CD79A and Immunodeficiency: Among those with PID, the most frequent diagnosis was common variable immunodeficiency (CVID) (39.8%, n = 88), followed by IgG subclass deficiency (6.3%, n = 14), combined IgA and IgG subclass deficiency (5.9%, n = 13), and syndromic immunodeficiencies (5.4%, n = 12).