Alport syndrome facts*
*Alport syndrome facts medical author: Melissa Conrad Stöppler, MD
- Alport syndrome is a genetic (inherited) disease.
- Signs and symptoms of Alport syndrome include hearing loss, eye problems, and blood in the urine, signifying loss of kidney function.
- Alport syndrome occurs in 1 out of 50,000 newborns.
- Mutations in the genes COL4A3, COL4A4, and COL4A5 cause Alport syndrome. These genes code for proteins responsible for the formation of a component of collagen Type IV.
- Different patterns of genetic inheritance have been observed in Alport syndrome.
- About 80% of cases of Alport syndrome are inherited in an X-linked manner (meaning the gene defect is on the X chromosome). About 15% of cases show autosomal recessive inheritance, and about 5% of cases are inherited in an autosomal dominant manner.
- Congenital hereditary hematuria is another name for Alport syndrome.
What is Alport syndrome?
What are the signs and symptoms of Alport syndrome?
People with Alport syndrome experience progressive loss of kidney function. Almost all affected individuals have blood in their urine (hematuria), which indicates abnormal functioning of the kidneys. Many people with Alport syndrome also develop high levels of protein in their urine (proteinuria). The kidneys become less able to function as this condition progresses, resulting in end-stage renal disease (ESRD).
People with Alport syndrome frequently develop sensorineural hearing loss, which is caused by abnormalities of the inner ear, during late childhood or early adolescence. Affected individuals may also have misshapen lenses in the eyes (anterior lenticonus) and abnormal coloration of the light-sensitive tissue at the back of the eye (retina). These eye abnormalities seldom lead to vision loss.
Significant hearing loss, eye abnormalities, and progressive kidney disease are more common in males with Alport syndrome than in affected females.