Diabetic nephropathy is the leading cause of renal failure in industrialized countries. There is strong evidence that diabetic
nephropathy is influenced by genetic factors. Studies in the Pima Indians as well as in other populations demonstrate that
diabetic nephropathy aggregates in families. The hypothesis that the familial aggregation reflects the effect of a major gene
was formally tested by segregation analysis of diabetic nephropathy in Pima Indians with type 2 diabetes.
The segregation analysis provided strong evidence for a major genetic effect on the prevalence of diabetic nephropathy; this
suggests that some of the genetic determinants of diabetic nephropathy may have effects of sufficient magnitude to be detected
by linkage analysis. Therefore, we analyzed data from a genome-wide scan to identify susceptibility loci for nephropathy in
diabetic Pima Indians. Analyses conducted by both parametric (model-based) and nonparametric methods revealed tentative evidence
for nephropathy susceptibility loci on chromosomes 3q, 7q, 18q, and 20p.