HLA-A null haplotype by HLA-A deletion

Abstract

An HLA-A null haplotype was observed in a Japanese family by serological typing. The individual with HLAA31/blank were typed as HLA-A*3101 homozygote by both PCR-SSP and PCR-SBT methods. The PCR amplification of genomic DNA using an HLA-A locus-specific primer set designed with 3'- and 5'-untranslated regions produced only an approximately 3 kb fragment, which was expected from full length HLA-A. An approximately 10 kb fragment shorter than that of wild-type HLA-A was detected by pulse field electrophoresis analysis of Mlu I-digested DNA fragment. The nearest gene of HLA-A, HCGIX, was found to be 30 kb away from HLA-A on the side of the centromere. Therefore, the HLA-A null haplotype seemed to lack 10 kb including only HLA-A.