A 1-year-old boy is evaluated for a suspected immune deficiency.He has a history since birth of eczema,recurrent rashes,and diarrhea.His white blood cell count (WBC)count is 6.75/uL (normal values: 5.0-10.8 × 103 uL)with a normal differential.Platelet count is 35,000 (normal values: 150,000-350,000/uL),and the platelets are small.His IgG is 750 mg/dL (normal values: 600-1,500 mg/dL).IgM is 30 mg/dL (normal values; 75-150 mg/dL).IgA is 475 mg/dL (normal values: 50-125 mg/dL).IgE is 750 mg/dL (10-50 mg/dL).The boy's blood is typed as O-positive,and he does not have anti-A or anti-B antibodies.Flow cytometry performed on his blood shows 11% CD19 (normal values: 5%-20%)and 50% CD3 cells (normal values: 60%-80%)with a normal ratio of CD4:CD8.T-cell function tests are abnormal.This boy most likely has:

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Quizplus · Accepted Answer

The patient's characteristics and laboratory findings suggest Wiskott-Aldrich syndrome (WAS), an X-linked recessive disorder characterized by thrombocytopenia, eczema, recurrent infections, and immune dysregulation. The low platelet count and small platelet size are suggestive of WAS. The low IgM and elevated IgE and IgA levels are also common in WAS. The decreased number of CD19 cells and abnormal T-cell function tests further support the diagnosis of WAS. The patient's blood type and absence of anti-A and anti-B antibodies are not indicative of any specific immunodeficiency disorder. The other answer choices (Bruton's tyrosine kinase deficiency, DiGeorge anomaly, and ataxia telangiectasia) are not consistent with the patient's clinical and laboratory findings.

A 1-Year-Old Boy Is Evaluated for a Suspected Immune Deficiency