Prevalence of factor V G1691A (Leiden) and prothrombin G20210A polymorphisms among apparently healthy Jordanians.

: Factor V Leiden and prothrombin G20210A are related genetic risk factors for venous thromboembolism (VTE). Analysis for both mutations is increasingly being performed on patients exhibiting hypercoagulability. The objective of this study was to determine the prevalence of factor V Leiden (FVL), prothrombin-G20210A (PT-G20210A) polymorphisms and their coexistence among apparently healthy Jordanians. One thousand apparently healthy individuals from representative regions of Jordan with no previous history of VTE participated in this study. The mean age of participants was 28.5+/-6.4 years (age range 18-45 years). Two hundred and eighteen subjects were APC resistant with an APC-R mean of 85.52+/-15.35 seconds; the non-resistant subjects had an APC-R mean of 159.90+/-26.96 seconds. A multiplex polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the simultaneous detection of FVL and prothrombin G20210A was used to analyze the 218 DNA samples that were APC-R resistant. Both mutations generate HindIII RFLPs and the prothrombin amplicon contains an invariant HindIII recognition sites. The multiplex PCR-RFLP of Factor V for those 218-samples was: 41 wild-type, 169 heterozygous mutant, and eight homozygous mutant individuals. For prothrombin G20210A, the multiplex PCR-RFLP identified 215 wild-type and three heterozygous mutant individuals. Factor V positive individuals (n=50) had a mean F-V activity of 78.04%+/-25.81. F-V activity among wild type (n=41), F-V Leiden heterozygous (n=169) and F-V Leiden homozygous (n=8) were 92.93%+/-16.17, 87.02%+/-15.21 and 96.14%+/-12.32, respectively. Factor II positive subjects (n=47) had a mean factor II activity of 127.96%+/-21.37. F-II activity among carriers (heterozygous, n=3) and non-carriers (normal, n=215) of PT-G20210A mutation were 107.67%+/-9.29 and 105.00%+/-17.79, respectively. The prevalence of FVL was 21.8% and there is a little likelihood of the co-inheritance of the FVL and PT-G20210A among healthy young adults, since only few cases were found to be carriers for the two alleles.