- Presence of sphere-shaped red blood cells in the blood. SYN: microspherocytosis. [spherocyte + G. -osis, condition]- hereditary s. [MIM*182900] a congenital defect of spectrin [MIM*182860], the main component of the erythrocyte cell membrane, which becomes abnormally permeable to sodium, resulting in thickened and almost spherical erythrocytes that are fragile and susceptible to spontaneous hemolysis, with decreased survival in the circulation; results in chronic anemia with reticulocytosis, episodes of mild jaundice due to hemolysis, and acute crises with gallstones, fever, and abdominal pain; symptomatology is highly variable; autosomal dominant inheritance, caused by mutation in the ankyrin gene (ANK1) on 8p. However, as with elliptocytosis, there is an autosomal recessive form [MIM*270970], caused by mutation in the alpha-spectrin 1 gene (SPTA1) on chromosome 1q. SYN: chronic acholuric jaundice, chronic familial icterus, chronic familial jaundice, congenital hemolytic icterus, congenital hemolytic jaundice, spherocytic anemia.
* * *sphe·ro·cy·to·sis .sfir-ō-sī-'tō-səs, .sfer- n the presence of spherocytes in the blood esp HEREDITARY SPHEROCYTOSIS
* * *n.the presence in the blood of abnormally shaped red cells (spherocyte). Spherocytosis may occur as a hereditary disorder (hereditary spherocytosis) or in certain haemolytic anaemia.
* * *sphe·ro·cy·to·sis (sfēr″o-si-toґsis) the presence of spherocytes in the blood; called also microspherocytosis.
Medical dictionary. 2011.