Wiskott-Aldrich Syndrome

Wiskott-Aldrich syndrome is an immune deficiency disorder in which not enough immunoglobulin M (IgM) is produced by the body. Wiskott-Aldrich syndrome also causes low numbers of blood platelets (thrombocytopenia) which are also small in size, eczema, and an increased risk of developing an autoimmune disorder or cancer. Wiskott-Aldrich syndrome is associated with a defective gene on the X (female) chromosome, so females tend to be carriers of the syndrome while males with the defective gene develop symptoms. Studies have shown that Wiskott-Aldrich syndrome occurs in 4 per million live male births, and affects people of all ethnic backgrounds.

Symptoms
The symptoms of Wiskott-Aldrich syndrome are related to the main effects of the syndrome on the body:

• Immune deficiency leaves the body vulnerable to infection. There may be serious infections such as pneumonia, meningitis, and blood poisoning (sepsis).
• Blood platelets are required for blood clotting, so low numbers of platelets can result in bloody diarrhea, prolonged bleeding from a cut or surgery, or unusual bruises on the body.
• Eczema, a skin disorder, develops in more than three-quarters of individuals with Wiskott-Aldrich syndrome. Individuals with the syndrome may be more allergy-prone and may develop asthma.

As many as 40% of individuals with Wiskott-Aldrich syndrome may develop an autoimmune disorder, with the most common being autoimmune hemolytic anemia, vasculitis, renal disease, arthritis, and Henoch-Schonlein purpura.

Diagnosis
If the symptoms suggest Wiskott-Aldrich syndrome, a test to measure the immunoglobulin in the blood can help confirm the diagnosis and exclude other immune deficiency disorders. Special tests can measure the body's overall immune system function. A complete blood cell count can reveal if there are low numbers of platelets and if they are the small platelets usually found in Wiskott-Aldrich syndrome. Genetic testing can also determine if the defective gene is present. Other tests may be required depending on the particular symptoms an individual has, such as chest x-ray for possible pneumonia.

Treatment
Treatment depends upon the symptoms the individual is experiencing. Low platelets and bleeding may require intravenous immunoglobulin, steroid medication such as prednisone, or blood transfusion. Eczema is treated with skin moisturizers and medicated creams. Infections are treated with the appropriate antibiotics. Individuals affected by Wiskott-Aldrich syndrome must receive close medical care including specialized allergy or immunology care.

So far, the only possible cure for Wiskott-Aldrich syndrome is bone marrow transplantation. A compatible donor is required, and there are risks involved in the transplant. However, if it is successful, the blood and immune defects are corrected and the eczema resolves.

Information for this article was taken from:
- Dibbern, D.A., & Routes, J.M. (2004). Wiskott-Aldrich syndrome. eMedicine, accessed at http://www.emedicine.com/med/topic1162.htm
- Schurman, S.H. (2003). Autoimmunity in Wiskott-Aldrich syndrome. Curr Opin Rheumatol, 15(4), 446-453.