Genetic Approach for Insulin-Independent Diabetes Mellitus in Clinical Practice

Insulin-independent diabetes mellitus (IDDM) is a polygenic disease with an environmental component. Technological advances and large collection families allowed genetic factors understanding. On clinical practice, two questions could be asked. First, will the genetic markers be of interest in disease prediction either in family studies or in the main population? Secondly, will the genetic approach explain the physiopathological process of the disease? Initially, the gene candidate approach led to the identification of two important loci: Linkage with the human leukocyte antigen (HLA) locus showed the importance of the autoimmune part. Linkage of insulin-independent diabetes mellitus with insulin locus gave a mechanistic answer for disease susceptibility. These two loci can be used as prediction markers, but only in family studies. Since 1993, a whole genome approach has been performed and has led to the identification of other susceptibility loci. These initial results are in progress and should have important implications for public health strategies.