The Saudi Thrombosis and Familial Thrombophilia Registry. Design, rational, and preliminary results.

To describe the Registry and report preliminary data for the prevalence of 5 prothrombotic gene mutations in the normal Saudi population.Blood from consenting healthy Saudi individuals and patients with venous thrombosis (VT) from different regions of the Kingdom was collected from November 2001 until July 2007. The extracted DNA of each sample was kept at -70 degrees C until tested for 5 known prothrombotic factors using established methods. Only patients with confirmed VT were included. Data generated through direct interview were entered into the Saudi Thrombosis and Familial Thrombophilia (S-TAFT) Register. The consent and demographic data collection forms and the S-TAFT Register were developed using the SQL web based software.Nine hundred and two DNA samples of consenting healthy Saudi individuals were tested for factor V Leiden (FVL), prothrombin (PT) 20210 G>A, 5-10 methylenetetrahydrofolate reductase (MTHFR) 677 C>T, the 4G/5G polymorphism of Plasminogen activator inhibitor type 1 (PAI-1 4G/5G), and factor V HR2 (FVHR2) haplotype. The incidence of FVL among healthy subjects was 1.3%, PT 20210 G>A 0.7%, homozygous MTHFR 677C>T 2.45%, PAI 4G/4G 10.1%, and FVHR2 26.1%.Our preliminary data from healthy Saudi individuals suggest that the incidence of the 5 prothrombotic risk factors is lower than in most other populations, except for FVHR2.