Genetics and the prediction of complications in type 1 diabetes

Epidemiological evidence suggests that genetic factors can affect the course of type 1 diabetes complications produced by long-lasting hyperglycemia. In this review, the current strategies applicable to identifying these genetic factors are examined, as are recent findings on the genetics of diabetic nephropathy and whether these are applicable to type 1 diabetes patient care.

Whole-genome screening and candidate gene strategies can be applied to the genetics of type 1 diabetes complications. The search for candidate genes can focus on enzymes involved in glucose metabolism or on those affecting non-glycemic-dependent vascular risk. For each candidate, the level of evidence may vary from case-control to intervention studies. Literature on diabetic complications and a possible role for genetics was examined systematically.

The most significant results were obtained regarding a role for polymorphisms of the renin-angiotensin system in diabetic nephropathy. Several studies suggest a role for angiotensin I converting enzyme insertion/deletion polymorphism in the development of renal complications. However, the level of evidence is currently not sufficient to recommend treatment strategy based on this or any other polymorphism.

The search for a genetic basis of type 1 diabetes complications is an important avenue to examine their pathophysiologies. However, it is still premature to apply the current findings in this domain to type 1 diabetes patient care.