Evaluation of Type 2 Diabetes Risk Variants (Alleles) in the Pashtun Ethnic Population of Pakistan.

Objective: To evaluate the Type 2 Diabetes (T2D) risk variants in the Pashtun ethnic population of Khyber Pakhtunkhwa using nascent whole-exome sequencing (WES) to better understand the pathogenesis of this complex polygenic disorder. Methodology: A total of 100 confirmed patients with T2D of Pashtun ethnicity were included in the study, DNA was extracted from whole blood samples, and paired-end libraries were prepared using the Illumina Nextera XT DNA library kit carefully following the manufacturer's instructions. Illumina HiSeq 2000 was used to obtain sequences of the prepared libraries followed by bioinformatics data analysis. Results: A total of n=11 pathogenic/likely pathogenic variants were reported in the CAP10, PAX4, IRS-2, NEUROD1, CDKL1 and WFS1. Among the reported variants CAP10/rs55878652 (c.1990-7T>C; p.Leu446Pro) and CAP10/rs2975766 (c.1996A>G; p.Ile666Val) identified were novel, and have not yet been reported for any disease in the database.The variants CAP10/rs7607759 (c.1510A>G, p.Thr504Ala), PAX4/rs712701 (c.962A>C; p.His321Pro), PAX4/rs772936097 (c.748-3delT; p.Arg325Trp), IRS-2/rs1805097 (c.3170G>A; p.Gly1057Asp), NEUROD1/rs1801262 (c.133A>G; p.Thr45Ala), CDKL1/rs77152992 (c.1226C>T; p.Pro409Leu), WFS1/rs1801212 (c.997G>A; p.Val333Ile), WFS1/rs1801208 (c.1367G>A; p.Arg456His), and WFS1/rs734312 (c.1832G>A; p.Arg611His) are previously identified in other ethnic populations. Our study reconfirms the associations of these variants with T2D in the Pakistani Pashtun population. Conclusion: In-silico analysis of exome sequencing data suggests a statistically substantial association of all (n=11) identified variants with T2D in the Pashtun ethnic population. This study may serve as a foundation for performing future molecular studies aimed at unraveling T2D associated genes.

Single Nucleotide Polymorphism at rs7903146 of Transcription Factor 7-like 2 gene Among Subjects with Type 2 Diabetes Mellitus in Myanmar.

Objectives: To investigate the association between the single nucleotide polymorphism (SNP) rs7903146 in the transcription factor 7-like 2 (TCF7L2) gene and type 2 diabetes mellitus (T2DM) and to examine the impact of this variant on pancreatic beta-cell function in the Myanmar population. Methodology: A case-control study was undertaken in 100 subjects with T2DM and 113 controls. The SNP rs7903146 was genotyped using the allele-specific polymerase chain reaction method. Plasma glucose and serum insulin levels were determined using the enzymatic colorimetric method and ELISA respectively. Beta-cell function was calculated by the HOMA-ß formula. Results: The frequencies of carrier genotypes (CT and TT) were higher in subjects with T2DM than in controls. The minor T alleles of rs7903146 were found to statistically increase type 2 diabetes risk than the C allele with an allelic odds ratio of 2.07 (95% CI 1.39-3.09, p=0.0004). The mean HOMA-ß level of the group with non-carrier genotype (CC) was significantly higher than that of the groups with carrier genotypes (CT and TT) in subjects with T2DM and controls with a p-value of 0.0003 and less than 0.0001, respectively. Conclusion: The rs7903146 variant of the TCF7L2 gene was found to be associated with T2DM and low ß-cell function among Myanmar subjects.

Validation of Genome-Wide Association Studies (GWAS)-Identified Type 2 Diabetes Mellitus Risk Variants in Pakistani Pashtun Population.

Objective: Recent GWAS largely conducted in European populations have successfully identified multiple genetic risk variants associated with Type 2 Diabetes Mellitus (T2DM). However, the effects conferred by these variants in the Pakistani population have not yet been fully elucidated. The objective of this study was to examine European GWAS-identified T2DM risk variants in the Pakistani Pashtun population to better understand the shared genetic basis of T2DM in the European and Pakistani cohorts. Methodology: A total of 100 T2DM patients and 100 healthy volunteers of Pashtun ethnicity were enrolled in this study. Both groups were genotyped for 8 selected single nucleotide polymorphisms (SNPs) using the Sequenom MassARRAY® platform. The association between selected SNPs and T2DM was determined by using appropriate statistical tests. Results: Of the 8 studied SNPs, 5 SNPs, SLC30A8/ rs13266634 (p=0.031, OR=2.13), IGF2BP2/ rs4402960 (p=0.001, OR=3.01), KCNJ11/ rs5219 (p=0.042, OR=1.78), PPARG/ rs1801282 (p=0.042, OR=2.81) and TCF7L2/ rs7903146 (p=0.00006, 3.41) had a significant association with T2DM. SNP GLIS3/ rs7041847 (p=0.051, OR=2.01) showed no sufficient evidence of association. SNPs KCNQ1/ rs2237892 (p=0.140, OR=1.61) and HHEX/IDE/ s1111875 (p=0.112, OR=1.31) showed opposite allelic effects and were not validated for T2DM risk in the study population. Among the studied SNPs, TCF7L2/ rs7903146 showed the most significant association. Conclusion: Our study finding indicates that selected genome-wide significant T2DM risk variants previously identified in European descent also increase the risk of developing T2DM in the Pakistani Pashtun population.

Association of APOE (rs429358 and rs7412) and PON1 (Q192R and L55M) Variants with Myocardial Infarction in the Pashtun Ethnic Population of Khyber Pakhtunkhwa, Pakistan.

Coronary Artery Diseases (CAD) remains the top among Non-communicable Diseases (NCDs). Variations in Apolipoprotein E (APOE) and Paroxonase 1 (PON1) have been associated with Myocardial Infarction (MI) in several populations. However, despite the high prevalence of CAD, no such study has been reported in the Pashtun ethnic population of Pakistan. We have conducted a two-stage (i.e., screening and validation) case-control study in which 200 cases and 100 control subjects have been recruited. In the first stage, Whole Exome Sequencing (WES) was used to screen for pathogenic variants of Myocardial Infarction (MI). In the second stage, selected variants of both APOE and PON1 genes (rs7412, rs429358, rs854560, and rs662) were analyzed through MassARRAY genotyping. Risk Allele Frequencies (RAFs) distribution and association of the selected SNPs with MI were determined using the Chi-square test and logistic regression analysis. WES identified a total of 12 sequence variants in APOE and 16 in PON1. Genotyping results revealed that APOE variant rs429358 (ɛ4 allele and ɛ3/ɛ4 genotype) showed significant association in MI patients (OR = 2.11, p value = 0.03; 95% CI = 1.25-2.43); whereas no significant difference (p˃ 0.05) was observed for rs7412. Similarly, the R allele of PON1 Q192R (rs662) was significantly associated with cases (OR = 1.353, p value = 0.048; 95% CI = 0.959-1.91), with particular mention of RR genotype (OR = 1.523, p value = 0.006; 95% CI = 1.087-2.132). Multiple logistic regression analysis showed that rs429358 (C allele) and rs662 (R allele) have a significantly higher risk of MI after adjustment for the conventional risk factors. Our study findings suggested that the rs429358 variant of APOE and PON1 Q192R are associated with MI susceptibility in the Pashtun ethnic population of Pakistan.