Nokea
A newborn infant develops jaundice on day of life 2. Labs are drawn, and she has a hemoglobin of 7.4 g/dL with a reticulocyte count of 8%. Upon peripheral blood smear review, she is found to have bizarre red cell forms with significant polkilocytosis. Although her parents have normal blood counts, on review of their peripheral blood smears, they both have a moderate number of ovalocytes. Which of the following is the most likely cause of the infant's red cell findings?
Correct Answer: C
Rationale: The correct answer is C because the infant's red cell findings of ovalocytes and polikilocytosis are consistent with hereditary elliptocytosis, which is caused by mutations in genes encoding spectrin. In this scenario, the inheritance pattern aligns with the infant receiving an alpha-spectrin mutation from both parents, leading to the observed erythrocyte abnormalities. This condition may improve over time due to compensatory mechanisms.
Choice A (autosomal dominant ankyrin mutation causing hereditary spherocytosis) is incorrect because the clinical presentation and red cell morphology do not support a diagnosis of hereditary spherocytosis.
Choice B (inherited band 3 variants and need for splenectomy) is incorrect as the infant's condition does not match the characteristics of hereditary spherocytosis requiring splenectomy.
Choice D (PKLR variant and pyruvate kinase deficiency) is incorrect as the infant's red cell morphology is not indicative