A 12-month-old infant with a history of recurrent infections, eczema, generalized edema, and easy bruising is diagnosed with an X-linked, recessive, congenital immunodeficiency. The CBC shows thrombocytopenia. What is the most likely diagnosis?
High-Yield Explanation
Wiskott-Aldrich syndrome. This rare syndrome is characterized by (1) recurrent infections, (2) hemorrhages secondary to thrombocytopenia, and (3) eczema. It typically manifests in boys within the first few months of life as petechiae and recurrent infections (e.g., diarrhea). It is caused by numerous distinct mutations in a gene on the X chromosome that encodes a protein called WASP (Wiskott-Aldrich syndrome protein), which is expressed at high levels in lymphocytes and megakaryocytes. WASP binds members of the Rho family of GTPases. WASP itself controls the assembly of actin filaments that are required to form macrovesicles. X-linked agammaglobulinemia of Bruton (choice E) is not associated with thrombocytopenia and eczema. Choices A, B, and C are not X-linked genetic diseases.Diagnosis: Wiskott-Aldrich syndrome