Properdin factor B-polymorphism. An indication for the existence of a Bf O-allele

The polymorphism of the properdin factor B (Bf, C3-proactivator, GBG = glycin-rich-beta-glycoprotein) has been investigated by high voltage agarose gel immunofixation electrophoresis in 1115 unrelated persons from Southern Germany. Seven phenotypes were observed; the allele frequencies were calculated as BfS = 0.8094, BfF = 0.1790, BfSI = 0.0094, BfFI = 0.0022. A study of 94 parents with 98 children and 420 mother-child combinations showed no deviation from the assumed autosomal codominant mode of inheritance. In one additional family the findings suggested the existence of a silent allele at the Bf-locus.