PREVALENCE OF THE FACTOR-V-LEIDEN MUTATION IN 4 DISTINCT AMERICAN ETHNIC POPULATIONS

Resistance to activated protein C (APC) is the most common risk factor for venous thromboembolism, a major cause of morbidity and mortality with an incidence of about 1/1,000 per year, The Arg 506 to Gln mutati on in exon 10 of the coagulation factor V gene (factor V-Leiden) has b een found to be responsible for over 90% of the APC resistance cases a nd is an autosomal dominant trait, initial studies have suggested that this mutation is restricted to individuals of European Caucasian extr action with an average allele frequency in European and American Cauca sians of 4.4%, making it one of the most common monogenic disorders in the Caucasian population, A limited number of other ethnic population s have been tested and the mutation has been found only rarely. In our multiethnic survey of 602 individuals, Hispanic-Americans had the hig hest observed frequency of the factor V-Leiden mutant allele, 1.65%, w hile African-Americans had a somewhat lower frequency, 0.87%. No facto r V-Leiden mutations were found in 191 Asian-Americans or 54 Native-Am ericans tested, These results indicate that the factor V-Leiden mutati on segregates in populations with significant Caucasian admixture and is rare in genetically distant non-European groups, This ethnic strati fication may be important in developing cost-effective selective scree ning programs to identify individuals at risk for thromboembolism and offer prophylactic therapy, (C) 1997 Wiley-Liss, Inc.