Common variable immunodeficiency is a heterogeneous group of disorders with arthritis and/or arthralgia as its most commonly associated autoimmune manifestation. We report 2 cases of common variable immunodeficiency in siblings who also had other unusual signs and symptoms. A 10-year-old boy suffered from bradycardia, hypothermia, hypoglycemia, and chronic eczema. His 13-year-old sister suffered from Kikuchi lymphadenitis, hypoperfusion and atrophy of the left cerebral hemisphere, and hemiparesis. They both showed classical laboratory findings of common variable immunodeficiency and the boy's associated symptoms responded to intravenous immunoglobulin therapy. The findings from these cases suggest that a defect in the neuro-endocrine-immune axis may be one of the genetic bases of common variable immunodeficiency.