AD Alport syndrome is characterised by haematuria or blood in the urine and a thinned glomerular basement membrane in the kidney biopsy. Protein in the urine (proteinuria) occurs in a few, and sometimes kidney failure occurs. Hearing loss and ocular abnormalities do not occur. AD Alport syndrome occurs in successive generations, and males and females are affected equally often and equally severely.
AR Alport syndrome occurs equally often and equally severely in males and females. The clinical features are identical to those seen in males with XL Alport syndrome. Haematuria is found in all affected people. Proteinuria occurs commonly and kidney failure is present at a young age in both males and females. Hearing loss, and ocular abnormalities (lenticonus; and fleck retinopathy) are common. AR Alport syndrome usually only occurs in a single generation, but the parents and offspring have AD Alport syndrome and haematuria. AR Alport syndrome is more common in the children of consanguineous parents (where the parents are first or second cousins) or where a mutation in COL4A3 or COL4A4 is more common in people of a certain ancestry. AR Alport syndrome should also be suspected where a girl develops kidney failure, especially together with hearing loss, or lenticonus and a fleck retinopathy.
COL4A3