Anemia Due to Unexpected Zinc-Induced Copper Deficiency

Anemia due to acquired copper deficiency is most commonly the result of malabsorption or dietary deficiency. However, it can occasionally be due to excess zinc intake, which impairs the absorption of copper. Copper deficiency may result in vacuolated erythroid and myeloid precursors in the bone marrow, and sometimes features resembling myelodysplasia that, although not specific, may be an important clue to the diagnosis. Background and Clinical Significance: We report bone marrow findings in a child with anemia due to zinc-induced copper deficiency. Case Presentation: An 18-year-old female with cerebral palsy admitted for respiratory failure was found to have anemia and leukopenia with absolute neutropenia. A bone marrow smear showed occasional ring sideroblasts. Additional testing revealed reduced serum copper and elevated serum zinc. Further inquiry uncovered a several-year history of high-dose zinc supplementation. Conclusions: It is important to consider copper deficiency as a potential etiology in patients with anemia and neutropenia, as it may otherwise be mistaken for vitamin B12 deficiency or myelodysplasia. The presence of small vacuoles in hematopoietic precursors is an important clue to the diagnosis and may help avoid ineffective interventions.