Influence of Amerindian mitochondrial DNA haplogroups on thrombosis susceptibility and frequency of four genetic prothrombotic variants in Southern Chilean subjects.

BACKGROUND: Recent evidence suggests that the ethnic background may determine the susceptibility to cardiovascular diseases. Considering the genetic composition of Chilean population, the aim of the present study was to evaluate the possible association between Amerindian mitochondrial DNA (mtDNA) haplogroups and venous thrombosis susceptibility and the influence on frequency of factor V 1691G>A, prothrombin 20210G>A, methylenetetrahydrofolate reductase (MTHFR) 677C>T and beta-fibrinogen -148C>T polymorphisms in Southern Chilean population.

METHODS: A total of 172 individuals, 60 patients with diagnosis of deep venous thrombosis (DVT) confirmed by Doppler ultrasonography and 112 controls were included in this study. The single nucleotide polymorphisms (SNP) and the Amerindian mtDNA haplogroups were detected by PCR and PCR-RFLP techniques, respectively.

RESULTS: The presence of mtDNA haplogroups did not modify the thrombosis susceptibility. Of 4 SNPs genotyped, only the MTHFR 677C>T variant was more frequent in DVT patients when compared to controls (OR 3.46; 95%CI, 1.50-8.00). A lower frequency of 1691G>A (factor V) and a total absence of prothrombin 20210G>A variants were observed in subjects with Amerindian background.

CONCLUSIONS: The presence of Amerindian haplogroups did not modify the susceptibility to DVT in the studied subjects. Only MTHFR 677C>T polymorphism was associated to venous thrombosis in Chilean subjects. The lower frequency of factor V 1691G>A and the absence of prothrombin 20210G>A polymorphism confirm the poor utility of the molecular detection of these variants in the thrombophilia study in populations with Amerindian background.