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 Bf*S allele were observed. They were provisionally named Bf*Sb1 and Bf*Sb2(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 Bf*Sb alleles was calculated to be 0.0067.