High incidence of two methylenetetrahydrofolate reductase mutations (C677T and A1298C) in Hispanics.

Mutations in the 5,10-methylenetetrahydrofolate reductase (MTHFR) and coagulation factors II and V genes have been found at high frequencies in European and American Caucasian populations and are associated with increased risk for thrombophilia, premature coronary artery disease, and a variety of adverse pregnancy outcomes. Hispanic populations in the United States exhibit high levels of some of these conditions, so we initiated a population-based study to determine the frequency of these mutations (MTHFR C677T and A1298C, Factor II G20210A and Factor V G1691A) in this group. We find comparable frequencies of the Factors II and V mutations, but a high incidence of the two MTHFR mutations in a diverse sample of American Hispanics compared to those reported in Caucasians. Prospective studies of Hispanic women with these mutations and pregnancy outcomes will establish if there is a causal relationship.