Review Question - QID 109111

A 24-year-old Turkish female presents to your office for a routine examination. She recently started a new job and has been tired most of the time. She does not have any dizziness and has not lost consciousness. She follows a well-balanced diet and is not vegetarian. She recalls that other family members have had similar symptoms in the past. On physical exam her temperature is 99°F (37.2°C), blood pressure is 115/78 mmHg, pulse is 100/min, respirations are 22/min, and pulse oximetry is 99% on room air. On physical exam, you notice conjunctival pallor. Labs are obtained and the results are shown below:

Hemoglobin: 10.2 g/dL
Hematocrit: 34%
Leukocyte count: 5,000 cells/mm^3 with normal differential
Platelet count: 252,000/mm^3
Mean corpuscular hemoglobin concentration: 20.4%
Mean corpuscular volume: 65 µm^3

Peripheral blood smear is shown in the image provided. The cause of her anemia is most likely associated with which of the following?