Original Paper - Comparison of the incidence of MTHFR C677T homozygosity and hyperhomocysteinemia in patients with and without thromboembolism

G. Sottilotta, G.M. Nicolò, M. Cordaro, F. Luise, V. Oriana, A. Piromalli

Background: The association between methylene tetrahydrofolate reductase (MTHFR) polymorphisms, high homocysteine (HCY) and the risk of thrombosis is still ambiguous. Aims: The aim of our study was to analyze retrospectively the incidence of homozygosity for MTHFR, HCY levels and thrombosis. Materials and methods: We retrospectively analyzed the clinical data of 407 subjects followed up by our centre: 270 with homozygosis for MTHFR C677T mutations and normal or elevated HCY levels compared to 137 subjects without thrombophilia. Results: In both groups with MTHFR C677T homozygosity, the incidence of thrombosis was lower than in the group of subjects without MTHFR mutation and normal HCY levels, but this difference was statistically significant only when we compared subjects without thrombophilia to those with homozygosis for MTHFR C677T and normal HCY. Conclusions: Differently from other studies, we did not observe a correlation between thrombotic risk and MTHFR C677T homozygosity. We confirmed the importance of homocysteine in the etiopathogenesis of thrombosis, although it is probably still not clear which level of hyperhomocysteine should be considered as a real risk factor for thrombosis...

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