The patient is exhibiting signs of hyperhemolytic crisis, which results in worsening anemia (Hgb 7.2 mg/dL) despite adequate reticulocyte production (reticulocyte 4.2%). It is often caused by a G6PD-deficiency, which is indicated by a positive fluorescent spot test. It is found in up to 20% of descendants from Africa; sickle cell disease is found almost exclusively in patients of African descent in America. Spherocytes on a peripheral blood smear test indicates an anemia other than SCD such as autoimmune hemolytic anemia, which is unlikely and therefore surprising.