Hereditary Hemolytic Spherocytosis in the Active-Duty Population: A Unique Case.

Hereditary spherocytosis (HS) is a common inherited cause of hemolytic anemia and is most often diagnosed in childhood. While the condition does not by itself disqualify affected adults from military service, its autosomal dominant inheritance has important implications for offspring, who may develop more severe disease. We report the case of a 38-year-old active-duty US Army soldier of Saipanese (Chamorro) descent who presented with persistent, unexplained fatigue -- most pronounced during strenuous physical activity -- despite adequate sleep. He had no formal family history of anemia, although one of his three children carries an undiagnosed anemia. Physical examination revealed splenomegaly. Laboratory evaluation demonstrated compensated hemolysis, as evidenced by a low-normal hemoglobin maintained by a reticulocyte response of 9.36%, a normal mean corpuscular volume, an elevated mean corpuscular hemoglobin concentration of 36.7 g/dL -- a characteristic diagnostic feature of HS -- an elevated red cell distribution width, undetectable haptoglobin, and elevated lactate dehydrogenase and indirect bilirubin. The peripheral blood smear was reported by the staff pathologist as a normocytic, normochromic anemia with occasional spherocyte-like forms and mild polychromasia. The patient also demonstrated mild-to-moderate hepatic iron overload despite the absence of transfusions. Genetic testing identified a heterozygous nonsense mutation in the