Human insulin-related DNA sequences map to chromosomes 2 and 11

The insulin-related hormone family consists of four known peptides: insulin, the insulin-like growth factors I and II, and relaxin. To investigate the hypothesis that the family contains additional members, we have isolated a series of human genomic clones using the insulin gene as a hybridization probe. Two of these single copy DNA sequences, hIr 1 and hIr 2, have been localized to chromosome 2 and 11p11→q13, respectively, by Southern blot analysis of mouse-human somatic cell hybrids, a result consistent with other evidence supporting the dispersal of the insulin gene family throughout the genome. Although a biological function for these DNA sequences has not yet been established, hIr1 and hIr2 are potentially useful as molecular probes for mapping, by analysis of restriction fragment length polymorphisms (RFLP), genetic disorders linked to chromosomes 2 or 11.