Alport syndrome

Alport syndrome is a rare genetic disorder characterized by glomerulonephritis, progression to end stage kidney disease, and hearing loss, with blood in the urine present in essentially all cases and protein appearing in the urine as kidney disease advances. It results from an inherited defect in type IV collagen, a structural material the body needs for normal function of the kidneys, ears and eyes, caused by mutations in the COL4A3, COL4A4 and COL4A5 genes that prevent proper assembly of collagen networks in basement membranes. The disorder occurs in three inheritance forms: X linked, affecting about eighty five percent of patients, autosomal recessive, and autosomal dominant; males with the X linked form typically develop more severe disease, while affected females often have milder symptoms. Physician Cecil A. Alport first identified the condition in a British family in 1927; it was previously called hereditary nephritis, a term now considered misleading since other hereditary kidney diseases exist. Alport syndrome affects around one in five thousand to ten thousand children, making it relatively common among genetic disorders despite its rare disease classification.