SEQUENCE OF 4 NEW HLA-CW ALLELES - A POSSIBLE ROLE OF INTERALLELIC RECOMBINATION

In order to extend our current understanding oi HLA-C polymorphism, fo ur new alleles have been cloned and sequenced: Cw1801 in a donor oi m ixed origin, Cw02024 in a Senegalese individual, Cw*1205 and Cw*1604 in European Caucasoid blood donors. HLA-Cw1801, which most likely res ults from an interallelic recombination between Cw0701 and 0401 allel es, was not associated with B8101, but with either B*4403 or B18. The Cw02024 allele differs from Cw*02022 by a silent mutation in exon 3. Both Cw1801 and Cw*02024 appear to be rather frequent in populations of African origin but have not yet been detected in Caucasoids. HLA-C w1604 differs from Cw*1601 by two nucleotides at codon 156 leading to a Gln to Trp substitution. This new Cw16 subtype was subsequently ide ntified in three additional unrelated families, all of South-European origin, and presented an unusual association with B4402 in all cases. HLA-Cw1205 is a composite allele with the alpha 1 domain of Cw*1602 and the alpha 2 domain of Cm1203, It appears to be rare, al least in European Caucasoids. Three of these four alleles map have resulted fro m gene conversion-like or interallelic recombination events.