A 7-Month-Old Boy Is Evaluated in the Clinic for Recurrent

Multiple Choice

A 7-month-old boy is evaluated in the clinic for recurrent bacterial infections.His tonsils are not visible on physical examination.Serum immunoglobulin A (IgA) and IgG levels are markedly decreased,and serum IgM levels are slightly below normal.Based on the findings described,which one of the following should be excluded from the differential diagnosis?

A) X-linked agammaglobulinemia
B) X-linked severe combined immunodeficiency disease (X-linked SCID)
C) Common variable immunodeficiency
D) X-linked hyper-IgM syndrome
E) Adenosine deaminase deficiency (ADA)