Genetics of Diabetic Nephropathy: Are There Clues to the Understanding of Common Kidney Diseases?

Diabetic nephropathy is the most common cause of end-stage renal disease in the Western world. There is evidence for a genetic susceptibility to diabetic kidney disease, but despite intensive research efforts it has proved difficult to identify the causative genes. Improvements in genotyping technologies have made genome-wide association studies (GWAS), employing hundreds of thousands of single nucleotide polymorphisms, affordable. Recently, such scans have advanced understanding of the genetics of common complex diseases, finding more than 100 novel susceptibility variants for diverse disorders including type 1 and 2 diabetes, coronary heart disease, Crohn's disease and rheumatoid arthritis. In this review, type 2 diabetes is highlighted to illustrate how genome-wide association studies have been used to study the genetics of complex multifactorial conditions; in addition, diabetic nephropathy will be used to demonstrate how similar scans could be employed to detect genetic factors predisposing to kidney disease. The identification of such variants would permit early identification of atrisk patients, enabling targeting of therapy and a move towards primary prevention. In addition, these powerful research methodologies may identify genes that were not previously known to predispose to nephropathy, thereby enhancing our understanding of the pathophysiology of renal disorders and potentially leading to novel therapeutic approaches.