Bf Types of HLA Haplotyped Individuals in an Isolated Newfoundland Population

Abstract

Individuals [514] from an isolated Newfoundland, Canada population were typed and haplotyped for HLA and Factor B (Bf locus). The Bf gene frequencies were: S0.704, F0.226, F1 0.052 and S1 0.018. Tracing the haplotypes backwards on the various pedigrees showed that 202 HLA/Bf haplotypes were introduced into the study population. Some HLA alleles always appeared in association with particular Bf alleles and vice versa. Bf S1 entered the population 4 times, always with HLA-A9, B12. Bf F1 entered 3 times, always with HLA-B18. There were 17 entries of HLA-A1, B8 that gave rise to the 78 such haplotypes that were now present in the population; all were Bf S. There were 68 family units informative for Bf. They accounted for 240 children and 304 informative meioses. There were 3 recombinants in the HLA region but none occurred between the HLA-B and Bf loci.