Genetic polymorphism of red cell membrane band 3 in Japanese Brazilians.

Limited proteolysis of intact red cells has been shown to yield peptides of 60 kDa and, in some individuals, 63 kDa, from the band-3 membrane protein. In a random population sample of 117 Brazilians of Japanese origin, the allele frequencies of the band-3 variants were p60 = 0.889 +/- 0.0205 and p63 = 0.111 +/- 0.0205. The phenotype frequencies fit the Hardy-Weinberg equilibrium for the hypothesis of three phenotypes controlled by two codominant alleles of a single autosomal locus. The frequencies of the alleles in this population of Japanese ancestry are highly different from those of Brazilian Caucasoid blood donors but rather similar to those of Brazilian Negroid donors.