Regional mapping of the HLA on the short arm of chromosome 6.

A detailed gene marker study was performed on a partial 6p trisomic child resulting from a balanced maternal translocation t (2;6) (p 2505; p2105). HLA typing and mixed lymphocyte reaction showed that the breakpoint on chromosome 6 was located within the HLA gene cluster, allowing an accurate location of the D determinants. Localization of the P blood group locus within the region 6 p 2105 to 6 p ter was excluded.