Hereditary splenic hypoplasia

The hazard of overwhelming infection following splenectomy has been the subject of controversy and the physiologic role of the spleen in childhood remains unclear. We studied five siblings who are the offspring of a consanguineous marriage. One of two boys and two of three girls had severe hypoplasia of the spleen, presumably on an hereditary basis, and no other anatomic abnormality. Immunologic competence in the affected children was intact, except for their inability to form antibody to intravenously injected sheep red cells. One child died of overwhelming Haemophilus influenzae sepsis and the other two had repeated episodes of pneumococcal meningitis and H. influenzae sepsis. This isolated, presumably hereditary, abnormality may help define the spleen's role in resistance to infection.