Displaying publications 41 - 60 of 84 in total

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  1. Lau TP, Lian LH, Cheah PL, Looi LM, Roslani AC, Goh KL, et al.
    Eur J Cancer Prev, 2017 11;26(6):506-510.
    PMID: 28059856 DOI: 10.1097/CEJ.0000000000000336
    X-ray repair cross-complementing group 1 (XRCC1) is one of the key components in the base excision repair pathway that repairs erroneous DNA lesions and removes nonbulky base adducts for the maintenance of genome integrity. Studies have revealed that differences in individual DNA repair capacity can impact the interindividual variation in cancer susceptibility, tumour aggressiveness and treatment response. The relationship between XRCC1 and sporadic colorectal cancer (CRC) susceptibility, which is hitherto inconclusive, has been explored in many association studies of different populations. In view of the conflicting findings generated, we aimed to investigate the association between XRCC1 and genetic predisposition to CRC among Malaysians. The present case-control association study was conducted on 130 CRC patients and 212 age-matched healthy controls. The genotyping of XRCC1 Arg194Trp, Arg280His and Arg399Gln single nucleotide polymorphisms was performed with allele-specific real-time PCR approach. This was followed by basic statistical analysis on the single nucleotide polymorphisms and haplotype data obtained. No significant difference in the allele and genotype frequencies was observed between CRC patients and healthy controls (P>0.05). There was also no association observed between XRCC1 haplotypes and CRC (P>0.05). In conclusion, a positive association between XRCC1 gene polymorphisms and CRC risk was not established in our Malaysian population.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  2. Grove J, Ripke S, Als TD, Mattheisen M, Walters RK, Won H, et al.
    Nat Genet, 2019 03;51(3):431-444.
    PMID: 30804558 DOI: 10.1038/s41588-019-0344-8
    Autism spectrum disorder (ASD) is a highly heritable and heterogeneous group of neurodevelopmental phenotypes diagnosed in more than 1% of children. Common genetic variants contribute substantially to ASD susceptibility, but to date no individual variants have been robustly associated with ASD. With a marked sample-size increase from a unique Danish population resource, we report a genome-wide association meta-analysis of 18,381 individuals with ASD and 27,969 controls that identified five genome-wide-significant loci. Leveraging GWAS results from three phenotypes with significantly overlapping genetic architectures (schizophrenia, major depression, and educational attainment), we identified seven additional loci shared with other traits at equally strict significance levels. Dissecting the polygenic architecture, we found both quantitative and qualitative polygenic heterogeneity across ASD subtypes. These results highlight biological insights, particularly relating to neuronal function and corticogenesis, and establish that GWAS performed at scale will be much more productive in the near term in ASD.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  3. Poniah P, Mohd Zain S, Abdul Razack AH, Kuppusamy S, Karuppayah S, Sian Eng H, et al.
    Urol Oncol, 2017 09;35(9):545.e1-545.e11.
    PMID: 28527622 DOI: 10.1016/j.urolonc.2017.04.017
    BACKGROUND: Two key issues in prostate cancer (PCa) that demand attention currently are the need for a more precise and minimally invasive screening test owing to the inaccuracy of prostate-specific antigen and differential diagnosis to distinguish advanced vs. indolent cancers. This continues to pose a tremendous challenge in diagnosis and prognosis of PCa and could potentially lead to overdiagnosis and overtreatment complications. Copy number variations (CNVs) in the human genome have been linked to various carcinomas including PCa. Detection of these variants may improve clinical treatment as well as an understanding of the pathobiology underlying this complex disease.

    METHODS: To this end, we undertook a pilot genome-wide CNV analysis approach in 36 subjects (18 patients with high-grade PCa and 18 controls that were matched by age and ethnicity) in search of more accurate biomarkers that could potentially explain susceptibility toward high-grade PCa. We conducted this study using the array comparative genomic hybridization technique. Array results were validated in 92 independent samples (46 high-grade PCa, 23 benign prostatic hyperplasia, and 23 healthy controls) using polymerase chain reaction-based copy number counting method.

