Causes of Thalassemia
Thalassemia is directly linked to genetics and how the genes that affect hemoglobin production are inherited. People with moderate to severe forms received variant genes from both parents. People who are carriers of the disease received variant genes from one parent and normal genes from the other parent. Regardless of the causes of thalassemia, treatment options are available for all forms of the disease.
Thalassemia occurs when there are variant or missing genes that affect how the body makes hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen to other parts of the body. People who have thalassemia make less hemoglobin and have fewer circulating red blood cells than normal, which results in mild or severe anemia.
There are many possible combinations of variant genes that cause the various types of thalassemia. Thalassemia is always inherited (passed from parents to children). People with moderate to severe forms received variant genes from both parents. People with thalassemia trait (carriers) received variant genes from one parent and normal genes from the other parent.
Although carriers often have no signs of illness other than mild anemia, they can pass the variant genes on to their children.
Hemoglobin includes two kinds of protein chains called alpha-globin chains and beta-globin chains. Alpha thalassemia occurs when there is a problem with the alpha-globin part of hemoglobin. Beta thalassemia occurs when there is a problem with the beta-globin part of hemoglobin. There are both mild and severe forms of alpha and beta thalassemia. Severe beta thalassemia is often called Cooley's anemia.