Prevalence of the activated protein C resistance in indigenous and Black populations of the western Venezuela

: The Activated Protein C Resistance (APCR) is the common phenotype of Factor V Leiden (arg506gln), which is considered as a thrombotic risk factor. The aim of this study was to determine the prevalence of APCR and its association with Factor V Leiden in indian and black populations from Zulia State in western Venezuela. Blood samples were taken from 80 Yukpa indians from Sierra de Perija and 91 black individuals from the southeast of Lago de Maracaibo. APCR was determined by the Dahlback's method with the modifications of Jorquera et al. and Trossaert et al. The results were expressed as n-APC-SR (positive value < or = 0.75). Factor V Leiden genotype was identified by PCR and restriction analysis standard methods at the Institute of Human Genetics (Greifswald, Germany). No significative difference was found between n-APC-SR from indians (mean +/- SEM 1.13 +/- 0.02, CI 95% = 1.07-1.19) and black people (1.07 +/- 0.02, CI 95% = 1.03-1.12). APCR prevalence from indians was 1.25% (1 out of 80) who was heterozygote case for F V Leiden and 4.4% (4 out of 91) from blacks (one case was heterozygous for F V Leiden). No thrombotic event personal or familial was demonstrate. Our data represent the first report related to the association between APCR and F V Leiden in venezuelan indian and black individuals. APCR without the Factor V Leiden expression suggest a different type of mutation in the Factor V molecule. In spite of high endogamy in the indian group, we can not discard the role of foreign genes in both populations. The determination of the prevalence of this phenotype and its molecular marker in various ethnic groups is important for the interpretation of their role as risk factors for thrombotic disease.