At age 15, in the context of an admission for pulmonary tuberculosis, he was evaluated by clinical immunology, and found to have hypogammaglobulinemia (IgM: 9, IgG: 430 and IgA:16 mg/dL), absent anti-HB S Ag, rubella, or mumps IgG response (despite prior vaccination) and preserved B cells 3,2% of leukocytes. The gene discussed is GSTM1; the disease is agammaglobulinemia.