Alport syndrome is a genetic condition characterized by the progressive loss of kidney function and hearing. Alport syndrome can also affect the eyes. The presence of blood in the urine (hematuria) is almost always found in this condition. Many people with Alport syndrome also exhibit high levels of protein in their urine (proteinuria). As this condition progresses, the kidneys become less able to function properly and kidney failure results. Hearing loss is a common feature of Alport syndrome, but the abnormalities in the eyes seldom lead to loss of vision.

The disorder damages the tiny blood vessels in the kidneys, called glomeruli, that filter wastes. At first, there are no symptoms. Then the progressive destruction of the glomeruli leads to blood in the urine and decreases the effectiveness of the kidney's filtering system. There is a progressive loss of kidney function and a build-up of fluids and wastes in the body. In women, the disorder is usually mild, with minimal or no symptoms. In men, the symptoms are more severe and get worse faster.

Alport syndrome is caused by mutations in COL4A3, COL4A4, and COL4A5, collagen biosynthesis genes. Mutations in any of these genes prevent the proper production or assembly of the type IV collagen network, which is an important structural component of basement membranes in the kidney, inner ear, and eye. Basement membranes are thin, sheet-like structures that separate and support cells in many tissues. When mutations prevent the formation of type IV collagen fibers, the basement membranes of the kidneys are not able to filter waste products from the blood and create urine normally, allowing blood and protein into the urine. The abnormalities of type IV collagen in kidney basement membranes cause gradual scarring of the kidneys, eventually leading to kidney failure in many people with the disease.

The first subtle manifestations of classical Alport Syndrome (XLAS) usually appear early in life. Blood in the urine (hematuria) may be detectable by one year of age in about 15% of cases, and by six years of age in about 70% of cases. Occasionally, there may be brief episodes lasting for days during which the blood is visible to the eye; pain or other symptoms do not accompany these episodes. Leak of protein in the urine is not usually evident in infancy, but increases during the first two decades.

The Alport Syndrome Foundation is an organization formed in 2007 by families affected by this disease. We are a non-profit corporation but are essentially a group of concerned families and friends that found it difficult to locate concise, useful and easy to understand information about this disease on the web. We recognize that there is a lot of information available, but it is often technical, confusing, and overwhelming - especially to those who are newly diagnosed.

The most common mutation involves substitution for glycine in the collagenous domain of the a5(IV) chain by a bulky amino acid, resulting in protein-folding abnormalities. Alport syndrome, affecting about one in 5,000 persons, is hereditary glomerulonephritis that is caused by mutation of one or the other of several COL4A genes that specify chains of basement membrane (Type IV) collagen, or by mutation of unknown genes. Especially in males, the resultant chronic nephritis progresses via uremic syndrome to end-stage renal disease treatable only by dialysis or by kidney transplantation. In various families, nephritis may be associated with various combinations of hearing loss, lenticonus and other eye disorders, immunologic abnormality of skin, disorders of platelets, abnormalities of white blood cells, or smooth muscle tumors.