Laboratory testing of hereditary thrombophilia: previous data in the face of verification

Mutations in hemocoagulation factors genes are nowadays routinely examined parameters, important in hereditary trombophilia determination. We have complexly evaluated laboratory data from the 211 unselected patients with venous thrombosis, and compared with the former studies in the same Slovakian population.

The Factor V Leiden mutation (FVL) was found in 43 of 211 patients (20.38%), with the mutant allele frequency=10.2%, while the prothrombine G20210A mutation was revealed in 11/205 individuals (5.37%), with the mutant PT 20210A allele frequency=2.68%. In both mutations, all carriers of mutant allele were heterozygotes. In 81 individuals was examined the PCAT-NR with the ProC Global assay. Of them, 24 was heterozygotes for FVL mutation with considerably lower PCAT-NR levels (median=0.67; range: 0.53-0.83) compared with homozygotes without FVL mutation (n=57; median=0.84; range: 0.54-1.67; p<0.001). The sensitivity of the assay was 0.88 (95% CI: 0.68-0.97) and the specifity =0.67 (95% CI: 0.53-0.79).

Our examination revealed considerably lower frequency of the FVL mutation in the target population, by contrast to the neighbouring Caucasian populations. As for the PT 20210 mutation, the differences are milder. Even though the PCAT-NR was validly sensitive (sensitivity=0.88, 95% CI: 0.68-0.97) to the FVL mutation, only DNA-testing is the definitive assay for FVL-carriership (Ref. 19). Full Text (Free, PDF) www.bmj.sk.