In the majority of cases, HS is inherited in an autosomal dominant form, but may be inherited in an autosomal recessive form or occur as a result of new gene mutations.
HS is divided into four types of presentations (mild, moderate, moderate / severe, and severe form), differentiated by severity of symptoms. The majority of patients present with the moderate or mild form. Patients with the mild form may have very mild anemia or present without symptoms. Patients with the moderate form usually present with anemia, jaundice, and splenomegaly, and may develop gallstones. Signs and symptoms of moderate HS are usually apparent in childhood. Patients presenting with the moderate / severe manifestation possess the same features of the moderate form but also have severe anemia. Patients presenting with the severe form have a life-threatening manifestation requiring frequent blood transfusions. In addition to severe anemia, splenomegaly, jaundice and increased risk for gallstones, patients with severe HS may also have short stature, skeletal deformities, and delayed sexual development.
Common complications include bilirubin gallstones and obstructive jaundice. Less common complications include leg ulcers, extramedullary hematopoietic tumors, priapism, spinocerebellar degenerative syndromes, hypertrophic cardiomyopathy, and movement disorder with myopathy.
Typical laboratory features include mild or moderate anemia, reticulocytosis, increased mean corpuscular hemoglobin concentration, spherocytes on peripheral blood smear, and abnormal incubated osmotic fragility test. Treatment includes mostly supportive care with folic acid supplementation, blood transfusion and erythropoietin, and hematopoietic cell transplantation. Splenectomy is definitive treatment in patients who are candidates.
D58.0 – Hereditary spherocytosis
55995005 – Hereditary spherocytosis