POPULATION GENETIC-STUDIES OF HLA-G - ALLELE FREQUENCIES AND LINKAGE DISEQUILIBRIUM WITH HLA-A

HLA-G is a class I gene that is expressed in the extravillous cytotrop hoblast. Although the function of this gene is still unknown, its expr ession at the maternal-fetal interface suggests that HLA-G may play a key role in the induction of tolerance during pregnancy. Preliminary t o our studies of the effects of HLA-G polymorphisms on pregnancy outco me, we have defined HLA-G alleles in the Hutterites. We report here th e presence of nine HLA-G alleles that differ with respect to nucleotid e sequences, including four groups of alleles that differ with respect to amino acid sequences, and striking linkage disequilibrium between HLA-G and HLA-A alleles. The levels and sites of polymorphism in HLA-G suggest that this gene had a unique evolutionary history and may perf orm nonclassical functions at the maternal-fetal interface. Copyright (C) 1996 Elsevier Science Ireland Ltd.