Using a powerful gene-mapping technique, researchers report homing in on the location of two new genes that underlie type I diabetes. People with this form of diabetes generally require daily injections of the hormone insulin in order to survive.
Rather than hunting laboriously for a single gene associated with diabetes, a British research team headed by John A. Todd of the University of Oxford in England relied on a method that allows simultaneous analysis of all 46 human chromosomes. At a genetics meeting in Bar Harbor, Maine, in July, Todd reported that their genomewide sweep had revealed 18 different chromosome regions linked to type I diabetes (SN: 8/6/94, p.85). He also said the group had confirmed the importance of the IDDM1 gene in this form of diabetes, an autoimmune disorder.
In the Sept. 8 NATURE, Todd's team further refines the emerging picture of this complex disorder, which is caused by the interaction of many genes and environmental factors. In a study of families with at least one afflicted member, the researchers found a region on the long arm of chromosome 11 and another on the long arm of chromosome 6 that are associated with type I diabetes. The scientists believe that the DNA sections of those chromosomes house two new genes for type I diabetes. …