Hemoglobin is the red oxygen carrying pigment found in the blood’s red cells. It is made up of “heme” which carries iron and “globin” which is the protein part, made up of 4 long chains of amino acids (the building blocks of protein) - two chains are called “alpha” and the other two (depending on their structure) may be “beta”, “delta”, “gamma”, or “epsilon” depending on the type of hemoglobin. In older children and adults, hemoglobin is composed of 2 alpha chains and 2 beta chains. In Alpha thalassemia there is an abnormality in the production of alpha chains which causes the red cells to more easily breakdown. Learn more about Alpha Thalassemia.