Hemopexin: a unique genetic polymorphism in populations of African ancestry.

Using isoelectric focusing and immunoblotting techniques, we have screened 937 plasma or serum samples from Nigerian blacks (N = 380), Papua New Guineans (N = 110), Aleuts (N = 62), Mayans (N = 139), Dogrib Indians (N = 45), and Eskimos from Kodiak and St. Lawrence islands (N = 201) for the hemopexin (HPX) polymorphism. We compared these data with our previously published data for US whites (N = 267) and US blacks (N = 194). Except for Nigerian blacks and US blacks, HPX was found to be monomorphic for the common HPX*1 allele in all populations tested. In addition to the commonly occurring HPX*1 allele, two other less common alleles, HPX*2 and HPX*3, were observed with respective frequencies of 1.8% and 4.6% in US blacks and 1.7% and 9.0% in Nigerian blacks. These data strongly suggest that the HPX*2 and HPX*3 alleles are unique alleles restricted to the black gene pool and are of potential significance in microevolutionary studies and in defining African admixture in hybrid populations. In addition to their importance in anthropogenetic studies, these unique HPX mutations also have potential biological significance in hemolytic disorders.