Wiskott-Aldrich syndrome (WA) is a rare X-linked (i.e. inherited) disorder characterized by thrombocytopenia (decreased platelet count), immunodeficiency and eczema. It is estimated to occur in between 1 and 10/million live male births. More than 150 unique gene mutations have been described in families with WAS.
A blood or marrow transplant is the only known cure for WAS. The transplant process utilizes chemotherapy (with or without radiation) to provide immune suppression and to destroy the diseased cells in the bone marrow. The type of transplant used for WAS is an allogeneic transplant where the healthy blood forming cells from the family member donor, unrelated donor or umbilical cord blood unit are used to replace the diseased cells in the bone marrow. These replacement cells are infused into the patient’s blood stream after the patient receives chemotherapy, with or without radiation, where they start making healthy red blood cells, white blood cells and platelets.
Because allogeneic transplant is the only known cure for WAS, it is best to have the transplant early after diagnosis. This is because children with WAS are at risk for dying of severe infections before their transplant provides a working immune system. Thus, a child has a better chance of being cured by a transplant if (1) the transplant is performed soon after diagnosis and (2) the child has not had severe infections.