[Genetics of diabetic complications: nephropathy]

Diabetic nephropathy is present in 35 to 45% of Type 1 diabetic patients after 15-20 yrs of diabetes duration. Glycaemic control and diabetes duration are the major risk factors for diabetic nephropathy. Hypertension which is twice as common in diabetics than in the general population, as well as ethnic origin play an important role too. However, as not all diabetic patients will develop diabetic nephropathy, this support the hypothesis for factors of genetic susceptibility (or of protection!) to diabetic nephropathy. Familial aggregation studies supporting this concept of genetic susceptibility, and studies on candidate genes polymorphisms and their association (or lack of association) with diabetic nephropathy (angiotensin-converting enzyme, angiotensinogen and atrial natriuretic peptide genes) are reviewed. Available data from candidate genes studies support a possible implication of vasoactive genes polymorphisms in the development of diabetic nephropathy, but the risk appears to be weak. Ongoing and future studies should aim to detect gene polymorphisms with strong effects, or to identify the association and/or interaction between polymorphisms and diabetic nephropathy.