An inherited abnormality of the red blood cell, caused by defects in structural membrane proteins. It is the most common form of inherited hemolytic anemia in the US and northern Europe. The severity of resultant hemolysis is related to the type and amount of membrane disruption.
May be diagnosed at any age. The key laboratory features are the presence of spherocytes on the blood smear in association with a negative direct antiglobulin test (DAT) and an elevated reticulocyte count.
May be newly diagnosed in children who present with severe anemia due to parvovirus infection. Patients may also be completely asymptomatic. In these cases, HS may be detected on a blood count/smear done for other reasons.
Management depends on the severity of the hemolysis and degree of anemia, but is generally supportive for most patients.
Splenectomy is the treatment of choice in patients with severe HS. This is best avoided until at least 6 years of age to reduce the risk of postsplenectomy sepsis.
Hereditary spherocytosis (HS) is an inherited abnormality of the red blood cell, caused by defects in structural membrane proteins. The condition is dominantly inherited in 75% of people. The severity of the disorder is related to the type and amount of membrane disruption, which is genetically determined. The abnormal cells are spherical. They are removed by the spleen, resulting in a reduced red-cell life span, deviating from the normal of 120 days by a variable degree. In severe cases, red-cell life span may be only 10 days. The severity of hemolysis varies between different individuals and can be exacerbated by infection. HS is associated with splenomegaly (commonly), anemia (variably) with an increased reticulocyte count, and jaundice (occasionally).
History and exam
Associate Professor of Pediatrics
University of Arkansas for Medical Sciences
SC is on an advisory board for HEMA Biologics for a hemophilia product (unrelated to this article).
Dr Shelley Crary would like to gratefully acknowledge Dr Paula Bolton-Maggs, a previous contributor to this topic. PB-M has received travel and accommodation payments to give a series of lectures on paediatric haematology, one of which was on HS. She also was an expert witness in a legal case concerning a child with HS. PB-M is an author of some references cited in this topic.
Professor of Medicine Emeritus
School of Medicine and Public Health
University of Wisconsin-Madison
RS is an author of a number of references cited in this monograph.
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