    RESULTS: A total of 314 CNV regions were found to be unique to PCa subjects in this cohort (P<0.05). A log2 ratio-based copy number analysis revealed 5 putative rare or novel CNV loci or both associated with susceptibility to PCa. The CNV gain regions were 1q21.3, 15q15, 7p12.1, and a novel CNV in PCa 12q23.1, harboring ARNT, THBS1, SLC5A8, and DDC genes that are crucial in the p53 and cancer pathways. A CNV loss and deletion event was observed at 8p11.21, which contains the SFRP1 gene from the Wnt signaling pathway. Cross-comparison analysis with genes associated to PCa revealed significant CNVs involved in biological processes that elicit cancer pathogenesis via cytokine production and endothelial cell proliferation.

    CONCLUSION: In conclusion, we postulated that the CNVs identified in this study could provide an insight into the development of advanced PCa.

    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  4. Haerian BS, Sha'ari HM, Fong CY, Tan HJ, Wong SW, Ong LC, et al.
    J Neuroimmunol, 2015 Jan 15;278:137-43.
    PMID: 25595263 DOI: 10.1016/j.jneuroim.2014.12.016
    Neuroinflammation can damage the brain and plays a critical role in the pathophysiology of epilepsy. Tissue inhibitor of metalloproteinase 4 (TIMP4) is an inflammation-induced apoptosis and matrix turnover factor involved in several neuronal disorders and inflammatory diseases. Evidence has shown linkage disequilibrium between rs3755724 (-55C/T) of this gene with synapsin 2 (SYN2) rs3773364 and peroxisome proliferator-activated G receptor (PPARG) rs2920502 loci, which contribute to epilepsy in Caucasians. The aim of this study was to examine the association of these loci alone or their haplotypes with the risk of epilepsy in the Malaysian population. Genomic DNA of 1241 Malaysian Chinese, Indian, and Malay subjects (670 patients with epilepsy and 571 healthy individuals) was genotyped for the candidate loci by using the Sequenom MassArray method. Allele and genotype association of rs3755724 with susceptibility to epilepsy was significant in the Malaysian Chinese with focal epilepsy under codominant and dominant models (C vs. T: 1.5 (1.1-2.0), p=0.02; CT vs. TT: 1.8 (1.2-2.8), p=0.007 and 1.8 (1.2-2.7), p=0.006, respectively). The T allele and the TT genotype were more common in patients than in controls. No significant association was found between rs2920502 and rs3773364-rs3755724-rs2920502 haplotypes for susceptibility to epilepsy in each ethnicity. This study provides evidence that the promoter TIMP4 rs3755724 is a new focal epilepsy susceptibility variant that is plausibly involved in inflammation-induced seizures in Malaysian Chinese.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  5. Shen X, Howard DM, Adams MJ, Hill WD, Clarke TK, Major Depressive Disorder Working Group of the Psychiatric Genomics Consortium, et al.
    Nat Commun, 2020 05 08;11(1):2301.
    PMID: 32385265 DOI: 10.1038/s41467-020-16022-0
    Depression is a leading cause of worldwide disability but there remains considerable uncertainty regarding its neural and behavioural associations. Here, using non-overlapping Psychiatric Genomics Consortium (PGC) datasets as a reference, we estimate polygenic risk scores for depression (depression-PRS) in a discovery (N = 10,674) and replication (N = 11,214) imaging sample from UK Biobank. We report 77 traits that are significantly associated with depression-PRS, in both discovery and replication analyses. Mendelian Randomisation analysis supports a potential causal effect of liability to depression on brain white matter microstructure (β: 0.125 to 0.868, pFDR 
    Matched MeSH terms: Genetic Predisposition to Disease/genetics
  6. Kabbani T, Abdullah N, Rsheadat Y, Hassan MI
    J Orofac Orthop, 2017 Jan;78(1):62-69.
    PMID: 27896416 DOI: 10.1007/s00056-016-0064-y
    PURPOSE: This research is designed to obtain a better understanding and provide more insight of this phenomenon through evaluating the prevalence of congenital absence of maxillary lateral incisors in a Syrian population.

    METHODS: The method involved clinical examination of 8000 school children with an equal number of males and females (age range 12-15 years) to identify students only affected by bilateral or unilateral congenital absence of maxillary lateral incisors. Agenesis was determined based on radiological evidence.

