MTHFR 677C>T (rs1801133) variant is associated with homocysteinemia but not with clinical severity in patients with peripheral arterial occlusive disease  

The aim of this study was to evaluate the association between the MTHFR 677C > T (rs1801133) genetic variant with susceptibility and severity of peripheral arterial occlusive disease (PAOD) and with serum levels of homocysteine (Hcy). This case-control study enrolled 157 patients with PAOD attended at University Hospital of Londrina, and unrelated 113 healthy individuals from Southern Brazil. The clinical severity of the PAOD patients was assessed by Fontaine classification and anatomoradiological categories by Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC). The MTHFR 677C > T was genotyped using real-time polymerase chain reaction. The PAOD patients showed higher Hcy than controls but the Hcy did not differ according to Fontaine and TASC categories. Patients carrying the TT genotype (recessive model) or CT + TT (dominant model) presented higher levels of Hcy than those carrying other genotypes. In conclusion, the T allele of MTHFR 677C > T variant was associated with hyperhomocysteinemia in PAOD patients, but not in controls. Moreover, this variant was not associated with the clinical stage and the anatomoradiological categories of PAOD. Our data suggested a possible interaction between MTHFR 677C > T variant and the presence of other genetic, epigenetic and environment factors associated with PAOD on modulation the metabolism of Hcy.