messenger RNA expression was found in the hydatidiform moles (P = .027) when compared with that in the placentas. SOX2 messenger RNA expression was significantly correlated with SOX2 hypermethylation (P < .001). SOX2 expression was restored in choriocarcinoma cell lines following treatment to 5-Aza-2(')-deoxycytidine and/or Trichostatin A, demethylation and histone deacetylase inhibitors, respectively, and the response was synergistic. Epigenetic mechanisms may play important role on the transcriptional regulation of SOX2 and contribute to pathogenesis of gestational trophoblastic disease.

Aims: To assess the expression profile of the activated form of signal transducer and activator of transcription (Stat)3 in gestational trophoblastic disease (GTD) and correlate the findings with clinicopathological parameters. Methods and results: By immunohistochemistry, both cytoplasmic and nuclear expression of p-Stat3-Ser 727 was demonstrated in 88 trophoblastic tissues, including placentas and GTD. Nuclear immunoreactivity of p-Stat3-Ser 727 was significantly higher in hydatidi-form mole (HM) (P < 0.001) and choriocarcinoma (P = 0.009) when compared with normal placentas. Placental site trophoblastic tumours (PSTT) and epithelioid trophoblastic tumours (ETT) also demonstrated higher nuclear p-Stat3-Ser 727 expression than their normal trophoblast counterparts. Higher p-Stat3-Ser 727 expression was confirmed in choriocarcinoma cell lines, JEG-3 and JAR, than in a normal trophoblast cell line, with both nuclear and cytoplasmic fractions demonstrated by immunoblotting. Spontaneously regressed HM showed significantly increased nuclear and cytoplasmic p-Stat3-Ser 727 immunoreactivity over those that developed gestational trophoblastic neoplasia (GTN) (P = 0.013, P = 0.039). There was a significant positive and inverse correlation between nuclear p-Stat3-Ser 727 immunoreactivity and apoptotic indices [terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labelling and M30 Cyto-Death antibody] (P = 0.001, P < 0.001, Spearman's p test) and Bcl-2 expression (P = 0.034), respectively. Conclusions: p-Stat3-Ser 727 plays a role in the pathogenesis of GTD, probably through the regulation of apoptosis. p-Stat3-Ser 727 immunoreactivity is a potential marker in predicting GTN in HM.

Two closely related trans-membrane C-type lectins dendritic cell-specific intracellular adhesion molecules (ICAM)-3 grabbing non-integrin (DC-SIGN or CD209) and liver/lymph node-specific ICAM-3 grabbing non-integrin (L-SIGN also known as DC-SIGNR, CD209L or CLEC4M) directly recognize a wide range of micro-organisms of major impact on public health. Both genes have long been considered to share similar overall structure and ligand-binding characteristics. This review presents more recent biochemical and structural studies, which show that they have distinct ligand-binding properties and different physiological functions. Of importance in both these genes is the presence of an extra-cellular domain consisting of an extended neck region encoded by tandem repeats that support the carbohydrate-recognition domain, which plays a crucial role in influencing the pathogen-binding properties of these receptors. The notable difference between these two genes is in this extra-cellular domain. Whilst the tandem-neck-repeat region remains relatively constant size for DC-SIGN, there is considerable polymorphism for L-SIGN. Homo-oligomerization of the neck region of L-SIGN has been shown to be important for high-affinity ligand binding, and heterozygous expression of the polymorphic variants of L-SIGN in which neck lengths differ could thus affect ligand-binding affinity. Functional studies on the effect of this tandem-neck-repeat region on pathogen-binding, as well as genetic association studies for various infectious diseases and among different populations, are discussed. Worldwide demographic data of the tandem-neck-repeat region showing distinct differences in the neck-region allele and genotype distribution among different ethnic groups are presented. These findings support the neck region as an excellent candidate acting as a functional target for selective pressures exerted by pathogens. Electronic supplementary material The online version of this article (doi:10.1007/s00109-008-0350-2) contains supplementary material, which is available to authorized users.

Epigenetic aberration is known to be important in human carcinogenesis. Promoter methylation status of RAS effector related genes, RASSF1A, RASSF2A, hDAB2IP (m2a and m2b regions) and BLU, was evaluated in 76 endometrial carcinomas and their non-neoplastic endometrial tissue by methylation specific PCR. Hypermethylation of at least one of the 5 genes was detected in 73.7% of carcinomas. There were significant correlations between methylation of hDAB2IP and RASSF1A, RASSF2A (p = 0.042, p = 0.012, respectively). Significantly, more frequent RASSF1A hypermethylation was found in Type I endometrioid carcinomas than Type II carcinomas (p = 0.049). Among endometrioid cancers, significant association between RASSF1A hypermethylation and advanced stage, as well as between methylation of hDAB2IP at m2a region with deep myometrial invasion (p < 0.05) was observed. mRNA expression of RASSF1A, RASSF2A and BLU in endometrial cancer cell lines significantly increased after treatment with the demethylating agent 5-Aza-2'-deoxycytidine supporting the repressive effect of hypermethylation on their transcription. Immunohistochemical study of DNMT1 on eight normal endometrium, 16 hyperplastic endometrium without atypia, 40 atypical complex hyperplasia and 79 endometrial carcinomas showed progressive increase in DNMT1 immunoreactivity from normal endometrium to endometrial hyperplasia and endometrioid carcinomas (p = 0.001). Among carcinomas, distinctly higher DNMT1 expression was observed in Type I endometrioid carcinomas (p < 0.001). DNMT1 immunoreactivity correlated with RASSF1A and RASSF2A methylation (p < 0.05). The data suggested that hypermethylation of RAS related genes, particularly RASSF1A, was involved in endometrial carcinogenesis with possible divergent patterns in different histological types. DNMT1 protein overexpression might contribute to such aberrant DNA hypermethylation of specific tumor suppressor genes in endometrial cancers.