    RESULTS: The results of this study showed that the prevalence of isolated maxillary lateral incisors agenesis was 1.15%. In the sample studied, 66.3% of the patients were female and 33.7% were male (p 

    Matched MeSH terms: Genetic Predisposition to Disease/genetics
  7. Mohammed Basabaeen AA, Abdelgader EA, Babekir EA, Abdelrahim SO, Eltayeb NH, Altayeb OA, et al.
    Asian Pac J Cancer Prev, 2019 May 25;20(5):1579-1585.
    PMID: 31128065
    Objective: This study aimed at exploring the association of TP53 72Arg/Pro polymorphism and Risk of Chronic
    Lymphocytic Leukemia and to assess the correlation between TP53 72Arg/Pro polymorphism and clinical parameter,
    hematological profile and some biological prognostic markers among Sudanese patients with chronic lymphocytic
    leukemia. Methods: A case-control study was conducted in Khartoum state, Sudan, during the period from April 2017 to
    April 2018, involved 110 B-CLL patients and 80 healthy volunteers as a control group. Physical examination, Complete
    Blood Count and Immunophenotype were performed in all patients to confirm the diagnosis. Clinical staging such as
    Rai and Binet were studied. CD38 and ZAP70 were performed by Flow Cytometry. Blood samples were collected from
    all participants; DNA was extracted by using ANALYTIKJENA Blood DNA Extraction Kit (Germany) and analyzed
    TP53 codon 72Arg/Pro Polymorphism by using AS-PCR. The statistical analysis was performed using SPSS version
    23.0 software (Chicago, IL, USA). Results: the Arg/Pro was the most frequent genotype in B-CLL patients(50%),
    followed by Arg/Arg (25.5%) and Pro/Pro (24.5%), whereas in healthy control group Arg/Pro was the most frequent
    (47.5%), followed by Arg/Arg (45%) and Pro/Pro (7.5%). Our data indicate a higher frequency of homozygous Pro/
    Pro in the B-CLL patients as compared to controls with an OR of 4.01 for the Pro/Pro genotype and lower frequency
    of Arg/Arg genotype in CLL patients as compared to controls with an OR of .42 for the Arg/Arg genotype. Also, the
    Pro allele showed higher risk than Arg allele (P value=0.000, OR 2.23, 95% CI=1.45-3.41). No significant association
    between gender, clinical staging systems (Rai, Binet), biological prognostic markers (CD38 expression or ZAP70
    expression), and TP53 codon 72Arg/Pro polymorphisms, except Arg/Arg genotype tended to be associated with younger
    age (P =0.04). Conclusion: Our data suggested that Pro/Pro genotype contribute to increased susceptibility to B-Chronic
    Lymphocytic Leukemia risk in our population tenfold higher than those had Arg/Arg genotype.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  8. Foo JN, Chew EGY, Chung SJ, Peng R, Blauwendraat C, Nalls MA, et al.
    JAMA Neurol, 2020 06 01;77(6):746-754.
    PMID: 32310270 DOI: 10.1001/jamaneurol.2020.0428
    Importance: Large-scale genome-wide association studies in the European population have identified 90 risk variants associated with Parkinson disease (PD); however, there are limited studies in the largest population worldwide (ie, Asian).

    Objectives: To identify novel genome-wide significant loci for PD in Asian individuals and to compare genetic risk between Asian and European cohorts.

    Design Setting, and Participants: Genome-wide association data generated from PD cases and controls in an Asian population (ie, Singapore/Malaysia, Hong Kong, Taiwan, mainland China, and South Korea) were collected from January 1, 2016, to December 31, 2018, as part of an ongoing study. Results were combined with inverse variance meta-analysis, and replication of top loci in European and Japanese samples was performed. Discovery samples of 31 575 individuals passing quality control of 35 994 recruited were used, with a greater than 90% participation rate. A replication cohort of 1 926 361 European-ancestry and 3509 Japanese samples was analyzed. Parkinson disease was diagnosed using UK Parkinson's Disease Society Brain Bank Criteria.

    Main Outcomes and Measures: Genotypes of common variants, association with disease status, and polygenic risk scores.

