Role of C677T and A1298C MTHFR, A2756G MTR and-786 C/T eNOS Gene Polymorphisms in Atrial Fibrillation Susceptibility

Background. Hyperhomocysteinemia has been suggested to play a role in the NonValvular Atrial Fibrillation (NVAF) pathogenesis. Polymorphisms in genes coding for homocysteine (Hcy) metabolism enzymes may be associated with hyperhomocysteinemia and NVAF. Methodologies. 456 NVAF patients and 912 matched controls were genotyped by an electronic microchip technology for C677T and A1298C MTHFR, A2756G MTR, and -786C/T eNOS gene polymorphisms. Hcy was determined by an immunoassay method. Principal Findings. The genotype distribution of the four polymorphisms as well as genotype combinations did not differ in patients and controls. Hcy was higher in patients than in controls (15.2, 95% CI 14.7-15.7 vs 11.3, 95% CI 11.0-11.6 mu mol/L; p<0.0001). In both populations, a genotype-phenotype association (p, 0.0001) between Hcy and C677T MTHFR polymorphism was observed; in controls a significant (p = 0.029) association between tHcy and -786C/T eNOS polymorphism was also observed. At the multivariate analysis the NVAF risk significantly increased in the upper quartiles of Hcy compared to the lowest: OR from 2.8 (1.68-4.54 95% CI) in Q2 to 12.9 (7.96-21.06 95% CI) in Q4. Conclusions. Our data demonstrated the four polymorphisms, although able, at least in part, to affect Hcy, were not associated with an increased risk of NVAF per se or in combination.