The most frequently identified genetic alteration in our cohort was the TACI mutation, followed by mutations in DOCK8, RAG1, LRBA, PRF1, PSTPIP1, CECR1, PRKDC, and MRTFA. TACI mutations are widely recognized as key contributors to immune dysregulation in IEIs, particularly in CVID. The gene discussed is TNFRSF13B; the disease is common variable immunodeficiency.