    Results: Of 31 575 samples identified, 6724 PD cases (mean [SD] age, 64.3 [10] years; age at onset, 58.8 [10.6] years; 3472 [53.2%] men) and 24 851 controls (age, 59.4 [11.4] years; 11 030 [45.0%] men) were analyzed in the discovery study. Eleven genome-wide significant loci were identified; 2 of these loci were novel (SV2C and WBSCR17) and 9 were previously found in Europeans. Replication in European-ancestry and Japanese samples showed robust association for SV2C (rs246814; odds ratio, 1.16; 95% CI, 1.11-1.21; P = 1.17 × 10-10 in meta-analysis of discovery and replication samples) but showed potential genetic heterogeneity at WBSCR17 (rs9638616; I2=67.1%; P = 3.40 × 10-3 for hetereogeneity). Polygenic risk score models including variants at these 11 loci were associated with a significant improvement in area under the curve over the model based on 78 European loci alone (63.1% vs 60.2%; P = 6.81 × 10-12).

    Conclusions and Relevance: This study identified 2 apparently novel gene loci and found 9 previously identified European loci to be associated with PD in this large, meta-genome-wide association study in a worldwide population of Asian individuals and reports similarities and differences in genetic risk factors between Asian and European individuals in the risk for PD. These findings may lead to improved stratification of Asian patients and controls based on polygenic risk scores. Our findings have potential academic and clinical importance for risk stratification and precision medicine in Asia.

    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  9. Chauhan I, Beena VT, Srinivas L, Sathyan S, Banerjee M
    J Interferon Cytokine Res, 2013 Aug;33(8):420-7.
    PMID: 23651237 DOI: 10.1089/jir.2012.0115
    Oral lichen planus (OLP) is a chronic mucocutaneous condition that affects the oral mucous membrane as well as skin. It is a chronic cell-mediated autoimmune condition where the T-cell-mediated immune response plays an important part in the pathogenesis by causing damage to basal keratinocytes in oral mucosa. Cytokine gene polymorphisms have an unquestionable role in the orchestration of the immune response, leading to different functional scenarios, which in turn influence the outcome of the disease establishment and evolution. The purpose of this study was to understand the role of these cytokine gene polymorphisms in the tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 genes with OLP in 101 individuals of Malayalam-speaking ethnicity from South India (Kerala). We further investigated the role of these polymorphisms in patients suffering from OLP with other comorbid factors. Genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism. The results demonstrate that the A allele in the TNF-α -308 polymorphism could play an important role in the susceptibility to OLP. IL-1β +3954 in OLP was associated with other comorbid factors in both allelic and genotypic combinations. However, when patients suffering from OLP were stratified to understand the involvement of other comorbid factors, we observed that the T and C alleles were independent risk factors for chronic periodontitits and diabetes mellitus. On the other hand, IL-6 -597 did not show any disease association with OLP in the study population. This study indicates that proinflammatory cytokines are an important factor in understanding the disease burden of OLP and their comorbid factors.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  10. Mohd-Yusuf Y, Phipps ME, Chow SK, Yeap SS
    Immunol Lett, 2011 Sep 30;139(1-2):68-72.
    PMID: 21658414 DOI: 10.1016/j.imlet.2011.05.001
