Introduction: Common variable immune deficiency (CVID) is a heterogeneous disorder presenting with various clinical manifestations, including autoimmune cytopenias, lymphoproliferation, and granulomas. Heterozygous NFKB1 variants are considered the most common monogenic aetiologies of common variable immunodeficiency (CVID). (NF-? B)It is crucial in several biological processes, including adaptive immune response, proliferation, cell survival, and inflammation. Case: A 13-year-old previously well boy , 3rd born to nonconsanguineous healthy parents, presented with recurrent facial abscess, cervical lymphadenopathy , and was accidentally found to have pancytopenia in a full blood count. Later presented with buttock abscess, generalized lymphadenopathy & hepatosplenomegaly . He had pancytopenia without any abnormal cells in blood picture, and elevated inflammatory markers. His renal and liver functions were normal. HIV , virology panel, and Mantoux/ TB genexpert tests were negative. Chest X-ray normal, USS abdomen showed moderate hepatosplenomegaly with suspicious lymph nodes. Lymph node biopsy was reactive, bone marrow biopsy , trephine biopsy , immunoglobulin levels, Nitroblue Tetrazolium test were normal, and DAT - Positive. No abnormalities were picked in Upper and Lower GI endoscopies. Flow cytometry findings are suggestive of autoimmune lymphoproliferative syndrome. Genetics identified in the NFKB1 gene NM_003998.4 splice acceptor variant (CVID 12) Progress: Child responds to IVIG, steroids, & Immunosuppressive therapy Discussion: Clinical features are varied depending on the pathogenic variant in CVID.CVID12 is an autosomal dominant complex immunologic disorder with multisystem involvement & associated with autoimmunity . Diagnosis was aided by a basic immunologic panel & genetic testing. Management include regular IVIG, steroids & immunosuppression.