Thalassemia : Understanding the disease

Thalassemia is an inherited blood disorder that reduces the production of functional hemoglobin (the protein in red blood cells that carries oxygen). This causes a shortage of red blood cells and low levels of oxygen in the bloodstream, leading to a variety of health problems. There are two main types of thalassemia: alpha thalassemia and beta thalassemia.  
Beta thalassemia is caused by mutations in the HBB gene while alpha thalassemia is caused by mutations in the HBA1 and/or HBA2 genes. Both are inherited in an autosomal recessive manner. which means that two copies of the gene are necessary to produce the condition, one inherited from each parents. Treatment depends on the type and severity of the condition but may include blood transfusions and/or folic acid supplements. In people with beta thalassemia, low levels of hemoglobin lead to a lack of oxygen in many parts of the body. Affected individuals also have a shortage of red blood cells (anemia), which can cause pale skin, weakness, fatigue, and more serious complications. People with beta thalassemia are at an increased risk of developing abnormal blood clots.

While two genes are involved in making the beta hemoglobin chain. If you inherit:

  • One mutated gene, you’ll have mild signs and symptoms. This condition is called beta-thalassemia minor or referred to as a beta-thalassemia trait.
  • Two mutated genes, your signs and symptoms will be moderate to severe. This condition is called beta-thalassemia major, which is also known as Cooley’s anemia. Babies born with two defective beta hemoglobin genes usually are healthy at birth, but develop signs and symptoms within the first two years of life. A milder form, called beta-thalassemia intermedia, also may occur with two mutated genes.