HLA-C TYPING OF 11 PAPUA-NEW-GUINEANS - IDENTIFICATION OF AN HLA-CW4 CW2 HYBRID ALLELE/

HLA-C polymorphism of 11 individuals from Papua New Guinea was studied by serology and DNA typing (SSP ARMS-PCR). To resolve certain discrep ancies HLA-C alleles were cloned and sequenced. Five alleles were iden tified by sequencing, four of which; Cw0304, Cw*0401, Cw*12022 and Cw 1502 have been identified previously in other populations. The fifth allele, which was found in four individuals is a novel HLA-C allele. T he new allele, called HLA-Cw0403 is most similar to HLA-Cw*0401, diff ering by 10 nucleotides, 9 of which are located in the region from nuc leotide 98 to 218. This region of Cw0403 is identical to both HLA-Cw* 0201 and Cw02022. The 9 nucleotide differences between Cw*0401 and Cw 0403 result in 6 amino acid differences in the alpha 1 domain. These amino acids in Cw0403 may contribute to the serological typing of som e, but not all Cw0403 expressing cells. The Final difference between Cw0401 and Cw*0403 is a coding substitution at nucleotide 979 in exon 5. The guanine found in Cw0403 is identical to all HLA-C alleles exc ept HLA-Cw0401, which has an adenine. The Cw*0403 allele was most lik ely formed by a gene conversion event between Cw02 and Cw*04, involvi ng a minimum of 121 to a maximum of 215 nucleotides.