The laboratory test results revealed hypogammaglobulinemia (IgG, 85 mg/dL; IgA, 18 mg/dL; and IgM, 12 mg/dL); specific antibodies against hepatitis B virus, rubella, and varicella were undetectable despite previous vaccination (Supplementary Table 1). The gene discussed is CD79A; the disease is agammaglobulinemia.