HLA AND MATE CHOICE IN HUMANS

Evidence from studies in rodents suggests that mate selection is influ enced by major-histocompatibility-complex haplotypes, with preferences for dissimilar partners. This study was initiated to determine whethe r avoidance of a mate with the same HLA haplotype as one's own might b e occurring in the Hutterites, a North American reproductive isolate o f European ancestry, notable for their large sibships, communal lifest yle, and limited number of five-locus HLA haplotypes (HLA-A, -B, -C, - DR, and -DQ). HLA haplotypes were known for 411 Hutterite couples. The number of couples expected to match for a haplotype was calculated in two ways: first, from population genotype frequencies, with account b eing taken of the nonrandom mating pattern with respect to colony line ages, and, second, from computer simulations using conservative founde r assumptions and the exact genealogy of the 411 couples. We observed fewer matches for HLA haplotypes between spouses than expected (first method, P =.005; second method, P =.020-.067). Among couples who did m atch for a haplotype, the matched haplotype was inherited from the mot her in 29 cases and from the father in 50 cases (P =.018). These resul ts are consistent with the conclusion that Hutterite mate choice is in fluenced by HLA haplotypes, with an avoidance of spouses with haplotyp es that are the same as one's own.