Alport syndrome (OMIM, X-LINKED, TS1, # 301050; AUTOSOMAL RECESSIVE, TS2, # 203780; AUTOSOMAL DOMINANT, TS1, # 104200) is caused by mutations in COL4A3/4/5 genes, which encode type IV collagen α3/4/5 chains (α3 chain, UniProt Q01955; α4 chain, P53420; α5 chain, P29400). This evidence concerns the gene COL4A3 and Alport syndrome.