IgA-, IgM- and IgG2-IgG3-IgG4 subclass deficiency (serum IgG, mg/dl [normal range]: 940 [790–1700]; serum IgG2, mg/dl [normal range]: 51 [150–600]; serum IgG3, mg/dl [normal range]: 5 [20–100]; serum IgG4, mg/dl [normal range]: <7 [8–120]; serum IgA, mg/dl [normal range]: <6 [76–450]; serum IgM, mg/dl [normal range]:29 [90–350]) with normal levels of IgG1 (data not shown) and antibody deficiency against bacterial polysaccharides was diagnosed. This evidence concerns the gene CD79A and agammaglobulinemia.