Distribution of ABO blood group genotype in Nara prefecture and its familial diagnosis.

We have recently reported the DNA analysis of ABO blood group genotypes by using polymerase chain reaction followed by restriction enzyme digestion according to the method of Yamamoto et al (Nature 345: 299-233, 1990). In this paper, we describe the distribution on ABO genotype in Nara prefecture. Genomic DNAs were obtained from 253 healthy volunteers which include 100-phenotype A, 100-phenotype B, 32-phenotype O, and 21-phenotype AB. The theoretical distribution of genotype AA was 20.8%, and that of BB was 14.3% based on the calculation of Hardy-Weinberg equation in Nara prefecture. DNA anlaysis revealed that the value of genotype AA was 17%, and that of BB 14%. This result was in good accord with the theoretical values. Then, we investigated the ABO genotype status in 5 Japanese families including 25 familial members, of which parents showed the following phenotypes; B×B, O×AB, AB×AB, B×A, and AB×A. No conflict genotype was observed in these family members, proving the accuracy of this method.