Alport Syndrome
Definition
Alport syndrome is a hereditary condition characterized by kidney disease, deafness, and sometimes eye defects. It is involves inflammation of the kidney (nephritis), often progressing to kidney failure, and sensory nerve hearing loss. Progression to kidney failure is gradual and usually occurs in males before 50 years of age. It can also affect the eyes, though the changes do not usually affect sight, except when changes to the lens occur in later life. Blood in urine is universal. Proteinuria is a feature as kidney disease progresses.
The disorder causes progressive deterioration of parts of the kidney and gradual reduction in kidney function. Some types of Alport Syndrome may also affect hearing and vision. The disorder was first identified in a British family by University of Edinburgh Medical School graduate Cecil A. Alport in 1927. Alport Syndrome once also had the label hereditary nephritis, but this is misleading as there are many other causes of hereditary kidney disease and ‘nephritis’.
People with Alport syndrome experience progressive loss of kidney function. Almost all affected individuals have blood in their urine (hematuria), which indicates abnormal functioning of the kidneys. Many people with Alport syndrome also develop high levels of protein in their urine (proteinuria). The kidneys become less able to function as this condition progresses, resulting in end-stage renal disease (ESRD).
Causes, Sign and Symptoms of Alport Syndrome
The cause of Alport syndrome is a mutation in a gene for collagen. The decline in kidney function may progress to the point that dialysis or a kidney transplant may be required, as the kidneys no longer are able to rid the blood of fluids and waste. It most often affects males. Women can pass the gene for the disorder to their children, even if they have no symptoms.
Risk factors are including:
- End-stage kidney disease in male relatives
- Family history of Alport syndrome
- Hearing loss before age 30
The genetic defect associated with Alport syndrome is typically found in the X (male) chromosome. However, women can be carriers of the disease without experiencing any symptoms and may pass the gene defect on to their children. When symptoms are present in women, the effects are usually mild or minimal. In men, the symptoms are much more pronounced and the progression of the disease rapid.
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.
In women, the disorder is usually mild, with few or no symptoms. In men, the symptoms are more severe and get worse faster.
Symptoms include:
- Abnormal urine color
- Ankle, feet, and leg swelling
- Blood in the urine (may be made worse by upper respiratory infections or exercise)
- Decreased or loss of vision (more common in males)
- Flank pain
- Loss of hearing (more common in males)
- Swelling around the eyes
- Swelling overall
Aortic dissection has been described very rarely in patients with early-onset disease. Leiomyomas, tumours of smooth muscle affecting the oesophagus and female genital tract, may occur in a rare overlap syndrome involving the adjacent COL4A5 and COL4A6 genes.
Treatment and Prevantions of Alport Syndrome
The goals of treatment include monitoring and controlling the disease and treating the symptoms. It is most important to strictly control blood pressure. Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers can control blood pressure and slow the rate at which the disease gets worse. In addition to measures for chronic kidney disease (CKD) of any cause, there is evidence that ACE inhibitors can slow the deterioration of kidney function in Alport Syndrome, delaying the need for dialysis or transplantation. The development of proteinuria has been recommended as an indication for commencing treatment.
Hearing loss is likely to be permanent. Counseling and education to increase coping skills can be helpful. Learning new skills such as lip reading or sign language and getting hearing aids may help. Young men with Alport syndrome should use hearing protection in noisy environments. Genetic counseling may be recommended because the disorder is inherited.
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.
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