Two common genetic thrombotic risk factors: factor V Leiden and prothrombin G20210A in adult Turkish patients with thrombosis.

The prevalence of genetic risk factors for thrombosis varies greatly in different parts of the world, both in patients with thrombosis and in the general population. Factor V Leiden (FVL) and prothrombin G20210A (PT G20210A) mutations are the most common genetic defects leading to thrombosis. We have previously reported that those two thrombotic risk alleles are frequently found in Turkish children with thrombosis. The aim of the present study was to investigate the frequency of FVL and PT G20210A and their clinical manifestations in adult Turkish patients with thrombosis. Between January 1997 and February 2000, 146 patients with documented thrombosis were investigated in our center for the presence of the FVL and PT G20210A mutations. Forty-five of 146 patients with thrombosis (30.8%) were detected to have FVL mutation. Among those cases with the FVL mutation, seven (4.8%) had homozygote and 38 (26%) had heterozygote mutation. The PT G20210A mutation was detected in 10 of the 146 patients with thrombosis (6.8%). Another six cases (4.1%) had both FVL and PT G20210A mutations. The overall frequency of these two common risk alleles in our adult population with thrombosis was 41.6%. Our findings reveal that FVL and PT G20210A mutations are significant genetic risk factors contributing to the pathophysiology of thrombosis in the Turkish population. Copyright 2001 Wiley-Liss, Inc.