Family study of pediatric patients with primary antibody deficiencies.

Common variable immunodeficiency (CVID) and selective IgA deficiency (SIGAD) are the most common primary antibody deficiencies. These two diseases may have coincidence in one family and SIGAD can progress to CVID which suggest common underlying genetic defects between SIGAD and CVID. This study was designed to find the prevalence of multiple cases in families of Iranian patients with CVID or SIGAD.