THALASSEMIA

Thalassemia is a blood disorder passed down through families, in which the body produces abnormal form of hemoglobin.  Hemoglobin is the protein in the red blood cells that carries the oxygen throughout the body.  This is indicated in how ‘red’ a person’s red blood cells are.

People with the condition produce either no or too little haemoglobin, which is used by red blood cells to carry oxygen around the body, and in turn, causes the decrease in production of red blood cells in the body.  This can make them very anaemic (tired, short of breath and pale).

Causes of Thalassemia

Thalassemia is caused by mutations in the DNA of cells that make hemoglobin.  The mutations that cause thalassemia disrupt the normal production of hemoglobin and cause low hemoglobin levels and a high rate of red blood cell destruction, causing anemia. Hemoglobin is made of two proteins: Alpha globin and beta globin. Thalassemia occurs when there is a defect in a gene that helps control production of one of these proteins.

Types of Thalassemia

There are two main types of thalassemia:

  • Alpha thalassemia occurs when a gene or genes related to the alpha globin protein are missing or changed (mutated). This occur most often in persons from Southeast Asia, the Middle East, China, and in those of African descent.
  • Beta thalassemia occurs when similar gene defects affect production of the beta globin protein. This occur most often in persons of Mediterranean origin. To a lesser extent, Chinese, other Asians, and African Americans can be affected.

There are many forms of thalassemia. Each type has many different subtypes. Both alpha and beta thalassemia include the following two forms:

  • Thalassemia major. You must inherit the gene defect from both parents to develop thalassemia major.
  • Thalassemia minor.  Thalassemia minor occurs if you receive the faulty gene from only one parent. Persons with this form of the disorder are carriers of the disease. Most of the time, they do not have symptoms.

Risk factors for thalassemia include:

  • Asian, Chinese, Mediterranean, or African American ethnicity
  • Family history of the disorder

 

Symptoms of thalassaemia

Thalassemia symptoms include:

  • Fatigue
  • Weakness
  • Pale appearance
  • Yellow discoloration of skin (jaundice)
  • Facial bone deformities
  • Slow growth
  • Abdominal swelling
  • Dark urine

The signs and symptoms you experience depend on the type and severity of thalassemia you have. Some babies show signs and symptoms of thalassemia at birth, while others may develop signs or symptoms during the first two years of life. Some people who have only one affected hemoglobin gene don’t experience any thalassemia symptoms.

Diagnosing thalassaemia 

Your doctor will do a physical exam to look for an enlarged spleen.

A blood sample will be sent to a laboratory to be tested.

  • Red blood cells will appear small and abnormally shaped when looked at under a microscope.
  • A complete blood count (CBC) reveals anemia.
  • A test called hemoglobin electrophoresis shows the presence of an abnormal form of hemoglobin.
  • A test called mutational analysis can help detect alpha thalassemia.

Antenatal screening

Testing can be done before a baby is born to find out if it has thalassemia and determine how severe it may be. Tests used to diagnose thalassemia in fetuses include:

  • Chorionic villus sampling. This test is usually done around the 11th week of pregnancy and involves removing a tiny piece of the placenta for evaluation.
  • Amniocentesis. This test is usually done around the 16th week of pregnancy and involves taking a sample of the fluid that surrounds the fetus.

After birth

Unlike the related blood disorder sickle cell anaemia, newborn babies aren’t routinely screened for thalassaemia. There are two reasons for this:

  • blood tests are usually unreliable during the first six months of life
  • unlike sickle cell anaemia, thalassaemia doesn’t present an immediate threat to a baby’s life – babies born with sickle cell anaemia have a high risk of developing serious infections and need immediate treatment with antibiotics

If your baby starts to develop the symptoms of thalassaemia as they get older, a diagnosis can be confirmed using a blood test.

Assessing iron levels

If you have beta thalassaemia major, you’ll need regular blood transfusions, which will increase the level of iron in your body.

To remove the excess iron, a treatment known as chelation therapy will be used. This will prevent serious complications from excess iron occurring, such as heart or liver disease.

 

Treating thalassaemia 

Treatment for thalassemia depends on which type you have and how severe it is.

Treatments for mild thalassemia

Signs and symptoms are usually mild with thalassemia minor and little, if any, treatment is needed. Occasionally, you may need a blood transfusion, particularly after surgery, after having a baby or to help manage thalassemia complications.

Some people with beta-thalassemia intermedia may need treatment for iron overload. Although most people with this condition don’t need the blood transfusions that often cause iron overload, people with beta-thalassemia intermedia may have increased digestive absorption of iron, leading to an excess of iron. An oral medication called deferasirox (Exjade) can help remove the excess iron.

Treatments for moderate to severe thalassemia

Treatments for moderate to severe thalassemia may include:

  • Frequent blood transfusions. More-severe forms of thalassemia often require frequent blood transfusions, possibly every few weeks. Over time, blood transfusions cause a buildup of iron in your blood, which can damage your heart, liver and other organs. To help your body get rid of the extra iron, you may need to take medications that rid your body of extra iron.
  • Stem cell transplant. Also called a bone marrow transplant, a stem cell transplant may be used to treat severe thalassemia in select cases. Prior to a stem cell transplant, you receive very high doses of drugs or radiation to destroy your diseased bone marrow. Then you receive infusions of stem cells from a compatible donor. However, because these procedures have serious risks, including death, they’re generally reserved for people with the most severe disease who have a well-matched donor available — usually a sibling.

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