Thalassemia

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An overview of the causes, symptoms and treatment of this blood disorder caused by a defect in the gene that controls the production of hemoglobin.

Key points

Thalassemia is a blood disorder caused by a defect in the gene that controls the production of hemoglobin.
It is an inherited form of anemia that most commonly affects children of Mediterranean, African and Asian descent.
Children with thalassemia major may look pale and have shortness of breath.
Thalassemia major is treated by monthly blood transfusions.

Introduction

What is thalassemia?

Thalassemia is a group of blood diseases caused by production of abnormal hemoglobin. Hemoglobin is a protein found in red blood cells that carries oxygen to the body. Thalassemia is an inherited form of anemia. It most commonly affects children of Mediterranean, African and Asian descent. There are many different forms of thalassemia and the degree of severity ranges from no symptoms at all to fatal disease. If you have thalassemia minor (trait), you are a carrier of the disease and your red blood cells are smaller than normal, but you are healthy. Thalassemia major can be fatal. People with alpha thalassemia major die in infancy. People with beta thalassemia major require regular blood transfusions. There are other forms of thalassemia which are not as severe.

Signs and symptoms

Signs and symptoms of thalassemia

Children with thalassemia major may show signs and symptoms in early infancy. The symptoms are similar to children with anemia:

pale skin
fatigue
weakness
shortness of breath

Other symptoms may include:

irritability
yellow discolouration of skin (jaundice)
slow growth
protruding abdomen
facial bone deformities
dark urine

Causes, risk factors and prevalence

Causes

The blood disorder is caused by a defect in the gene that controls the production of hemoglobin. The defective gene causes an inability to produce normal hemoglobin. Children inherit this gene from one or both parents. If a child inherits the faulty gene from both parents, the child will have thalassemia major. If the faulty gene is only passed on by one parent, the child has thalassemia minor. The child then becomes a carrier of the defective gene.

Chromosome distribution chart for a male and a female both carrying the beta thalassemia gene in one chromosome — In this example, both parents are carriers of beta thalassemia. They may have mild anemia. Their children may inherit one, two, or no copies of the beta thalassemia gene. If a baby inherits one copy of the gene, she will have thalassemia trait like her parents. If a baby inherits two copies, she will have beta thalassemia (moderate to severe anemia).

Treatment

What a doctor can do to help your child with thalassemia

Your child's doctor will take into consideration the signs and symptoms you have observed. A diagnosis can only be confirmed by blood tests. Thalassemia minor does not require treatment. Thalassemia major is treated by monthly blood transfusions. Recurrent blood transfusions cause an overload of iron in your child's body. This can lead to heart or liver damage. Such damage can be prevented by medicine to remove the excess iron.

Prevention

People with any form of thalassemia should get genetic counseling. Prenatal tests are also available.

Complications

A child with this blood disorder may have gallstones. Other children may have poor growth. Heart failure and infection are the leading causes of death among children when the disorder is left untreated. With treatment, the major complications are related to iron overload.

When to seek medical attention

When to seek medical assistance

If your child shows symptoms of anemia, visit your child's doctor as soon as possible. If you have a family history of thalassemia, you should be tested to see if you are a carrier.

Last updated: May 7th 2010