Alport syndrome (AS) is a clinically and genetically heterogeneous disease, characterized by renal, cochlear, and ocular involvement.  Renal disease progresses from microscopic hematuria to proteinuria, progressive renal insufficiency, and end-stage renal disease (ESRD).  It accounts for 3% of end-stage renal failure (ESRF) in childhood and is the most common of several types of hereditary nephritis. The pattern of inheritance is variable and may be either: X-linked dominant (85%), autosomal recessive (15%), or autosomal dominant (<1%). Autosomal dominant Alport syndrome is rare, and the clinical phenotype differs from that seen with X-linked and autosomal recessive inheritance. Autosomal dominant AS is characterized by haematuria, renal failure and sensorineural hearing loss, but ocular abnormalities do not occur. 

The diagnosis of autosomal dominant AS depends on the presence of typical clinical features, family history of the disease, or on the ultrastructural demonstration of a lamellated glomerular basement membrane. Different mutations in type IV collagen genes can result in a spectrum of phenotypes of Alport syndrome.  Mutations in COL4A3 and COL4A4 genes, which are localized on chromosome 2, are responsible for the autosomal dominant and autosomal recessive forms of the syndrome.