    We investigated the association of the HLA genes in Malaysian patients with systemic lupus erythematosus (SLE) and their associations with the clinical manifestations in 160 SLE patients (99 Chinese and 61 Malays) and 107 healthy control individuals (58 Chinese and 49 Malays) were studied. Sequence specific primer amplification (PCR-SSP) phototyping techniques were used to analyse 25 HLA-A allele groups, 31 HLA-DR allele groups and 9 HLA-DQ allele groups. Appreciable increases in allele frequencies of HLA-A*11, DRB1*0701, DRB1*1601-1606, DRB5*01-02 and DQB1*05, and decrease in HLA-DRB1*1101-1121, 1411, DRB1*1201-3, DRB1*1301-22, DRB3*0101, 0201, 0202, 0203, 0301 and DQB1*0301, 1304 in SLE patients compared with healthy control individuals. However, after Bonferroni correction (p(c)<0.05) only HLA-A*1101, 1102, DRB5*01-02, DQB1*05, DRB1*1201-3, DRB3*0101, 0201, 0202, 0203, 0301 and DQB1*0301, 0304 remained significant. Allele frequencies of DRB1*0701 and DRB4*0101101, 0102, 0103, DQB1*05, DRB1*1301-22, DRB3*0101, 0201, 0202, 0203, 0301 and DQB1*0301, 0304 were significantly increased in Malay SLE patients compared with healthy control individuals. In contrast, Chinese SLE patients had increased allele frequencies of DRB1*1601-1606, DQB1*05, DRB1*1201-3, DRB3*0101, 0201, 0202, 0203, 0301, DRB3*0101, 0201, 0202, 0203, 0301 and DQB1*0301, 0304 compared with healthy control individuals. HLA-A*6801-02 and DRB1*1601-1606 frequencies appeared elevated in a subset of patients with serositis and DRB1* 0401-1122 frequency was elevated in those displaying neurologic disorder. However, unequivocal evidence of these associations would require investigation of substantially larger cohorts. On the whole, our findings suggest that HLA allele associations with SLE are race specific in Malays and Chinese.
    Study site: SLE clinic, University of Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
    Matched MeSH terms: Genetic Predisposition to Disease/genetics
  11. Couch FJ, Kuchenbaecker KB, Michailidou K, Mendoza-Fandino GA, Nord S, Lilyquist J, et al.
    Nat Commun, 2016 Apr 27;7:11375.
    PMID: 27117709 DOI: 10.1038/ncomms11375
    Common variants in 94 loci have been associated with breast cancer including 15 loci with genome-wide significant associations (P<5 × 10(-8)) with oestrogen receptor (ER)-negative breast cancer and BRCA1-associated breast cancer risk. In this study, to identify new ER-negative susceptibility loci, we performed a meta-analysis of 11 genome-wide association studies (GWAS) consisting of 4,939 ER-negative cases and 14,352 controls, combined with 7,333 ER-negative cases and 42,468 controls and 15,252 BRCA1 mutation carriers genotyped on the iCOGS array. We identify four previously unidentified loci including two loci at 13q22 near KLF5, a 2p23.2 locus near WDR43 and a 2q33 locus near PPIL3 that display genome-wide significant associations with ER-negative breast cancer. In addition, 19 known breast cancer risk loci have genome-wide significant associations and 40 had moderate associations (P<0.05) with ER-negative disease. Using functional and eQTL studies we implicate TRMT61B and WDR43 at 2p23.2 and PPIL3 at 2q33 in ER-negative breast cancer aetiology. All ER-negative loci combined account for ∼11% of familial relative risk for ER-negative disease and may contribute to improved ER-negative and BRCA1 breast cancer risk prediction.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  12. Guo X, Long J, Zeng C, Michailidou K, Ghoussaini M, Bolla MK, et al.
    Cancer Epidemiol Biomarkers Prev, 2015 Nov;24(11):1680-91.
    PMID: 26354892 DOI: 10.1158/1055-9965.EPI-15-0363
    BACKGROUND: A recent association study identified a common variant (rs9790517) at 4q24 to be associated with breast cancer risk. Independent association signals and potential functional variants in this locus have not been explored.

