[Contribution of molecular biology to the diagnosis of monogenic hereditary nephropathies].

Schematically, gene identification can be achieved by functional cloning, based on preexisting knowledge about the basic biochemical defect, positional cloning, initiated by the mapping of the responsible gene to its correct location on a chromosome, or by a combination of these two approaches called "candidate gene" approach. Genes of numerous monogenic hereditary renal disorders have been identified during the last few years by one of these approaches, particularly, the PKD1 and PKD2 genes involved in autosomal dominant polycystic kidney disease, as well as the genes encoding different type IV collagen alpha chains, responsible for Alport syndrome. This allows novel insights in the understanding of the pathogenesis of hereditary renal diseases and has opened new areas of genetic diagnosis.