Thalessemia trait is one of those anemias. In the group of anemias called the thalessemias, inadequate amounts of hemoglobin are produced. These anemias are all caused by gene mutations, and are therefore inherited. As is true of the other major type of inherited anemia, sickle cell anemia, the different thalessemias are more common in certain population groups. Hemoglobin is composed of two parts, a heme portion which carries the iron molecule necessary for the hemoglobin to carry oxygen, and a globin part which forms the framework holding the heme.
Normal globin is made up of two chains, designated alpha and beta.
There are two alpha and two beta chains in each hemoglobin molecule. In the thalessemias, the inherited mutations result in less than the normal two chains of each type being produced. Two separate genes are required to produce each alpha chain. Mutations affecting the alpha chains are commonly seen in African-Americans, about 30 percent carry a mutation in one of the alpha chain genes. This does not produce anemia, and the person will never become ill from it.