[Alport's syndrome: new findings].

The Alport's syndrome is a disease characterized by a symptomatic triad: nephropathy, hypoacusia and ocular alterations. This syndrome is genetically heterogeneous and results from numerous mutations in COL4A5 gene, whose locus resides on the long arm of the X chromosome (Xq22). This gene codifies for IV collagen alpha 5 chain, which is a fundamental constituent of the glomerular, lens and Corti's organ basal membranes. Present knowledge on molecular genetics and the characterization of the different mutations that affect the Alport's gene will lead to classification of this syndrome in subtypes, according to those mutations, and to its phenotypic expressions; in addition, some syndromes, phenotypically similar, will probably have to be distinguished from Alport's disease, in a future, if a genetic alteration is found in genes other than COL4A5.