Genetic polymorphism of factor B (Bf) in Okayama Prefecture, Japan.

The genetic polymorphism of factor B (Bf) was investigated in Okayama Prefecture, Japan. Cellogel immunofixation electrophoresis was employed according to Martin and Ziegler (1981) with minor modifications. In 316 non-blood related Japanese, the Bf was: Bf S, 70.6%; Bf FS, 27.8%; and Bf F, 1.6%. No rare variants were observed. The gene frequencies of Bfs and BfF were 0.845 and 0.155, respectively. The gene frequencies in Okayama Prefecture were quite similar to those in other districts of Japan. Considering the phenotype distribution in Japan, the Bf system might be a useful marker for personal identification and in disputed paternity cases.