Primary Immune Deficiency Treatment Consortium

Learn More - Wiskott-Aldrich Syndrome (WAS)

What is Wiskott-Aldrich Syndrome (WAS)?

Wiskott-Aldrich Syndrome (WAS) is a serious medical condition that causes problems both with the immune system and with blood clotting. Patients with WAS may be very susceptible to infections caused by bacterial and fungal organisms and eczema. The problems with easy bruising and bleeding in patients with WAS result from having low counts of small, non-functional platelets, the cells in the blood that clump together to form blood clots.

Children with WAS are diagnosed most commonly in the first 1-2 years of life because of easy bruising, abnormal bleeding, or low platelet counts. Patients may also have severe or frequent infections, including bacterial ear infections, sinus infections, pneumonia, blood infections, or viral infections.
Patients show a wide variation in the severity of the disease and four types have been identified:

  1. Classic or Severe WAS: This is the most severe form of WAS.
  2. X-Linked Thrombocytopenia (XLT): This is milder form of WAS where the plateletsare affected but there is little or no immunodeficiency. Sometimes the symptoms of WAS and XLT overlap, making the distinction between the two unclear. 
  3. Intermittent Thrombocytopenia: The mildest form called where the platelet abnormalities are intermittent and there is no immunodeficiency.
  4. X Linked Neutropenia: This is the rarest form in which the platelets are normal but there is a serious defect in the neutrophils (a kind of white blood cell). Patients can have serious and recurrent infections.

Symptoms of WAS vary among patients. Individuals with classic WAS may have bleeding, frequent infections, eczema and often develop autoimmune disorders or malignancy. Individuals with XLT may have just bleeding manifestations or may have eczema. The symptoms typically present at birth or in infancy.

What causes WAS?

WAS is caused by a mutation in the WAS gene that is located on the X chromosome. The production of the WAS protein is controlled by the WAS gene. This gene instructs cells to make the WAS protein. When this gene is mutated, it results in patients having abnormal, reduced or absent protein causing WAS.

Who gets WAS?

WAS is an X-linked disorder. In X-linked disorders, females may carry the gene for the disorder but don’t develop symptoms, whereas boys develop the clinical problems associated with the disease. WAS is estimated to occur in approximately 1 out of every 100,000 boys.1

How is WAS Diagnosed?

The diagnosis of WAS should be considered in any boy with unusually increased bruising or bleeding, particularly if it was noticed soon after birth or in infancy. Additional criteria include recurrent bacterial, viral infections in infancy and early childhood, eczema, the presence of autoimmune disorders or lymphoma. There may be a family history of similar symptoms among brothers, cousins or maternal uncles.
Once the diagnosis of WAS is clinically considered, the following laboratory tests may be ordered:.

What is the treatment for WAS?

When a boy has been diagnosed with WAS, there are several possible treatment  options. Physicians and parents choose different treatment options according to the severity of the diseases. Physicians review individual cases and make recommendations on the treatment options that are most suitable

Treatment for WAS may include the following: