MARKERS ON DISTAL CHROMOSOME 2Q LINKED TO INSULIN-DEPENDENT DIABETES-MELLITUS

Insulin-dependent diabetes mellitus (IDDM) is a multigenic autoimmune disease. An IDDM susceptibility gene was mapped to chromosome 2q34. Th is gene may act early in diabetogenesis, because ''preclinical'' indiv iduals also showed linkage, Human leukocyte antigen (HLA)-disparate, b ut not HLA-identical, sibs showed linkage, which was even stronger in families with affected females. The genes encoding insulin-like growth factor-binding proteins 2 and 5 were mapped to a 4-megabase pair inte rval near this locus, These results indicate the existence of a gene t hat acts at an early stage in IDDM development, screening for which ma y identify a specific subset of at-risk individuals.