Haplotype analysis of the linkage group HLA-A:HLA-B:Bf and its bearing on the interpretation of the linkage disequilibrium

Abstract

The analysis of 650 HLA-A:HAL-B:Bf three-factor haplotypes revealed significant associations only between alleles of the very closely linked genes HLA-A and HLA-B, and Bf, respectively. Most striking is the highly significnat association of the rare Bf variant F1 with HLA-B18 and of S1 with HLA-B13, HLA-B14, and HLA-Bw21. Only random allele distributions were observed when considering the somewhat more distant genes HLA-A and Bf or the higher order interaction at all three genes. From these findings it seems likely that the linkage disequilibrium within the MHC is not due to selective forces, but rather due to a short evolutionary period.

Properdin Factor B Polymorphism in Portugal

“…A great number of FI variants were found among the Portuguese. Our results for Bfs = 0.6535 are considerably lower than the Bfs frequencies found for northern Europe, such as those for Norway with Bfs = 0.817 [Teisberg and Olaisen, 1977], for Freiburg with Bfs = 0.814 [Bender et al, 1977] or for Cologne with Bfs = 0.808 [Maujf et al, 1975].…”

Strong Linkage Disequilibrium between HLA—Dw2 and BfS in Multiple Sclerosis and in the Normal Population

“…finding raises the possibility that all dis-HLA-D, Bf interaction on the surface of B cells and may not be a valid argument against important HLA, Bf interactions as proposed by Bender et al (1977).…”

“…Disequilibria between HLA-A and B locus antigens and Bf were sought in a large German study involving 325 normal individuals, all of whom were genotyped by family studies. HLA-D typing was not performed (Bender et al 1977). Associations were found between BfS and HLA-B8 (P < 0.01), HLA-Bw40 O .…”

“…The detection of associations at a population level of alleles of several of the closely linked loci (linkage disequilibria) of the major histocompatibility complex (MHC) and the discovery of genes responsible for the production of a number of components of the complement system have resulted in considerable interest in possible functional interactions between the products of different loci and the evolutionary significance of the region (Bodmer & Thompson 1977). In particular, gene loci controlling the production of C2, C4 and Properdin factor B (Bf) have been con- 0001-2815/79/070086--12 $02.50/0 @ 1979 firmed as residing in the HLA region (see Jersild et al 1976), and linkage disequilibria (LD) have been reported between HLA antigens and C2 deficiency (see Jersild et al 1976), a structural C2 allele (Meo et al 1976), Bf alleles (Bender et al 1977), C4 alleles ) and the absence of Chido (Middleton et al 1974) and Rodgers (Giles et al 1976) antigens, the last two now being recognised as variants of C4 (O'NeiI1 et al 1978).…”

Properdin factor B-polymorphism in the population of Hessen, Germany

“…A linkage disequilibrium between Bf and HLA-B loci (BfF/Bw5, BfS/B8, BfS0.7/Bw21, BfF1/B18) has been described previously , Olaisen et al, 1975, Bender et al, 1977 The distribution of Bf alleles appears suitable for an application of this polymorphism in selected cases of disputed paternity (Mauff et al, 1975). The present communication reports results of a population study in West Germany; they are compared with those of other authors.…”