Alport syndrome Dr Trisha Macnair Those affected by Alport syndrome develop progressive loss of renal (kidney) function, and sometimes progressive deafness and abnormalities of the eye.

In this article

What is it? Who's affected?

How is it diagnosed? What's the treatment?

Alport syndrome is the second most common inherited cause of kidney failure. There are many other, much more common, non-inherited causes of kidney failure, such as diabetes, high blood pressure and glomerulonephritis (inflammation of the kidney that may develop for a variety of reasons). It occurs when a special type of collagen normally found in the kidney is missing or abnormal.

One of the early signs of Alport syndrome may be small amounts of blood or protein in the urine during childhood.

It's more common among males

About one in 5,000 children is affected by Alport syndrome. Because of the way in which it's inherited, it's more common among males.

The gene that causes most cases (called COL4A5) is on the X chromosome. Women have two X chromosomes, so they usually have a healthy gene as well as the faulty one, but men don't have a healthy X chromosome because they have X and Y chromosomes. Women who carry the faulty gene may have minor kidney problems but sometimes may have more serious kidney disease.

In some cases, a different gene, inherited in an autosomal dominant fashion, is to blame. For 15 to 20 per cent of sufferers who don't have a family history of the disease, it's caused by a gene mutation.

Diagnosis is difficult because of similarities with other kidney diseases. A kidney biopsy can be carried out.

The gene is difficult to detect, although genetic testing may be possible in families where the problem has already been thoroughly studied.

Treatment consists of controlling high blood pressure and restricting salt, protein and phosphate in the diet. Eventually, dialysis and kidney transplant may be necessary.

This article was last medically reviewed by Dr Rob Hicks in October 2007