    METHODS: We conducted a fine-mapping analysis in 55,540 breast cancer cases and 51,168 controls from the Breast Cancer Association Consortium.

    RESULTS: Conditional analyses identified two independent association signals among women of European ancestry, represented by rs9790517 [conditional P = 2.51 × 10(-4); OR, 1.04; 95% confidence interval (CI), 1.02-1.07] and rs77928427 (P = 1.86 × 10(-4); OR, 1.04; 95% CI, 1.02-1.07). Functional annotation using data from the Encyclopedia of DNA Elements (ENCODE) project revealed two putative functional variants, rs62331150 and rs73838678 in linkage disequilibrium (LD) with rs9790517 (r(2) ≥ 0.90) residing in the active promoter or enhancer, respectively, of the nearest gene, TET2. Both variants are located in DNase I hypersensitivity and transcription factor-binding sites. Using data from both The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), we showed that rs62331150 was associated with level of expression of TET2 in breast normal and tumor tissue.

    CONCLUSION: Our study identified two independent association signals at 4q24 in relation to breast cancer risk and suggested that observed association in this locus may be mediated through the regulation of TET2.

    IMPACT: Fine-mapping study with large sample size warranted for identification of independent loci for breast cancer risk.

    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  13. Zhang M, Wang Z, Obazee O, Jia J, Childs EJ, Hoskins J, et al.
    Oncotarget, 2016 Oct 11;7(41):66328-66343.
    PMID: 27579533 DOI: 10.18632/oncotarget.11041
    Genome-wide association studies (GWAS) have identified common pancreatic cancer susceptibility variants at 13 chromosomal loci in individuals of European descent. To identify new susceptibility variants, we performed imputation based on 1000 Genomes (1000G) Project data and association analysis using 5,107 case and 8,845 control subjects from 27 cohort and case-control studies that participated in the PanScan I-III GWAS. This analysis, in combination with a two-staged replication in an additional 6,076 case and 7,555 control subjects from the PANcreatic Disease ReseArch (PANDoRA) and Pancreatic Cancer Case-Control (PanC4) Consortia uncovered 3 new pancreatic cancer risk signals marked by single nucleotide polymorphisms (SNPs) rs2816938 at chromosome 1q32.1 (per allele odds ratio (OR) = 1.20, P = 4.88x10 -15), rs10094872 at 8q24.21 (OR = 1.15, P = 3.22x10 -9) and rs35226131 at 5p15.33 (OR = 0.71, P = 1.70x10 -8). These SNPs represent independent risk variants at previously identified pancreatic cancer risk loci on chr1q32.1 ( NR5A2), chr8q24.21 ( MYC) and chr5p15.33 ( CLPTM1L- TERT) as per analyses conditioned on previously reported susceptibility variants. We assessed expression of candidate genes at the three risk loci in histologically normal ( n = 10) and tumor ( n = 8) derived pancreatic tissue samples and observed a marked reduction of NR5A2 expression (chr1q32.1) in the tumors (fold change -7.6, P = 5.7x10 -8). This finding was validated in a second set of paired ( n = 20) histologically normal and tumor derived pancreatic tissue samples (average fold change for three NR5A2 isoforms -31.3 to -95.7, P = 7.5x10 -4-2.0x10 -3). Our study has identified new susceptibility variants independently conferring pancreatic cancer risk that merit functional follow-up to identify target genes and explain the underlying biology.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  14. Coleman JRI, Peyrot WJ, Purves KL, Davis KAS, Rayner C, Choi SW, et al.
    Mol Psychiatry, 2020 Jul;25(7):1430-1446.
    PMID: 31969693 DOI: 10.1038/s41380-019-0546-6
    Depression is more frequent among individuals exposed to traumatic events. Both trauma exposure and depression are heritable. However, the relationship between these traits, including the role of genetic risk factors, is complex and poorly understood. When modelling trauma exposure as an environmental influence on depression, both gene-environment correlations and gene-environment interactions have been observed. The UK Biobank concurrently assessed Major Depressive Disorder (MDD) and self-reported lifetime exposure to traumatic events in 126,522 genotyped individuals of European ancestry. We contrasted genetic influences on MDD stratified by reported trauma exposure (final sample size range: 24,094-92,957). The SNP-based heritability of MDD with reported