Genetic Predictors of Disease
Type 1 diabetes is a chronic autoimmune condition with a complex etiology. Susceptibility to this disease has both a genetic and an environmental component; however, current knowledge about familial risk accounts for only about 10 percent of affected individuals. Current trials focus on preventing the disease in those with recognized familial risk, leaving over 90 percent of potentially affected individuals unidentified until disease onset.
Dr. Nobles work includes detailed molecular typing of multiple loci in the HLA region of chromosome 6, an area with a well-established association with susceptibility to autoimmune conditions, including type 1 diabetes. The HLA genes are the most polymorphic genes known in any mammalian system, with over 200 alleles at some loci. The pattern of disease association differs among ethnic groups. Noble hopes to clarify the patterns of inherited risk by comparing data from a large set of Caucasian, type 1 diabetes families with those from other ethnic groups, including Mexican-American, Asian, and African-American.
By examining samples from a variety of ethnic groups, Noble hopes to define a set of criteria that will serve to increase the power of predictive tests in the general population. Intervention protocols for type 1 diabetes can then be extended from including only relatives of patients to including the general population, dramatically increasing the range of their benefit.