Two new Bf S subtypes revealed by isoelectric focusing and immunofixation.

The genetic types of the properdin factor B were analyzed by isoelectric focusing on polyacrylamide gels and subsequent immunofixation. Sera from 516 unrelated, healthy individuals from Southern Germany were examined. Two new subtypes of the BfS allele were observed. They were provisionally named BfSb1 and BfSb2(b = basic), since the position of their bands is located slightly towards the cathode. Whereas Bf Sb2 has, thus far, been found only in a single individual, Bf Sb1 was found in five unrelated persons and in a mother and her child indicating a simple codominant mode of inheritance. The combined frequency of the BfSb alleles was calculated to be 0.0067.