Polymorphism of properdin factor B in Japanese. Description of a rare variant and data of association with HLA and C2.

Polymorphism of the properdin factor B (BF) was investigated using an agarose gel immunofixation electrophoresis in 487 unrelated healthy adult Japanese who were already typed for HLA-A, -B, -C and C2. Besides the previously reported phenotypes in Japanese (S, FS, and F), a rare heterozygous phenotype (tentatively maned FTS) was observed once. The estimated allele frequencies for BS*S, BF*F, and FB*FT (F Tokyo) were 0.801, 0.198, and 0,001 respectively. The relative electrophoretic mobility of the variant band of type FTS was measured by Dr. G Mauff to be F 0.75. The conversion fragment Bb of the type showed a double-banded pattern. BF hemolytic activity of the FTS individual was at the same level as other phenotypes. Statistical tests for the phenotypic data of BF with HLA-A, -B, -C, and C2 indicated the presence of the following significant associations in Japanese: Aw33-BF*F, A11-BF*S, Aw24-BF*S, B15-BF*F, B17-BF*F, Bw44-BF*F, B7-BF*S, Bw52;-BF*S, BW54-BF*S, BW59-BF*S, Cw3-BF*F, C2*AT-BF*F, and C2*A'-BF*F.