(See also Overview of Kidney Filtering Disorders Overview of Kidney Filtering Disorders Each kidney contains about 1 million filtering units (glomeruli). The glomeruli are made up of many microscopic clusters of tiny blood vessels (capillaries) with small pores. These blood vessels... read more and Glomerulonephritis Glomerulonephritis Glomerulonephritis is a disorder of glomeruli (clusters of microscopic blood vessels in the kidneys with small pores through which blood is filtered). It is characterized by body tissue swelling... read more .)
Alport syndrome is usually caused by a defective gene on the X chromosome (female sex chromosome), but it sometimes results from an abnormal gene on a nonsex (autosomal) chromosome. Other factors influence how severe the disorder is in a person who has the defective gene. Alport syndrome can cause chronic kidney disease Chronic Kidney Disease Chronic kidney disease is a slowly progressive (months to years) decline in the kidneys’ ability to filter metabolic waste products from the blood. Major causes are diabetes and high blood pressure... read more , sometimes with loss of most kidney function (kidney failure).
Females with the defective gene 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 Overview of Kidney Failure This chapter includes a new section on COVID-19 and acute kidney injury (AKI). Kidney failure is the inability of the kidneys to adequately filter metabolic waste products from the blood. Kidney... read more ).
Males with the defective gene 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 defective gene 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 Cataract A cataract is a clouding (opacity) of the lens of the eye that causes a progressive, painless loss of vision. Vision may be blurred, contrast may be lost, and halos may be visible around lights... read more can also occur, although less often than hearing loss. Abnormalities of the corneas, lenses, or retina sometimes cause blindness.
Molecular genetic analysis
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 Chronic Kidney Disease Chronic kidney disease is a slowly progressive (months to years) decline in the kidneys’ ability to filter metabolic waste products from the blood. Major causes are diabetes and high blood pressure... read more is present.
Biopsy of the kidney Tissue and Cell Sampling Site-specific biopsies and cell sampling are also used in the evaluation of people with suspected kidney and urinary tract disorders. (See also Overview of the Urinary Tract.) A kidney biopsy... read more is done. Sometimes a biopsy of the skin is also needed in people who have family members with Alport syndrome.
Genetic testing is usually offered to people with a family history of kidney disease.
There is no specific therapy. People who develop kidney failure need to undergo dialysis Dialysis Dialysis is an artificial process for removing waste products and excess fluids from the body, a process that is needed when the kidneys are not functioning properly. There are a number of reasons... read more or receive a kidney transplant Kidney Transplantation Kidney transplantation is the removal of a healthy kidney from a living or recently deceased person and then its transfer into a person with end-stage kidney failure. (See also Overview of Transplantation... read more .