trauma exposure (24%) was greater than MDD without reported trauma exposure (12%). Simulations showed that this is not confounded by the strong, positive genetic correlation observed between MDD and reported trauma exposure. We also observed that the genetic correlation between MDD and waist circumference was only significant in individuals reporting trauma exposure (rg = 0.24, p = 1.8 × 10-7 versus rg = -0.05, p = 0.39 in individuals not reporting trauma exposure, difference p = 2.3 × 10-4). Our results suggest that the genetic contribution to MDD is greater when reported trauma is present, and that a complex relationship exists between reported trauma exposure, body composition, and MDD.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  15. Wei LK, Sutherland H, Au A, Camilleri E, Haupt LM, Gan SH, et al.
    Biomed Res Int, 2015;2015:167976.
    PMID: 25705649 DOI: 10.1155/2015/167976
    Stroke is a multifactorial disease that may be associated with aberrant DNA methylation profiles. We investigated epigenetic dysregulation for the methylenetetrahydrofolate reductase (MTHFR) gene among ischemic stroke patients. Cases and controls were recruited after obtaining signed written informed consents following a screening process against the inclusion/exclusion criteria. Serum vitamin profiles (folate, vitamin B12, and homocysteine) were determined using immunoassays. Methylation profiles for CpGs A and B in the MTHFR gene were determined using a bisulfite-pyrosequencing method. Methylation of MTHFR significantly increased the susceptibility risk for ischemic stroke. In particular, CpG A outperformed CpG B in mediating serum folate and vitamin B12 levels to increase ischemic stroke susceptibility risks by 4.73-fold. However, both CpGs A and B were not associated with serum homocysteine levels or ischemic stroke severity. CpG A is a potential epigenetic marker in mediating serum folate and vitamin B12 to contribute to ischemic stroke.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics
  16. Sam SS, Teoh BT, Chinna K, AbuBakar S
    Int J Med Sci, 2015;12(2):177-86.
    PMID: 25589894 DOI: 10.7150/ijms.8988
    Dengue virus (DENV) infection usually presents with mild self-limiting dengue fever (DF). Few however, would present with the more severe form of the disease, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). In the present study, the association between IL-12B, IL-10 and TNF-α gene polymorphisms and dengue severity was investigated.
    METHODS: A case-control study was performed on a total of 120 unrelated controls, 86 DF patients and 196 DHF/DSS patients. The polymorphisms in IL-12B, IL-10 and TNF-α genes were genotyped using PCR-RFLP and PCR-sequencing methods.
    RESULTS: A protective association of TNF-α -308A allele and -308GA genotype against DHF/DSS was observed, while TNF-α -238A allele and -238GA genotype were associated with DHF/DSS. A combination of TNF-α -308GA+AA genotype and IL-10 non-GCC haplotypes, IL-12B pro homozygotes (pro1/pro1, pro2/pro2) and IL-12B 3'UTR AC were significantly correlated with protective effects against DHF/DSS. An association between the cytokine gene polymorphisms and protection against the clinical features of severe dengue including thrombocytopenia and increased liver enzymes was observed in this study.
    CONCLUSION: The overall findings of the study support the correlation of high-producer TNF-α genotypes combined with low-producer IL-10 haplotypes and IL-12B genotypes in reduced risk of DHF/DSS.
    KEYWORDS: Infectious disease; cytokine; dengue; genetics; polymorphism.; tropical
    Matched MeSH terms: Genetic Predisposition to Disease/genetics
  17. Lee CC, Harun F, Jalaludin MY, Heh CH, Othman R, Junit SM
    BMJ Open, 2015 Jan 05;5(1):e006121.
    PMID: 25564141 DOI: 10.1136/bmjopen-2014-006121
    OBJECTIVES: The c.2268dup mutation in the thyroid peroxidase (TPO) gene is the most common TPO alteration reported in Taiwanese patients with thyroid dyshormonogenesis. The ancestors of these patients are believed to originate from the southern province of China. Our previous study showed that this mutation leads to reduced abundance of the TPO protein and loss of TPO enzyme activity in a Malaysian-Chinese family with goitrous hypothyroidism. The aim of our study was to provide further data on the incidence of the c.2268dup mutation in a cohort of Malaysian-Chinese and its possible phenotypic effects.

