The ITK deficiency is associated with naive CD4+ T-cell lymphopenia, modest change in the number of CD4+ T-cells, impaired positive and negative selection of thymocytes due to reduced TCR signal levels, recurrent infections (for example, herpes virus infections), autoimmune cytopenias, lymphoproliferation, lymphadenopathy and hepatosplenomegaly. The gene discussed is CD4; the disease is Lymphadenopathy.