HLA-CW ALLELES ASSOCIATED WITH HLA EXTENDED HAPLOTYPES AND C2 DEFICIENCY

There are four NMC-linked complement genes, BE C2, C4A and C4B, that a re inherited as single DNA units, known as complotypes. Extended haplo types were initially defined by studying the distribution of complotyp es in relation to HLA-B and HLA-DR loci in Caucasian families. In orde r to analyze the distribution of HLA-Cw alleles in relation to extende d haplotypes, we studied a large panel of MHC homozygous and hetero zy gous cell lines representing previously described Caucasian derived ex tended haplotypes and 14 patients with complete C2 deficiency. HLA all eles were assigned using sequence-specific oligonucleotide probe hybri dization (SSOP). Family analysis served to assign haplotypes for heter ozygous samples. We found distinctive HLA-Cw alleles for each independ ent extended haplotype. Their association in each instance was statist ically significant. All patients with C2 deficiency carrying the haplo type [HLA-B18, S042, DR2] were associated with HLA-Cw1203. These cons erved allelic combinations may become an important tool for the study of human evolution and may contribute to the expeditious selection of prospective donors in clinical transplantation.