Alport syndrome is a hereditary (genetic) disorder that results in glomerulonephritis in which kidney function is poor, blood is present in the urine, and deafness and eye abnormalities sometimes occur.
(See also Overview of Kidney Filtering Disorders and Glomerulonephritis.)
Alport syndrome is usually caused by a genetic mutation on the X chromosome (female sex chromosome), but it sometimes results from an abnormal gene on a nonsex (autosomal) chromosome. The mutation causes an abnormality in the basement membrane of the glomerulus with leakage of blood cells and protein into the urine. Other factors influence how severe the disorder is in a person who has the genetic mutation. Alport syndrome can cause chronic kidney disease, sometimes with loss of most kidney function (kidney failure).
Symptoms of Alport Syndrome
Females with the genetic mutation on one of their two X chromosomes usually do not have symptoms, although their kidneys may function somewhat less efficiently than normal. Most of these females have some blood in the urine. Occasionally, a female loses most kidney function (kidney failure).
Males with the genetic mutation on their one X chromosome develop more severe problems because males do not have a second X chromosome to compensate for the defect. Males usually develop kidney failure between the ages of 20 and 30, but in some males, the genetic mutation does not cause kidney failure until after age 30.
Alport syndrome can affect other organs. Hearing problems, usually an inability to hear sounds in the higher frequencies, are common. Cataracts can also occur, although less often than hearing loss. Abnormalities of the corneas, lenses, or retina sometimes cause blindness.
Diagnosis of Alport Syndrome
Serum creatinine level
Urinalysis
Kidney biopsy
Molecular genetic analysis
Serum creatinine level is checked to assess kidney function. Urine is tested. Diagnosis is suggested in people who have blood in the urine, particularly if an abnormality of hearing or vision or a family history of chronic kidney disease is present.
Biopsy of the kidney is done.
Sometimes a biopsy of the skin is also done in people who have family members with Alport syndrome to see if they have the same kind of basement membrane abnormalities that occur in the kidney.
Genetic testing is usually offered to people with a family history of kidney disease.
Treatment of Alport Syndrome
Dialysis
There is no specific therapy. People who develop kidney failure need to undergo dialysis or receive a kidney transplant.
