Thalassemia is an inherited disorder that affects the production of hemoglobin and causes anemia. Hemoglobin is the substance in red blood cells that enables them to transport oxygen throughout the body. It is composed of a heme molecule and protein molecules called globins. Owing to an inherited genetic trait, lower-than-normal amounts of globins are manufactured in the bone marrow. If the trait is inherited from both parents, a globin may be entirely absent. Thalassemia causes varying degrees of anemia, which can range from insignificant to life threatening. The resulting anemia triggers a surge in red blood cell production, but the new cells are also defective. The bone marrow expands as it attempts to keep pace with the perceived need for new red blood cells, setting the stage for bone deformity and pain. Jaundice, indicated by yellowed skin, can result from high levels of bilirubin (the end product of...