THE HIGH PREVALENCE OF THERMOLABILE 5-10-METHYLENETETRAHYDROFOLATE REDUCTASE (MTHFR) IN ITALIANS IS NOT ASSOCIATED TO AN INCREASED RISK FORCORONARY-ARTERY DISEASE (CAD)

Mild hyperhomocysteinemia was found to be related to venous thrombosis , cerebrovascular and coronary artery disease (CAD). Some recent studi es suggested that a mutation in the gene encoding for 5-10 methylenete trahydrofolate reductase (MTHFR), due to a transition C --> T at nucle otide 677, is a genetic risk factor for vascular disease. However, sev eral further studies could not confirm this association. We investigat ed 84 patients with CAD who underwent percutaneous transluminal corona ry angioplasty (PTCA) and 106 healthy subjects. The prevalence of the mutated homozygous genotype was much higher than in other Italian popu lations, Europeans or other major human groups, but no excess of the V al/Val homozygotes was found in patients (28.5%) with respect to healt hy subjects (30.2%). Mutated homozygous MTHFR genotype (+/+) was not f ound to be related to the clinical manifestations of CAD, to the preva lence of the common risk factors and to the rate of restenosis. In con clusion, thermolabile MTHFR does not appear to be associated ''per se' ' with the risk for CAD or for restenosis after PTCA. The high frequen cy of the +/+ genotype in our Italian population (from Tuscany) confir ms a wide macroheterogeneity and suggests a microheterogeneity in the genotype frequencies of the different ethnic populations.