A Haplotype Study of HLA Complex with Special Reference to the HLA‐DR Series and to Bf. C2 and Glyoxalase I Polymorphisms

Abstract

French families (53) were typed for alleles at 7 loci of the HLA complex (HLA-A, -B, -C, -DR, -Bf, -C2 and -GLO [glyoxalase 1]) and 212 haplotypes were demonstrated. Recombinations (11) were observed (2 A/B, 2 A/C, 2 B/Bf, 1 Bf/D and 4 D/GLO). The linkage disequilibrium was calculated not only between 2 alleles (.DELTA.) but between 3, 4...7 alleles (D). In order to compare the intensity of D value in the various haplotypes, the influence of the differences in gene frequencies was eliminated by the introduction of the standardized Ds (Ds = D/D max). The number of haplotypes in disequilibrium is relatively limited since most of the significant Ds involved about 17 haplotypes. For some haplotypes, the disequilibrium covered the whole distance from A to GLO but the strongest disequilibrium concerns the C to Bf or C to DR segment. Three hypotheses (isolation, admixture of population and selection) concerning the formation and maintenance of the disequilibria are discussed.