A REGION OF PRIMER BINDING VARIATION AT THE D6S265 LOCUS ASSOCIATED WITH HLA-A25 AND HLA-A26 ANTIGENS

D6S265 is a polymorphic dinucleotide repeat, mapped within 70 kb centr omeric of HLA-A on chromosome 6p21.3. While genotyping families for ge netic linkage analysis, allele non-amplification resulting in apparent non-Mendelian inheritance was observed at the D6S265 locus in 15 indi viduals, on chromosomes carrying the HLA-A25 and HLA-A26 antigens. The D6S265 locus was sequenced in a variant individual homozygous for all ele non-amplification, and in a non-HLA-A25/-A26 individual, homozygou s for D6S265 allele 1. Five base changes were identified in the revers e primer binding region of the variant individual, effectively prevent ing annealing of the 3' primer to the template.