What causes thalassemia?

Thalassemia is caused by variant or missing genes that affect how the body makes hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen. People with thalassemia make less hemoglobin and fewer circulating red blood cells than normal. The result is mild or severe anemia.

Many possible combinations of variant genes cause the various types of thalassemia. Thalassemia is always inherited (passed from parents to children). People with moderate to severe forms of thalassemia received variant genes from both parents. A person who inherits a thalassemia gene or genes from one parent and normal genes from the other parent is a carrier (thalassemia trait). Carriers often have no signs of illness other than mild anemia, but 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. If the problem is with the alpha globin part of hemoglobin, the disorder is alpha thalassemia. If the problem is with the beta globin part, it is called beta thalassemia. There are both mild and severe forms of alpha and beta thalassemia. Severe beta thalassemia is often called Cooleys anemia

What is "Thalassemia?

Thalassemia (American English) (or Thalassaemia in British English) is an inherited disease of the red blood cells, classified as a hemoglobinopathy (a disorder of red blood cells). In other words, Thalassemia is a genetically acquired blood disorder. The genetic defect results in synthesis of an abnormal hemoglobin molecule. The blood cells are vulnerable to mechanical injury and die easily. To survive, many people with thalassaemia need blood transfusions at regular intervals.


Thalassemia, the disorder is named after the Greek word “thalassa” (sea) because it was originally observed in persons of mediterranean descent. It is also known as Cooley’s Anemia or Mediterranean Anemia.


Thalassemia developed as a natural mutation of the blood as a means of natural resistance to malaria. Although it was originally more common in the malaria zones of the planet, it is estimated that over 60 million people are carriers of Thalassemia, more than 2 million in the alone. It is found in very many countries, far away from malaria zones.


It comes in two forms: alpha and beta, alpha being more severe. In alpha thalassemia, inheritance of two copies of the gene results in death of the fetus. In beta thalassemia, inheritance of both copies of the gene results in thalassemia major which requires lifelong blood transfusions and iron chelation treatment. If left untreated, thalassemia major is fatal within the first few years of a child.


Inheritance of just one copy of the gene, dubbed thalassemia minor can widely vary from asymptomatic to a moderate anemia, and can significantly impact quality of life, especially in coexistance with other diseases. A milder form of the disease can occur with two inherited copies of the gene known as thalassemia intermedia, which requires less frequent treatments. Additional complications can occur if one inherits other hemoglobin disorder traits such as sickle cell or hemochromatosis.


Thalassemia is not very well known or very effectively screened and treated in most of the countries. As a result, many patients are misdiagnosed or improperly treated. Other than genetic testing, thalassemia is typically diagnosed with a hemoglobin electrophoresis test. Thalassemia major patients are severely anemic and require regular blood transfusions all throughout their lives, and daily iron chelation treatments to remove excess iron from the body from the blood transfusions. Thalassemia intermedia patients require similar but less frequent treatment. Major complications include spleen enlargement, gall bladder stones, bone deformation, developmental disorders and death. With proper treatment, it is now possible for a thalassemia major patient to live well past their forties.


Thalassemia minor can be asymptomatic or it can range from mild to moderate anemia which varies with age, and other health factors such as nutrition, diet and other disorders. It can also co-exist with B12 (folic acid) deficiency, and/or iron deficiency and may require periodic treatment. Thalassemia minor patients can have lower stamina, increased fatigue and lethargy because thalassemia results in smaller red blood cells that can carry less oxygen. Since thalassemia minor patients don’t receive blood transfusions, if they are moderately anemic they may need to alter their lifestyle.


Thalassemia major and intermedia patients also suffer fatigue, decreased stamina and lethargy, especially right before a transfusion. They require an iron-free diet for life and many lifestyle adjustments.