Prevalence of factor V Leiden in African-Americans.

Factor V Leiden (FVL) refers to a mutation on the clotting factor, Factor V. Protein C is a factor involved in the fibrinolytic pathway. Activated protein C (APC) normally degrades activated Factor V. The presence of the Leiden mutation on Factor V makes this protein resistant to degradation by APC, leading to a hypercoagulable state. Previous studies reported a prevalence of FVL in various populations between 0-6% and absent in Africans. We studied two factor V alleles from one hundred random blood samples submitted for CBC. DNA was extracted, PCR was performed for wild-type allele and Leiden mutation with GH internal control for both reactions, and agarose gel electrophoresis was performed. Of 100 samples, five were heterozygous for FVL, which is in accord with other reports. Interestingly, four of 70 samples (5.8%) from African-Americans were positive for the mutation. The study indicates an apparent prevalence of 5% in the Newark, New Jersey population, including African-Americans.