The relationship of the methylenetetrahydrofolate reductase C677T gene polymorphism in Turkish type 2 diabetic patients with and without nephropathy

Background Poor glycaemic control, hypertension and duration of diabetes are risk factors for the development of diabetic nephropathy, but there may be genetic factors. Recently, a common C to T mutation at nucleotide position 677 of the MTHFR gene (MTHFR677C>T) has been reported to be correlated with hyperhomocysteinemia and the severity of coronary artery disease as macroangiopathy. We aim to investigate Turkish type 2 diabetic patients with/without diabetic nephropathy and healthy group and examine the contribution of the MTHFR gene polymorphism to the development of diabetic nephropathy. Methods DNA was extracted from peripheral leukocytes of the subjects. Genotyping of the MTHFR C677T polymorphism for all individuals was performed by melting curve analysis of the generated amplicons after realtime online PCR. Results This genotype distribution did not differ between control subjects and type 2 diabetic patients in which 6.8% were TT, 43.7% were CT and 49.5% were CC (chi(2) = 0.201, p > 0.05). The frequency of the mutant T allele was 23.4% in diabetic patients with nephropathy versus 33.0% in those without nephropathy. The genotype frequencies were TT, 2.1%; CT, 46.6%; CC, 55.3% in diabetic patients with nephropathy versus TT, 10.7%; CT, 44.6%; CC, 44.6% in those without nephropathy. Conclusions The MTHFR genotype and allele frequencies were not different between diabetic patients with and without nephropathy (chi(2) = 3, 386, p > 0.005; chi(2) = 2.320, p > 0.005, respectively). Therefore, we conclude that the MTHFR gene polymorphism is not associated with the development of diabetic nephropathy in Turkish type 2 diabetic patients. Copyright (D 2007 John Wiley & Sons, Ltd.