The clinical features in Alport syndrome are explained because the COL4A5 and COL4A3/COL4A4 genes code for the collagen IV α5 chain, α3 and α4 chains which form a heterotrimer in the basement membranes of the glomerulus, cochlea and eye [10] (Table 1). The gene discussed is COL4A4; the disease is Alport syndrome.