N Engl J Med 382 (13): 1219 - 1231, 2020. doi: 10.1056/NEJMoa1910182 Key Points Thalassemias result from decreased production of at least one globin polypeptide chain (beta, alpha, gamma, delta); the resultant abnormal red blood cells are microcytic, often abnormally shaped, and prone to hemolysis (causing anemia).