Which of the following is a typical finding in hereditary spherocytosis?

a. Increased mean cell hemoglobin concentration (MCHC)
b. Normal reticulocytes
c. Reduced fragility of red cells
d. Normal spectrin

ANS: A
It is common for the MCHC to be abnormally increased greater than 36 g/dL in patients with hereditary spherocytosis. This probably results from cellular dehydration of cells that have gone through the spleen and have low levels of water and potassium. The reticulocyte count is increased, osmotic fragility increased, and spectrin is abnormal.