Familial isolated congenital asplenia: a rare, frequently hereditary dominant condition, often detected too late as a cause of overwhelming pneumococcal sepsis. Report of a new case and review of 31 others.

UNLABELLED: Congenital isolated asplenia may arise as a minor form of situs abnormalities or result from an unrelated specific defect of spleen development. It is a rare life-threatening condition and pneumococcal sepsis is often the first sign of the disease. We report on the case of a deceased 11-month-old girl and her father who developed recurrent pneumococcal meningitis. The fatal evolution in the girl was due to Streptococcus pneumoniae serotype 23 with intermediate penicillin sensitivity 4 h after amoxicillin (100 mg/kg i.v.) administration. Establishing the diagnosis of congenital isolated asplenia in the case of pneumococcal sepsis can be achieved by performing two easy and non-invasive investigations: searching for Howell-Jolly bodies on blood smears and performing ultrasound examination of the abdomen to look for the spleen. In the case of congenital isolated asplenia, use of appropriate prophylaxis could save the lives of affected children. Our review of the literature yielded 31 cases of congenital isolated asplenia. Thirteen were sporadic and 18 were familial cases involving eight families. CONCLUSION: in the case of Streptococcus pneumoniae sepsis, a systematic search for Howell-Jolly bodies on blood smears and ultrasound examination of the abdomen for the presence of asplenia should be mandatory to detect isolated congenital asplenia. If asplenia is found, potentially life-saving antibiotic prophylaxis and pneumococcal vaccination should be initiated.