Genetics of diabetes complications.

Long-term exposure to the hyperglycemia characteristic of diabetes patients leads to serious and frequently disabling or fatal complications. Emerging evidence suggests that genes are a significant contributor to an individual's risk of developing complications. This evidence is from evaluations of familial aggregation, differences in incidence in racial and ethnic groups, and statistical analysis of family data. Evidence to date suggests that complication genes are, distinct from the genes contributing to diabetes. Molecular geneticists have taken several approaches to identify genes contributing to complications, ranging from relatively simple analysis of specific candidate genes in small case-control comparisons to systematic evaluations of the human genome using genome scans and linkage analysis in large collections of families. Results suggest that genetic contributions to diabetes complications are diverse and complex in nature, presenting a significant challenge to researchers. Diabetes-affected families are frequently enriched for complications such as cardiovascular disease or nephropathy. In addition to their value in the study of diabetes complications, such families may be valuable resources for understanding cardiovascular disease and nephropathy in the nondiabetic population also.