What is Alport syndrome?
Alport syndrome is a disease that damages the tiny blood vessels in your kidneys. It can lead to kidney disease and kidney failure. It can also cause hearing loss and problems within the eyes. Alport syndrome causes damage to your kidneys by attacking the glomeruli. Glomeruli are the tiny filtering units inside your kidneys.
What causes Alport syndrome?
Alport syndrome is an inherited disease, which means it is passed down through families. It is caused by changes in your genes (mutations) to a protein called collagen. Collagen is important to the normal structure and function of the kidneys. Changes to collagen can also cause problems with the eyes and ears. That’s because collagen helps maintain healthy tissue in the eyes and ears.
What are the genetic types of Alport syndrome?
There are three genetic types of Alport syndrome.
- X-linked Alport syndrome (XLAS)
- Autosomal recessive Alport syndrome (ARAS)
- Autosomal dominant Alport syndrome (ADAS)
X-linked Alport syndrome: X-linked (related to the X chromosome) is the most common form of Alport Syndrome. About 80% of the people with this disease have the X-linked type. Without treatment, 90% of males develop kidney failure by 40 years old. Females develop kidney failure less frequently and more slowly.
Autosomal recessive Alport syndrome (ARAS): This is when both parents carry the abnormal gene and both parents pass the abnormal gene to the child. Both copies of the abnormal gene are needed to cause the autosomal recessive type of Alport Syndrome.
Autosomal dominant Alport syndrome (ADAS): This happens when one parent has the disease and passes the abnormal gene to the child. In other words, only one copy of the abnormal gene is needed to cause the disease.
What are the signs and symptoms of Alport syndrome?
With all types of Alport syndrome the kidneys are affected. The tiny blood vessels in the glomeruli of the kidneys are damaged and cannot filter the wastes and extra fluid in your body. Many people with Alport syndrome also have hearing problems and abnormalities with their eyes.
Other signs and symptoms may include:
- Blood in the urine (hematuria), the most common and earliest sign of Alport syndrome
- Protein in the urine (proteinuria)
- High blood pressure (hypertension)
- Swelling in the legs, ankle, feet and around the eyes (called edema)
These signs and symptoms may differ, based on age, gender and inherited type of Alport syndrome.
How is Alport syndrome diagnosed?
Your healthcare professional will have to watch your signs, symptoms, and look at your family history to know if you have Alport syndrome. The following tests or exams may be done to help your healthcare professional make a diagnosis:
- Urine test: A urine test will help find protein and blood in your urine.
- Blood test: A blood test will help find levels of protein, and wastes in your blood.
- Glomerular filtration rate (GFR): A blood test will be done to know how well your kidneys are filtering the wastes from your body.
- Kidney biopsy: In this test, a tiny piece of your kidney is removed with a special needle, and looked at under a microscope.
- Hearing test: A hearing test will be done to see if your hearing has been affected.
- Vision test: A vision test will be done to see if you vision has been affected.
- Genetic test: This can help confirm the diagnosis and determine the genetic type of Alport syndrome you may have.
How is Alport syndrome treated?
Currently, there is no specific treatment for Alport syndrome. The goal is to treat the symptoms and help slow the progression of kidney disease. This may include:
- ACE inhibitor or ARB medicines (medications to control high blood pressure)
- Diuretics (water pills)
- Limit sodium (salt) in your diet
If you are approaching kidney disease because of Alport syndrome, a kidney transplantation is usually very successful in people with Alport syndrome and is considered the best treatment when kidney failure is approaching.