Cw * 1701 defines a divergent African HLA-C allelic lineage

Wells, R.S., Seielstad, M.T., Bunce, M., Tyan, D.B., Bekele, E. and Parham, P. (1997) Cw * 1701 defines a divergent African HLA-C allelic lineage. Immunogenetics, 46 (3). pp. 173-180.

Abstract

The complete sequence of a new HLA-C allele, Cw * 1701, was determined from a South African Zulu individual. Unique features that distinguish Cw * 1701 from other HLA-C alleles include multiple point substitutions and an 18 nucleotide insertion in exon 5, which encodes the transmembrane domain. In a phylogenetic analysis of HLA-C sequences, Cw * 1701 forms a third, distinct allelic lineage. A comparison of the transmembrane domain of Cw * 1701 with other HLA-B and -C alleles reveals that duplications and deletions have been common in the evolution of these loci. A polymerase chain reaction based typing method was used to determine the distribution of this unusual allele in human populations. In contrast to the other two lineages of HLA-C alleles, the Cw * 17 lineage is found at high frequencies only in populations of African descent. In addition, the HLA-B/Cw * 17 haplotype diversity is higher in Africa.