Factor VII polymorphisms in populations with different risks of cardiovascular disease

Increased plasma factor VII coagulant activity (FVII:C) has been associated with the risk of ischemic heart disease (IHD). Differences in plasma FVII:C among individuals are associated with three common polymorphisms in the FVII gene. Therefore, we investigated FVII polymorphisms in four populations that differ in their risk of developing cardiovascular disease, namely, Europeans, Greenland Inuit, Gujarati Indians, and Afro- caribbeans. We studied (1) the promoter polymorphism, which is the result of a decanucleotide insertion in the FVII promoter at position -323 from the start of translation; (2) the hypervariable region 4 polymorphism (HVR4), which is the result of a variable number of tandem repeats in intron 7; and (3) the RQ353 polymorphism, a guanine-to-adenine substitution in the position of the codon for amino acid 353 resulting in an amino acid replacement of arginine (R) by glutamine (Q) in the FVII protein. The frequencies of these three polymorphisms and their linkage disequilibrium were different in the four populations studied. The frequencies of the alleles associated with higher plasma FVII:C were lower in the Europeans than in the Inuit, a population with a lower incidence of IHD. There was an association between both the promoter polymorphism and the RQ353 polymorphism and the plasma FVII:C in the Europeans, the Inuit, and the Gujarati Indians, and an association only between the RQ353 polymorphism and plasma FVII:C in the Afro-caribbeans. Only in the Inuit was the HVR4 polymorphism associated with plasma FVII:C. In multiple regression analysis, the additional information provided by the promoter polymorphism when the other polymorphisms were already included in the model was the most pronounced, suggesting that the promoter polymorphism may be the functional mutation having the greatest effect on determining plasma FVII:C.