Genetic Variant XRCC1 rs1799782 (C194T) and Risk of Cancer Susceptibility in Indian Population: A Meta-analysis of Case–Control Studies

X-ray repair cross-complementing group 1 (XRCC1) plays a key role in the base excision repair pathway, as a scaffold protein that brings together proteins of the DNA repair complex. Several studies have reported contradictory results for XRCC1 exon 6 C>T (rs1799782) gene polymorphism and cancer risk in Indian population has provided inconsistent results. Therefore, we have performed this meta-analysis to evaluate the relationship between XRCC1 exon 6 C>T gene polymorphism and risk of cancer by published studies. We searched PubMed and Google scholar web databases to cover all studies published on association between XRCC1 exon 6 C>T gene polymorphism and cancer risk. The meta-analysis was carried out and pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to appraise the strength of association. In order to derive a more precise estimation of the association, A total of 3197 confirmed cancer cases and 3819 controls were included from eligible seventeen case-controls studies. Results from overall pooled analysis demonstrated suggested that that variant allele (T vs. C: OR 1.301, 95% CI 1.003–1.688, p = 0.047) was associated with the risk of overall cancer. Other genetic models; heterozygous (TC vs. CC: OR 1.108, 95% CI 0.827–1.485, p = 0.491), homozygous (TT vs. CC: OR 1.479, 95% CI 0.877–2.493, p = 0.142), dominant (TT+TC vs. CC: OR 1.228, 95% CI 0.899–1.677, p = 0.196) and recessive (TT vs. TC+CC: OR 1.436, 95% CI 0.970–2.125, p = 0.071) did not reveal statistical association. Publication bias observation was also considered and none was detected during the analysis. The present meta-analysis suggested that the variant allele T of XRCC1 exon 6 gene polymorphism was associated with the risk of cancer. It is therefore pertinent to confirm this finding in a large sample size to divulge the mechanism of this polymorphism and cancer risk in Indian population.     

MTHFR (Ala 222 Val) polymorphism and AMI in patients with type II diabetes mellitus

The prevalent Ala222Val single nucleotide polymorphism of the MTHFR gene has been shown to be associated with type II diabetes. The objective of the present study was to find out whether there is genetic predisposition for development of acute myocardial infarction in type II diabetes mellitus among South Indian Tamil population. PCR-based restriction enzyme analysis was performed in DNA isolated from 120 acute myocardial infarction patients with diabetes mellitus and 100 non diabetic healthy individuals with no documented cardiovascular diseases. The results indicate that the MTHFR 677TT genotype is absent in both case and controls. The MTHFR 677CT genotype was observed among 32 (26.7 %) cases and 20 (20%) controls and the MTHFR 677CC genotype among 88 (73.3%) cases and 80 (80%) controls. The allelic frequencies were in accordance to Hardy Weinberg equilibrium. There was no statistical difference in genotype distribution between cases and controls. In conclusion, we suggest that the analysis of MTHFR genotyping for C677T polymorphism alone need not be considered to find out whether there is genetic predisposition for development of acute myocardial infarction in type II diabetes mellitus among South Indian Tamil population.     

Leucine125Valine (Leu125Val) Gene Polymorphism of Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1) and Myocardial Infarction in Indian Population

Platelet-endothelial cell adhesion molecule-1 (PECAM-1) has role in atherosclerotic plaque development as well as in thrombosis leading to myocardial infarction (MI). Present study was aimed to analyse the association of PECAM-1 Leu125Val gene polymorphism with MI in Indian population. Subjects included healthy individuals as control (N = 116) and MI patients (N = 100) divided into two groups; MI patients at presentation of the acute event (MI-Group-1, N = 46) and patients with recent event of MI stabilized with treatment 4.5 days from their symptoms (MI-Group-2, N = 54). The difference in the distribution of Leu125Val genotype frequencies of controls and patients did not reach statistical significance. However Leu allele frequency (0.57) was more associated with MI patients as compared to control (0.504). sPECAM-1 levels were significantly elevated in patients at acute event of MI (MI-Group-1) by 44.1% (P = 0.009) as compared to controls and by 95.2% (P = 0.001) as compared to stabilized MI patients (MI-Group-2).