Studies of HLA, fertility and mate choice in a human isolate.

The role of human leukocyte antigen (HLA) genes in pregnancy and in human mate choice has been investigated in the Hutterites, an inbred population of European origins. High-resolution HLA haplotypes were defined by alleles at 16 loci in >1000 Hutterites. Prospective studies of pregnancy outcome previously demonstrated increased fetal loss rates among Hutterite couples matching for HLA-B antigens (P = 0.033) or for the entire 16-locus haplotype (P = 0.002). Among living children of couples matching for HLA-B or for the haplotype, there was a non-significant deficit of children who were heterozygous and compatible with the mother; the number of living children who were compatible and homozygous or incompatible and heterozygous was not different than expectations (HLA-B, P = 0.095; haplotype, P = 0.376). Mate choice among 411 couples was non-random with respect to the HLA haplotype, assessed by a variety of methods (P = 0.020 to <0.001). These combined data indicate a role for HLA region genes in both pregnancy outcome and mate choice, and suggest that selection acting on these genes occurs pre-conceptually as well as during pregnancy. This review outlines previously published studies on HLA, fertility and mate choice in the Hutterites.