Significant association of MTHFD1 1958G>A single nucleotide polymorphism with nonsyndromic cleft lip and palate in Indian population

Objectives: Nonsyndromic cleft lip and palate (NSCLP) is genetically distinct from those with syndromic clefts, and accounts for ~70% of cases with Oral clefts. Folate, or vitamin B9, is an essential nutrient in our diet. Allelic variants in genes involved in the folate pathway might be expected to have an impact on risk of oral clefts. Given the key role of methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) in folate metabolism, it would be of significant interest to assess its role in NSCLP etiology. Study Design: The present study aims at examining the association between MTHFD1 1958G>A polymorphism and NSCLP risk by conducting a case-control study in south Indian population. Our sample comprised of 142 cases with nonsyndromic clefts and 141 controls without clefts or family history of clefting. The MTHFD1 1958G>A polymorphism was genotyped using PCR-RFLP. Results: An increased risk was found for the heterozygous 1958GA (OR=2.44; P =0.020) and homozygous 1958AA (OR=2.45; P =0.012) genotypes in the children. When the dominant model (AG+AA vs GG) was applied the risk remained the same as co-dominant model, but the level of significance increased (OR=2.44; P =0.002). Conclusions: The results indicated the MTHFD1 1958G>A polymorphism to be one of the important genetic determinants of NSCLP risk in South Indian subjects

Związek między polimorfizmem rs7903146 genu TCF7L2 a nefropatią cukrzycową nie jest niezależny od cukrzycy typu 2 — badanie populacji Indii Południowych i metaanaliza

Diabetic nephropathy (DN) is a chronic microangiopathic complication of both type 1 (T1DM) and type 2 diabetes mellitus (T2DM). The TCF7L2 gene has been reported to be associated with type 2 diabetes risk. We aimed to investigate the impact of TCF7L2 gene on the susceptibility of T2DM and DN in a south Indian population. Plus to evaluate the association of rs7903146 in the TCF7L2 gene with T2DM in the Indian population. The subjects recruited for this included 55 diabetic cases with diabetic nephropathy, 68 diabetic cases without nephropathy, and 82 non-diabetic healthy controls. Genomic DNA was isolated from blood and genotyping of TCF7L2 rs7903146 was performed by PCR-RFLP analysis. A literature survey was carried out into the effect of rs7903146 on genetic susceptibility to T2DM in Indian populations and we then performed a meta-analysis in order to evaluate its association with T2DM. Analysis of TCF7L2 rs7903146 in normal controls and diabetics with or without nephropathy demonstrated that the ‘T’ allele is associated with both diabetes (p = 0.049) and DN (p = 0.024), but this association is not independent of T2DM. Meta-analysis showed that the mutant allele and genotypes are associated with T2DM in Indian populations. In summary, a significant association exists between the ‘T’ allele and DN, but this association is not independent of T2DM. Pooled meta-analysis of studies on rs7903146 and T2DM confirmed that rs7903146 is significantly associated with susceptibility to T2DM in Indian populations. (Endokrynol Pol 2014; 65 (4): 298–305)Nefropatia cukrzycowa (DN, diabetic nephropathy) jest przewlekłym powikłaniem o charakterze mikroangiopatii występującym zarówno w cukrzycy typu 1 (T1DM, type 1 diabetes mellitus), jak i typu 2 (T2DM, type 2 diabetes mellitus). Gen TCF7L2 jest związany z ryzykiem cukrzycy typu 2. Badanie przeprowadzono w celu dokonania oceny wpływu genu TCF7L2 na podatność na zachorowanie na T2DM i DN w populacji Indii Południowych oraz oceny związku między występowaniem polimorfizmu rs7903146 genu TCF7L2 i T2DM w populacji południowej części Indii. Do badania włączono 55 przypadków chorych na cukrzycę z nefropatią cukrzycową, 68 przypadków cukrzycy bez nefropatii i 82 osoby niechorujące na cukrzycę jako grupę kontrolną. Genomowe DNA izolowano z krwi i przeprowadzono genotypowanie polimorfizmu rs7903146 genu TCF7L2 metodą analizy PCR-RFLP. Przeprowadzono również przegląd literatury pod kątem danych dotyczących wpływu występowania polimorfizmu rs7903146 na genetyczną podatność na T2DM w populacji hinduskiej, a następnie przeprowadzono metaanalizę w celu oceny jego związku z T2DM. Analiza polimorfizmu rs7903146 genu TCF7L2 u zdrowych osób z grupy kontrolnej oraz u chorych na cukrzycę z nefropatią i bez nefropatii wykazała, że allel T jest związany zarówno z cukrzycą (p = 0,049), jak i DN (p = 0,024), jednak ten związek nie jest niezależny od T2DM. Metaanaliza wykazała, że zmutowane allele i genotypy są związane z T2DM w populacji hinduskiej. Podsumowując, istnieje istotny związek między allelem T i DN, jednak związek ten nie jest niezależny od T2DM. Metaanaliza danych z badań dotyczących polimorfizmu rs7903146 i T2DM potwierdziła, że obecność polimorfizmu rs7903146 jest istotnie związana z podatnością na zachorowanie na T2DM w populacji hinduskiej. (Endokrynol Pol 2014; 65 (4): 298–305

Lack of association between IRF6 polymorphisms and nonsyndromic oral clefts in South Indian population

Objective: This present study is aimed to investigate the association between interferon regulatory factor 6 (IRF6), single nucleotide polymorphisms (SNPs), and nonsyndromic cleft lip without without cleft palate (NSCLP) in the South Indian population. Subject and Methods: For this study, 190 unrelated NSCLP patients and 189 controls without clefts were genotyped with rs2235371 (V2741) and rs642961 SNPs using PCR-RFLP. The associations between NSCLP groups and IRF6 gene polymorphisms, as well as haplotypes, were analyzed using chi-squared test and 95% confidence interval (95%CI) of the odds ratios were calculated with the control groups as reference. Results: For controls, the minor allele frequencies of both variants, V2741 and rs642961, were 7.1% and 21.1%, respectively. Genotype data for both variants in control and cleft groups follow the Hardy Weinberg Equilibrium. Between cases with NSCLP and controls, the two SNPs showed no differences in frequencies of the genotypes or alleles. The pairwise linkage disequilibrium (LD) values (D’=1 and r2=0.027) between V2741 and rs642961 revealed that these two SNPs are not in strong LD. Haplotype G-T showed a significantly reduced risk for oral clefts (p<0.001) and haplotype A-T increased the risk for oral clefts (p=0.043). Gene-gene interaction showed that the higher risk group contains more GG-CC combination of cases that the controls, but this model was not significantly associated with cleft status (p=0.136) Conclusion: In conclusion, while IRF6 is strongly associated in other populations, this study demonstrated that variants in IRF6 may play a role in NSCLP in a South Indian population, but other genes are expected to play a role in this population as well