The genetic polymorphism of properdin factor B(BF) was studied in different populations. The rarer alleles, BF*F1 and BF*S1, occurred in Caucasians, were less frequent in North American blacks, and were not demonstrated in any of there Oriented populations studied. Two further alleles of BF, termed BF*FM and BF*SM, were found to exist in these populations. The BF*FM allele, which was found only in Caucasian, codes for a functionally inactive factor-B product, whereas the BF*SM allele (found in a single Chinese individual), like other alleles of BF, codes for a functionally active product. HLA haplotype analyses in individuals carrying the rarer alleles of BF revealed not only a strong association between B*F1 and HLA-B18 and BF*S1 and HLA-Bw50 but an even stronger association between these BF alleles and alleles of the two C4 loci. BF*F1 occurred most frequently on a C4A*3,B*Q0 haplotype, ubreas the BF*S1 allele was usually found on a C4a*2,B*1/B*Q0 haplotype. HLA haploypes carrying the BF*FM and BF*SM alleles all carried the more common C*4A3,B*1 haplotype.
ASJC Scopus subject areas
- Immunology and Allergy