HY USMLE Q #967 – Hematology

A 10-year-old girl is brought to the physician for a follow-up examination. Vitals are normal. Physical examination shows scleral icterus. Her father has a history of cholecystectomy and splenectomy as a teenager. Laboratory studies show:

Hemoglobin                                                                                                                 9 g/dL
Mean corpuscular volume                                                                                   85 fL
Red cell distribution width                                                                                  13% (NR12-16)
Platelets                                                                                                                         300,000/μL
WBCs                                                                                                                               8,000/μL

Which of the following is the most likely explanation for these findings?

  Deficiency of erythrocyte spectrin
  Glutamic acid to lysine substitution
  Glutamic acid to valine substitution
  Reduced production of alpha-globin
  Reduced production of beta-globin