Intermittent X-linked thrombocytopenia with a novel WAS gene mutation.

X-linked thrombocytopenia (XLT) is caused by mutations in the WAS gene and characterized by thrombocytopenia with minimal or no immunodeficiency. Patients with XLT usually exhibit persistent thrombocytopenia, and intermittent thrombocytopenia has been described only in two families. Here, we report a patient with intermittent XLT carrying a novel missense mutation (Ala56Thr). He showed residual expression of Wiskott-Aldrich syndrome protein in the lymphocytes and platelets. There appeared to be an association between normal platelet numbers and a post infectious state. Our findings further support the importance of analysis of Wiskott-Aldrich syndrome protein in male patients who exhibit fluctuating courses of thrombocytopenia.