[Contribution of genetics to knowledge and management of hereditary kidney diseases progressing to renal failure]

Genes of most of the hereditary renal diseases progressing to renal insufficiency are now identified. In the first part of this paper we describe their multi-faceted genetics. Genetic heterogeneity has been demonstrated in many of these diseases, such as Alport's syndrome and nephronophtisis. In some of them an allelic heterogeneity is present as in the X-linked form of Alport's syndrome (more than 300 different mutations have been described along the COL4A5 gene). Besides these classical mendelian diseases, mendelian subentities have been isolated within common diseases such as cortico-resistant nephrosis. Many diseases also demonstrate a variability of their phenotype resulting from allelic and/or genetic heterogeneity, or from modifier genes. In the second part of the paper we discuss the consequences of this explosion of knowledge with respect to epidemiology, genetic diagnosis, prenatal diagnosis and treatment.