Which statement best describes hereditary spherocytosis?

Which statement best describes hereditary spherocytosis?

• A. Autosomal recessive; RBC membrane enzyme deficiency.
• B. Autosomal dominant; RBC membrane defect (spectrin) leading to increased fragility and sphere-shaped RBCs, with splenic destruction.
• C. X-linked recessive.
• D. Mitochondrial inheritance.

Answer: (B)

Hereditary spherocytosis results from defects in red blood cell membrane–skeleton proteins (most often spectrin or associated proteins), which weaken the membrane and cause loss of membrane surface area relative to volume. The cells become sphere-shaped and less deformable, so they’re trapped and destroyed by splenic macrophages, leading to extravascular hemolysis. This condition is most commonly inherited in an autosomal dominant pattern, with a spectrin-related membrane defect producing the characteristic sphere-shaped, fragile RBCs. The statement that best describes it notes the autosomal dominant inheritance, a membrane defect involving spectrin, the resulting spherical red cells, and increased fragility with splenic destruction. Other choices misstate the inheritance pattern or underlying defect (enzyme deficiencies, X-linked or mitochondrial inheritance), which do not fit hereditary spherocytosis.

Hereditary spherocytosis results from defects in red blood cell membrane–skeleton proteins (most often spectrin or associated proteins), which weaken the membrane and cause loss of membrane surface area relative to volume. The cells become sphere-shaped and less deformable, so they’re trapped and destroyed by splenic macrophages, leading to extravascular hemolysis. This condition is most commonly inherited in an autosomal dominant pattern, with a spectrin-related membrane defect producing the characteristic sphere-shaped, fragile RBCs. The statement that best describes it notes the autosomal dominant inheritance, a membrane defect involving spectrin, the resulting spherical red cells, and increased fragility with splenic destruction. Other choices misstate the inheritance pattern or underlying defect (enzyme deficiencies, X-linked or mitochondrial inheritance), which do not fit hereditary spherocytosis.