Wiskott-Aldrich Syndrome protein (WASp) regulates the cytoskeleton in hematopoietic cells and mutations in its gene cause the Wiskott-Aldrich Syndrome (WAS), a primary immunodeficiency with microthrombocytopenia, eczema and a higher susceptibility to develop tumors.
Non-haematological features, such as eczema (n = 7) and bloody stools (n = 6), ultimately led to the diagnosis of WAS at a median age of 4 months (range, 3-8 months), which was confirmed by absent (n = 6) or reduced (n = 1) WASP expression in lymphocytes by flow cytometry (FCM) and a WASP gene mutation.
Lack of WASP expression was associated with susceptibility to bacterial, viral, fungal, and Pneumocystis carinii infections and with severe eczema, intestinal hemorrhage, death from intracranial bleeding, and malignancies.