A 52-year-old man is complaining of fatigue. His physical examination is normal, but his hemoglobin is low at 8.9 mg/dL. The reticulocyte count is 0.5 %, serum iron and TIBC are normal, and ferritin is elevated. A bone marrow aspirate reveals erythroid precursors that have accumulated abnormal amounts of mitochondrial iron.For the above patient with a hypochromic microcytic anemia, select the most likely diagnosis.