Diabetic nephropathy (DN) is the result of numerous risk factors, such as hyperglycaemia, several genetic polymorphisms, offering susceptibility or individual resistance to DN. There are numerous, well-studied risk factors for DN, the majority being renal extrinsic, but there have been identified and studied renal intrinsic factors (the number of glomeruli, the volume of glomeruli) which can be structural determinants of the risk for the development of DN and may be precocious markers of DN. The clarification of the role of genetic factors in the pathogeny of DN may contribute to the evaluation of DN risk, allowing the selection of patients eligible to new precocious therapies (primary prevention) and the prevention of ESRD (secondary prevention).