Prevalence of Factor V Leiden, Prothrombin G20210A, and MTHFR C677T Mutations in 200 Healthy Jordanians

Extract

Thrombophilia is now considered a multi-causal condition, with interplay of acquired genetic risk factors. In order to estimate the frequency of the factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations in the Jordanian population, we screened 200 healthy Jordanian individuals. 40% were females. Mean age was 32.1 years for males and 30.0 years for female participants. A PCR method detected 15.0% factor V Leiden (87% heterozygous, 13% homozygous), 2% prothrombin G20210A (100% heterozygous), and 24% MTHFR C677T (67% heterozygous, 33% homozygous).

We conclude that the prevalence of factor V Leiden and MTHFR C677T is elevated in this population of Jordanians. However the incidence of G20210A is relatively low.

Quantification of these genetic thrombosis risk factors in various populations will contribute to a better understanding of the interaction of genetic and environmental risk factors.

Thrombosis risk factors predispose towards thrombosis but, due to the episodic nature of thrombosis, interaction with other components is required before onset of the clinical disorder. A well-established genetic predisposition to thrombosis is a single point mutation in the gene encoding coagulation factor V (G1691A) leading to factor V Leiden (FVL) which was identified as the molecular basis for the phenotype of activated protein C resistance (APC-R) in the majority of affected individuals.^1,2 This mutation is associated with a five- to ten-fold risk for heterozygotes and 80-fold risk for homozygotes.³

In 1996, Poort found that the genetic variant in the 3′ untranslated region (a G to A transition at position 20210) is associated with elevated plasma…

ABBREVIATIONS: APC-R = activated protein C resistance; AS-PCR = allele specific polymerase chain reaction; FVL = factor V Leiden; M = mutant; MTHFR = methylenetetrahydrofolate reductase; PCR = polymerase chain reaction; W = wild.