Mutations in TACI were also found in relatives of patients with CVID who suffered from IgA deficiency (IgAD) as well as in a patient with isolated IgAD.
Recently, patients with CVID and IGAD have been found to have mutations of the gene TNFRSF13B encoding the TACI (transmembrane activator and calcium-modulator and cyclophilin-ligand interactor), a member of the tumor necrosis factor-receptor superfamily.
Common variable immunodeficiency, CVID, is a primary antibody deficiency characterized by decreased levels of serum immunoglobulin G (IgG), decreased IgA and/or IgM and recurrent infections.