A homozygous variant of CD40LG (p.H125P) was also found in one patient.In addition, four genes related to CVID were screened: CTLA4 (p. P169A), NFKB1 (p. R533H), IL21R (c.867+10_867+28dup), and TNFRSF13B (p. R84T). The gene discussed is IL21R; the disease is common variable immunodeficiency.