SUBALLELES OF THE ABO BLOOD-GROUP SYSTEM IN A JAPANESE POPULATION

The nucleotides (nt) at positions 467 and 646 of the ABO blood group s ystem were analyzed in a Japanese population by means of the polymeras e chain reaction (PCR) and restriction fragment length polymorphism (R FLP) methods. Two types at nt467, tentatively designated 'Pro' and 'Le u', were found in the common A (=A(1)) alleles, and two types at nt646 named 'T' and 'A' were found in O alleles. The types at nt467 of B an d O alleles were Pro and those at nt646 of A and B alleles were T. The refore, A alleles were divided into A(Leu) and A(Pro) suballeles and O alleles were divided into O(T) and O(A). The allele frequencies in th e present survey were calculated as ABOA(Pro) = 0.0712, ABO*A(Leu) = 0.2163, ABOB = 0.1779, ABO*O(T) = 0.2731 and ABO*O(A) = 0.2615. No O- 2 (or O-(3)) allele was observed in the population samples. At least f ive alleles with polymorphic frequencies and 15 genotypes are present in the Japanese sample.