Chapter 453 Hereditary Elliptocytosis
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
