The discovery of many associations between HLA and human diseases has emphasized the biologic importance of the main histocompatibility system in man. The recent findings from specific immune response genes (Ir locus) mapping within the H2 region of the mouse have led to systematic study of the similar D locus mapping within the HLA region in man. In this study the frequency of a number of HLA-D antigens has been determined in normal individuals and in patients with four diseases selected in view of their genetic background: juvenile diabetes, multiple sclerosis, grass pollinosis and acute leukemia. In each a significant association has been found with a specific HLA-D antigen: DW3 in juvenile diabetes and grass pollinosis, DW2 in multiple sclerosis, and DW7 in acute lymphoblastic leukemia.
B-Lymphocytes Chromosome Mapping