Alport syndrome

Alternative names:

hematuria - nephropathy - deafness; hemorrhagic familial nephritis; hereditary deafness and nephropathy; hereditary nephritis

Definition:

An inherited (usually X-linked) disorder involving damage to the kidney, blood in the urine, and in some families loss of hearing. The disorder may also include loss of vision.

Causes, incidence, and risk factors:

Alport syndrome is very similar to hereditary nephritis. There may be nerve deafness and congenital eye abnormalities associated with Alport syndrome. The cause is a mutation in a gene for collagen. The disorder is uncommon, affecting about 2 out of 10,000 people.

In women, the disorder is usually mild, with minimal or no symptoms. Women can transmit the gene for the disorder to their children even if the woman has no symptoms of the disorder. In men, the symptoms are more severe and progress faster.

The disorder causes chronic glomerulonephritis with destruction of the glomeruli. Initially, there are no symptoms. Progressive destruction of the glomeruli causes blood in the urine and decreases the effectiveness of the kidney's filtering system. There is progressive loss of kidney function and accumulation of fluids and wastes in the body, with eventual progression to end-stage renal (kidney) disease at an early age. ESRD caused by Alport syndrome often develops between adolescence and age 40.

Risk factors include having a family history of Alport syndrome, nephritis, end-stage renal disease in male relatives, hearing loss before age 30, bloody urine, glomerulonephritis, and similar disorders.