Alport Syndrome

Definition

Definition of Alport Syndrome
Alport syndrome or hereditary nephritis is a genetic disorder characterized by glomerulonephritis, endstage kidney disease, and hearing loss. Alport syndrome can also affect the eyes (lenticonus). The presence of blood in the urine (hematuria) is almost always found in this condition.

Symptoms

Symptoms of Alport Syndrome
The disorder damages the tiny blood vessels in the glomeruli of the kidneys. The glomeruli filter blood to make urine and remove waste products from the blood.

At first, there are no symptoms. However, the destruction of the glomeruli over time leads to blood in the urine and may decrease the effectiveness of the kidney's filtering system. Often kidney function is lost over time and waste products and fluids build up in the body.

Symptoms include:

1. Abnormal urine color
2. Ankle, feet, and leg swelling
3. Blood in the urine (may be made worse by upper respiratory infections or exercise)
4. Decreased or loss of vision (more common in males)
5. Flank pain
6. Loss of hearing (more common in males)
7. Swelling around the eyes
8. Swelling overall

Causes

Causes of Alport Syndrome
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.

Diagnosis

Diagnosis of Alport Syndrome

1. Changes to the eye, including the fundus (back inner part of the eye), cataracts, or bulging of the lens (lenticonus)
2. High blood pressure

Treatment

Treatment of Alport Syndrome
As there is no known cure for the condition, treatments are symptomatic. Patients are advised on how to manage the complications of kidney failure and the proteinuria that develops is often treated with ACE inhibitors, although they are not always used simply for the elevated blood pressure.

Once kidney failure has developed, patients are given dialysis or can benefit from a kidney transplant, although this can cause problems. The body may reject the new kidney as it contains normal type IV collagen, which may be recognized as foreign by the immune system.

Prognosis

Prognosis of Alport Syndrome
Women usually have a normal lifespan with no signs of the disease except for blood in the urine. Rarely, women will have high blood pressure, swelling, and nerve deafness as a complication of pregnancy.

Prevention

Prevention of Alport Syndrome
This uncommon disorder is inherited. Awareness of risk factors, such as a family history of the disorder, may allow the condition to be detected early.