Spectrin tetramer-dimer equilibrium in hereditary elliptocytosis
T Coetzer and S Zail
The proportion of spectrin tetramers and dimers in 4 degrees C low ionic
strength extracts of red cell membranes of 9 subjects with 4 different
variants of hereditary elliptocytosis (HE) and 2 subjects with hereditary
spherocytosis (HS) was determined by nondenaturing gel electrophoresis.
Such extracts reflect the native oligomeric state of spectrin in the red
cell membrane. In two hemolytic HE variants (an unclassified adult with
increased thermal sensitivity of red cells and an infant also showing
increased thermal sensitivity of red cells), the proportion of dimers was
increased, whereas the remaining subjects had values within the control
range. Conversion of spectrin tetramers to dimers under isotonic conditions
at 37 degrees C, or spectrin dimers to tetramers at 30 degrees C, resulted
in a high proportion of dimers in the above two HE variants, as well as in
a third variant with probable mild HE and sporadic hemolysis. The mother of
the infant with elliptocytosis and increased thermal sensitivity of red
cells, although hematologically normal, had an increased proportion of
dimers in 4 degrees C low ionic strength extracts of her red cell
membranes. These findings reflect an underlying primary or secondary
abnormality of spectrin in these subjects that affects the association
state of spectrin in the red cell membrane. Their exact relationship to the
pathogenesis of the elliptical shape of the red cell, or to the presence of
hemolysis, is at present unclear.
Volume 59,
Issue 5,
pp. 900-905,
05/01/1982
Copyright © 1982 by The American Society of Hematology
