Hereditary Elliptocytosis

Chapter 453 Hereditary Elliptocytosis




Hereditary elliptocytosis is a less common disorder than spherocytosis and also varies markedly in severity. Mild hereditary elliptocytosis produces no symptoms; more severe varieties can result in neonatal poikilocytosis (shape variation) and hemolysis, chronic or sporadic hemolytic anemia, or hereditary pyropoikilocytosis (HPP), which is a severe disorder with microspherocytosis and poikilocytosis. Hereditary elliptocytosis is rare in Western populations and is more common among West Africans.



Etiology


Hereditary elliptocytosis is inherited as a dominant disorder. In the rare instances when 2 abnormal alleles are inherited (HPP), the patient exhibits particularly severe hemolytic anemia. Various molecular defects have been described in hereditary elliptocytosis; these produce abnormalities of α- and β-spectrin and defective spectrin heterodimer self-association (see Fig. 452-1). The abnormalities (spectrin mutations) can provide resistance to malarial infection. Such defects in horizontal protein interactions result in gross membrane fragmentation, particularly in homozygous HPP. Less commonly, mutations in protein 4.1 and glycophorin C can produce elliptocytosis.



Clinical Manifestations


Elliptocytosis may be an incidental finding on a blood film examination and might not be associated with clinically significant hemolysis (see Fig. 452-4B). The diagnosis of hereditary elliptocytosis is established by the findings on the blood film, the autosomal dominant inheritance pattern, and the absence of other causes of elliptocytosis, such as deficiencies of iron, folic acid, or vitamin B12

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Jun 18, 2016 | Posted by in PEDIATRICS | Comments Off on Hereditary Elliptocytosis

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