| A rare non-syndromic potentially life-threatening visceral malformation with the absence of normal spleen function, resulting in a primary immunodeficiency. Typically, the condition manifests with severe, recurrent, overwhelming infections (especially pneumococcal sepsis) in otherwise apparently healthy infants. In adults with no history of severe sepsis in infancy, thrombocytosis may be the presenting sign. Howell-Jolly bodies on blood smears and an absent spleen on abdominal ultrasound examination are highly suggestive associated findings. There is evidence this disorder is caused by heterozygous mutation in the RPSA gene on chromosome 3p21. |
