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Alport syndrome
Definition
Alport syndrome is an inherited disorder that damages the tiny blood vessels in the kidneys.
Alternative Names
Hereditary nephritis; Hematuria - nephropathy - deafness; Hemorrhagic familial nephritis; Hereditary deafness and nephropathy
Causes
Alport syndrome is an inherited form of kidney inflammation (nephritis). It is caused by a mutation in a gene for a protein in the connective tissue, called collagen.
The disorder is uncommon. It most often affects males. Women can pass the gene for the disorder to their children, even if they have no symptoms.
Risk factors include:
- End-stage kidney disease in male relatives
- Family history of Alport syndrome
- Hearing loss before age 30
Symptoms
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.
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
The condition can progress to end-stage renal disease (ESRD) at an early age (between adolescence and age 40).
Note: There may be no symptoms in some cases. Symptoms of chronic kidney failure or heart failure may be present or may develop.
Exams and Tests
Signs include:
- Changes to the eye, including the fundus (back inner part of the eye), cataracts, or bulging of the lens (lenticonus)
- High blood pressure
The following tests may be done:
Treatment
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.
You may need to treat chronic kidney disease. This can include changing the diet, limiting fluids, and other treatments. Chronic kidney disease will progress to end-stage kidney disease. This will require dialysis or a kidney transplant.
Surgery to repair cataracts (cataract extraction) or a bulging of the lens in the eye may be needed.
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.
Outlook (Prognosis)
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.
In men, deafness, vision problems, and end-stage kidney disease are likely by age 50.
Possible Complications
- Chronic kidney disease
- Deafness
- Decrease or loss of vision
- End-stage renal disease
When to Contact a Medical Professional
Call for an appointment with your health care provider if:
- You have symptoms of Alport syndrome
- You have a family history of Alport syndrome and you are planning to have children
- Your urine output decreases or stops or you see blood in your urine (this may be a symptom of chronic kidney disease)
Prevention
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.
References
Appel GB, Radhakrishnan J, D'Agati V. Secondary glomerular disease. In: Brenner BM, ed. Brenner and Rector's the Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 31.
Pan CG, Avner ED. Isolated glomerular disease with recurrent gross hematuria. In: Kliegman REm Stanton BF, St. Geme JW III, Schor NF, Behrman RE, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 504.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Herbert Y. Lin, MD, PHD, Nephrologist, Massachusetts General Hospital; Associate Professor of Medicine, Harvard Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
