Majority of DADA2 patients with PRCA/DBA-like clinical features have at least one of the following clinical features, such as, benign lymphoproliferation (lymphadenopathy and hepatosplenomegaly), low IgM/IgA/IgM, or reduced B/NK/CD4-T/CD8-T cells, with or without recurrent or unusual infections. The gene discussed is CD40LG; the disease is pure red-cell aplasia.