Question 4#

Which of the following proteins is not altered in hereditary spherocytosis (HS)?

A. Pyruvate kinase
B. Spectrin
C. Ankyrin
D. Band 3 protein

Correct Answer is A


The underlying abnormality in hereditary spherocytosis (HS) is an inherited dysfunction or deficiency in one of the erythrocyte membrane proteins (spectrin, ankyrin, band 3 protein, or protein 4.2), which results in destabilization of the membrane lipid bilayer. This destabilization allows a release oflipids from the membrane, causing a reduction in membrane surface area and a lack of deformability, leading to sequestration and destruction of the spherocytic erythrocytes in the spleen. Although less common than glucose-6-phosphate dehydrogenase (G6PD) deficiency overall, pyruvate kinase deficiency is the most common RBC enzyme deficiency to cause congenital chronic hemolytic anemia.