A 20-year-old African American woman presents to the emergen…
A 20-year-old African American woman presents to the emergency department with severe, sudden-onset chest pain and shortness of breath. She also reports generalized fatigue and joint pain. She has a known history of chronic anemia but has not followed up with a primary care provider in over a year. On exam, she is tachycardic, tachypneic, and has mild scleral icterus. Oxygen saturation is 91% on room air. Laboratory studies show: Hemoglobin: 7.9 g/dL (low), Reticulocyte count: 10.2% (high), MCV: 96 fL (normal), LDH: elevated, Indirect bilirubin: elevated, Haptoglobin: undetectable. What is the most likely diagnosis?