    SETTING: Cohort study.

    PARTICIPANTS: Twelve biologically unrelated Malaysian-Chinese patients with congenital hypothyroidism were recruited in this study. All patients showed high thyrotropin and low free thyroxine levels at the time of diagnosis with proven presence of a thyroid gland.

    PRIMARY OUTCOME MEASURE: Screening of the c.2268dup mutation in the TPO gene in all patients was carried out using a PCR-direct DNA sequencing method.

    SECONDARY OUTCOME MEASURE: Further screening for mutations in other exonic regions of the TPO gene was carried out if the patient was a carrier of the c.2268dup mutation.

    RESULTS: The c.2268dup mutation was detected in 4 of the 12 patients. Apart from the c.2268dup and a previously documented mutation (c.2647C>T), two novel TPO alterations, c.670_672del and c.1186C>T, were also detected in our patients. In silico analyses predicted that the novel alterations affect the structure/function of the TPO protein.

    CONCLUSIONS: The c.2268dup mutation was detected in approximately one-third of the Malaysian-Chinese patients with thyroid dyshormonogenesis. The detection of the novel c.670_672del and c.1186C>T alterations expand the mutation spectrum of TPO associated with thyroid dyshormonogenesis.

    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  18. Chua YA, Abdullah WZ, Yusof Z, Gan SH
    Biomed Res Int, 2014;2014:316310.
    PMID: 24790995 DOI: 10.1155/2014/316310
    The vitamin K epoxide reductase complex 1 gene (VKORC1) is commonly assessed to predict warfarin sensitivity. In this study, a new nested allele-specific multiplex polymerase chain reaction (PCR) method that can simultaneously identify single nucleotide polymorphisms (SNPs) at VKORC1 381, 861, 5808, and 9041 for haplotype analysis was developed and validated. Extracted DNA was amplified in the first PCR DNA, which was optimized by investigating the effects of varying the primer concentrations, annealing temperature, magnesium chloride concentration, enzyme concentration, and the amount of DNA template. The amplification products produced from the first round of PCR were used as templates for a second PCR amplification in which both mutant and wild-type primers were added in separate PCR tubes, followed by optimization in a similar manner. The final PCR products were resolved by agarose gel electrophoresis and further analysed by using a VKORC1 genealogic tree to infer patient haplotypes. Fifty patients were identified to have H1H1, one had H1H2, one had H1H7, 31 had either H1H7 or H1H9, one had H1H9, eight had H7H7, and one had H8H9 haplotypes. This is the first method that is able to infer VKORC1 haplotypes using only conventional PCR methods.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  19. Rohana AG, Loh KC, Tin SK, Soh CH, Nazaimoon WM, Fong KY, et al.
    Med J Malaysia, 2011 Jun;66(2):133-7.
    PMID: 22106694
    HLA-DQA1, -DQB1, and -DRB1 gene polymorphism were analyzed to study type 1 DM susceptibility in Malay patients from Southeast Asia (Malaysia and Singapore). Patients showed significant increases in the occurrence of DQA1*0501 (50.7% vs. 20.4%; RR = 3.97; Pc < 0.01), DQB1*0201 (48% vs. 19.1%; RR = 3.86; Pc < 0.05), and DRB1*0301 (38.7 vs. 6.8%; RR = 8.36; 95% Pc < 0.05). Conversely, significant decreases were noted in the occurrence of DQA1*0601 (14.7% vs. 35.2%; RR = 0.33; Pc = 0.008) and DQB1*0601 (4% vs. 23.5%; RR = 0.16; Pc < 0.05) in type 1 DM patients. Using a logistic regression model, we derived a risk prediction model for type 1 DM in our indigenous Malay population based on the identified HLA genotypes. The RR for type 1 DM increases by a factor of 5.68 for every unit increase in the number of DRB1*0301 allele (P < 0.001), and decreases by a factor of 0.18 per unit increase in the number of DQB1*0601 allele (P < 0.001). After adjusting for these two HLA genotypes, DQA1*0501, DQB1*0201 and DQA1*0601 were not statistically significant as risk predictors. The lower incidence of type 1 DM in the Malay population may be contributed by the genotypic combinations of DR and DQ genes as well as the linkage disequilibria between susceptible and protective alleles.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics*
  20. Ku CS, Teo SM, Naidoo N, Sim X, Teo YY, Pawitan Y, et al.
    J Hum Genet, 2011 Aug;56(8):552-60.
    PMID: 21677662 DOI: 10.1038/jhg.2011.54
    Copy number variations can be identified using newer genotyping arrays with higher single nucleotide polymorphisms (SNPs) density and copy number probes accompanied by newer algorithms. McCarroll et al. (2008) applied these to the HapMap II samples and identified 1316 copy number polymorphisms (CNPs). In our study, we applied the same approach to 859 samples from three Singapore populations and seven HapMap III populations. Approximately 50% of the 1291 autosomal CNPs were found to be polymorphic only in populations of non-African ancestry. Pairwise comparisons among the 10 populations showed substantial differences in the CNPs frequencies. Additionally, 698 CNPs showed significant differences with false discovery rate (FDR)<0.01 among the 10 populations and these loci overlap with known disease-associated or pharmacogenetic-related genes such as CFHR3 and CFHR1 (age related macular degeneration), GSTTI (metabolism of various carcinogenic compounds and cancers) and UGT2B17 (prostate cancer and graft-versus-host disease). The correlations between CNPs and genome-wide association studies-SNPs were investigated and several loci, which were previously unreported, that may potentially be implicated in complex diseases and traits were found; for example, childhood acute lymphoblastic leukaemia, age-related macular degeneration, breast cancer, response to antipsychotic treatment, rheumatoid arthritis and type-1 diabetes. Additionally, we also found 5014 novel copy number loci that have not been reported previously by McCarroll et al. (2008) in the 10 populations.
    Matched MeSH terms: Genetic Predisposition to Disease/genetics
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