Autoimmune lymphoproliferative syndrome is a primary immunodeficiency caused by defective FAS-mediated apoptosis and usually accompanied by hypergammaglobulinemia. Yet some exceptions take place in the cohort of patients that complicated timely diagnosis, in particular, some symptoms may resemble common variable immune deficiency. In this article, we describe the patient with rare case of agammaglobulinemia and genetically confirmed autoimmune lymphoproliferative syndrome. The patient's parents agreed to use the information, including the child's photo, in scientific research and publications.