What is Wiskott-Aldridge Syndrome?
Wiskott-Aldrich syndrome is a primary immunodeficiency disorder. A person with this condition has an immune system that does not work properly to protect the body from infections.
Children with Wiskott-Aldrich syndrome are also at risk for the following:
- infections
- autoimmune diseases (conditions in which the immune cells mistakenly attack a person’s own normal body cells, tissues and organs)
- lymphoma, a cancer of the immune system cells
- bleeding problems
Wiskott-Aldrich syndrome belongs to a larger family of conditions called WAS-related disorders. These conditions are all caused by harmful changes (mutations) in a gene called WAS. The WAS gene is located on the X chromosome, which is one of the two types of sex chromosomes. Therefore, Wiskott-Aldrich syndrome is known as an “X-linked disorder.”
X-linked disorders generally only affect males, not females. A male has one X chromosome and one Y chromosome. A female has two X chromosomes. A boy with Wiskott-Aldrich syndrome has a mutation in the WAS gene on his X chromosome, and no WAS gene on his Y chromosome. A girl may have a mutation in the WAS gene on one of her X chromosomes, but she will also have a normal WAS gene on the other X chromosome. She will not have Wiskott-Aldrich syndrome. She is a carrier for the condition. This means when she grows up and has children, she can pass the mutated WAS gene on to them.
How common is Wiskott-Aldrich syndrome?
Wiskott-Aldrich syndrome is very rare, occurring in about one out of every 100,000 live births.
What are the symptoms of Wiskott-Aldrich syndrome?
Symptoms of Wiskott-Aldrich syndrome include:
- Having many bacterial or viral infections as an infant or a young child
- Eczema (red, scaly, itchy patches of skin)
- Lymphoma (cancer of the immune system cells)
- Autoimmune diseases (conditions in which the immune cells attack a person’s own normal body cells, tissues and organs)
- Excessive bleeding and blood that takes too long to clot. This is caused by thrombocytopenia (too few platelets in the blood). Platelets are the cells in blood that form blood clots.
How is Wiskott-Aldrich syndrome treated?
Antibiotics and immunoglobulins: While children with Wiskott-Aldrich syndrome await transplants, they may need treatment for symptoms of the condition. Infections are usually treated with antibiotics. The risk of infection can be reduced by giving the child regular doses of immunoglobulins. These healthy immune cells collected from blood donors are given to the patient through a vein.
Immunosuppressants: Children with autoimmune conditions may need immunosuppressants. These medicines help prevent a patient’s abnormal immune cells from attacking the body’s healthy cells.
Transfusions: Sometimes a child with Wiskott-Aldrich syndrome who has excessive bleeding may need a transfusion of platelets from a healthy donor. Healthy platelets help the child’s blood to clot more quickly.
Bone marrow transplant: The most effective treatment for Wiskott-Aldrich syndrome is a bone marrow transplant. Immune cells are formed in the bone marrow by bone marrow stem cells. A bone marrow transplant gives the person with Wiskott-Aldrich syndrome new stem cells from a healthy donor’s bone marrow. Bone marrow stem cells can live for a long time. They make healthy immune cells to replace the missing or non-working immune cells.
A bone marrow transplant is most successful for curing Wiskott-Aldrich syndrome when the donor is “tissue matched” to the person with Wiskott-Aldrich syndrome. Every person has a tissue type, which is also called an HLA type. HLA stands for human leukocyte antigen, a marker your immune system uses to recognize which cells belong in your body and which do not. An ideal bone marrow donor has an HLA type that matches the HLA type of the person with Wiskott-Aldrich syndrome. Sometimes, the patient’s sister or brother will be a match and can be the donor. Patients without matched sibling donors may have transplants from parents or unrelated matched donors.
If an ideal bone marrow donor cannot be found, then sometimes donor stem cells from umbilical cord blood can be used instead. These stem cells can also work for a long time in the body to make healthy immune cells
What are the survival rates for Wiskott-Aldrich syndrome?
Long-term survival after bone marrow transplant for children with Wiskott-Aldrich syndrome is over 80%. Children who are less than 2 years old at the time of the transplant have the best outcome, with survival rates over 90%.
