Screening for Wiskott-Aldrich Syndrome in Chronic Idiopathic Thrombocytopenic Purpura.

The clinical spectrum of X-linked thrombocytopenia (XLT)/ Wiskott-Aldrich syndrome (WAS) is broad, ranging from mild, intermittent thrombocytopenia to the classical severe phenotype characterized by eczema, infections, and thrombocytopenia. Patients with XLT often lack the complete triad but manifest with thrombocytopenia-associated bleeding and are hence misdiagnosed as chronic immune thrombocytopenia (ITP). Moreover, the clinical picture is further complicated by the development of autoimmune cytopenia. Early identification is critical, as definitive treatment with hematopoietic stem cell transplantation (HSCT) can be offered, and unnecessary immunosuppressive therapies, including corticosteroids, can be avoided. In this study, the authors screened a cohort of boys with chronic ITP using flow cytometry-based WASp protein expression analysis, followed by genetic testing. Among 38 patients evaluated, 5 (13.5%) had pathogenic variants in the WAS gene. Clinical features such as X-linked family history, eczema, low mean platelet volume (MPV), or reduced WASp expression in chronic ITP patients with suboptimal response to immunomodulatory drugs should prompt genetic evaluation for WAS.