Thalassemia: Causes, Symptoms, and Treatment

Content

In this article we will look at:

• What is thalassemia?
• How does thalassemia occur?
• Who is prone to thalassemia?
• What are the causes of thalassemia?
• What are the complications of thalassemia?
• What are the symptoms of thalassemia?
• How are different types of thalassemias diagnosed?
• What is the treatment for thalassemia?

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What is thalassemia?

Thalassemia is a group of inherited blood disorders, which inhibits the body's ability to produce haemoglobin and red blood cells.
A person with thalassemia will have too few red blood cells, low haemoglobin levels, and the red blood cells may be too small. The impact of this disorder can range from mild, to severe, to life-threatening.
Around 100,000 newborns are delivered each year with severe forms of thalassemia. It is most common in Mediterranean, South Asian, and African ancestry.

How does thalassemia occur?

The human body creates three types of blood cells:

• red blood cells
• white blood cells
• platelets  

Red blood cells contain haemoglobin, an iron-rich protein that distributes oxygen from the lungs to all parts of the body.
Apart from oxygen-haemoglobin also carries carbon dioxide from the body to the lungs, from where it is exhaled.

Hemoglobin contains two kinds of protein chains:

• alpha globin
• beta globin

If your protein chains are not normal in any way, or your body does not create enough of these protein chains then production of haemoglobin and red blood cells is affected, which in turn affects the distribution of oxygen in the body.

It is the genes which we inherit that controls how the body produces haemoglobin protein chains. Thalassemias can occur when these genes are abnormal or missing.

There are two primary forms of thalassemia:

• Alpha Thalassemia: thalassemia occurs if there are problems with some or all of the alpha-globin genes. Normally, each person has four genes for alpha globin. Alpha thalassemia occurs when one or more of the genes that control the making of alpha globins is absent or defective.
  There are four main types of Alpha Thalassemia disease:
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  • Alpha Thalassemia Major: which is a very serious disease in which severe anemia begins even before birth. Pregnant women carrying affected fetuses are themselves at risk for serious pregnancy and delivery complications.
  • Alpha Thalassemia Minor:  when children have two missing or mutated genes this condition is called alpha thalassemia minor. Children with this condition may have red blood cells that are smaller than normal and may also have slight anemia.
  • Hemoglobin H disease: If there are three missing or mutated genes it is called hemoglobin H disease. The symptoms can be moderate to severe.
  • Silent Alpha Thalassemia Carrier: If a child is missing one gene or has orne abnormal gene the child is a silent alpha thalassemia carrier. Silent alpha thalassemia carriers show no signs or symptoms of the disease, but can pass thalassemia on to their own children.
• Beta Thalassemia disease: Beta thalassemia occurs when there are problems with one or both of the beta-globin genes.This is the most common type of thalassemia. In Beta thalassemia, there is decreased production of normal adult haemoglobin (Hb A), which is the predominant type of haemoglobin in our bodies from birth to death.  In people with beta thalassemia, low levels of haemoglobin lead to a lack of oxygen in many parts of the body.Two genes are involved in making the beta haemoglobin chain. You get one from each of your parents. If you inherit:
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  • A single mutated gene: you have what is called thalassemia minor you'll have mild anemia, which is a slight lowering of the haemoglobin level in the blood. This situation can very closely resemble that with mild iron-deficiency anemia.
  • Two mutated genes: then you have what is called thalassemia major, or Cooley anemia. Babies with this condition usually have the symptoms of severe anemia in their first year of life. They do not possess the ability to produce normal, adult haemoglobin and constantly suffer from chronic fatigue. A milder form, called thalassemia intermedia, also may occur with two mutated genes.

Who is prone to thalassemia?

Factors that increase your risk of thalassemia include:

• Family history:  This condition is usually passed from parents to children through mutated haemoglobin genes.You are at an increased risk of having this condition if you have a family history of thalassemia.
• Certain regional ancestry: Thalassemia is observed to predominantly occur most often among African-Americans and in people of Mediterranean and Southeast Asian ancestry.

What are the causes of thalassemia?

The causes of thalassemia are:

• inheriting abnormal and mutated genes involved in haemoglobin production from your parents
• if one of your parents is a carrier for thalassemia, you may become a carrier of the disease yourself, though you will not have any symptoms. You may also develop what is called thalassemia minor in which case you may develop minor symptoms.

What are the complications of thalassemia?

Possible complications of thalassemia include:

• Excessive Iron: People with thalassemia can get too much iron in their bodies, either from the disease or from frequent blood transfusions.
• Susceptibility to Infections: People with thalassemia have an increased risk of infection.

In cases of severe thalassemia, the following complications can occur:

• Complications of heart: such as congestive heart failure and abnormal heart rhythms (arrhythmias)
• Enlarged spleen: since thalassemia causes the destruction of a large number of red blood cells which in turn causes your spleen to enlarge and work harder than normal.
• Bone deformities: since thalassemia can make your bone marrow expand
• Slow growth rate:  of a child and delayed puberty.

What are the symptoms of thalassemia? How are thalassemias diagnosed?

The symptoms of thalassemia can vary. Some of the most common ones include:

• bone deformities, especially in the face
• dark urine
• delayed growth and development
• excessive tiredness and fatigue
• yellow or pale skin

Diagnosis

Thalassemias are diagnosed using blood tests. If you notice any symptoms you can first visit your family physician or a general physician who in turn will refer you to a haematologist based your condition.

The haematologist will suggest special haemoglobin tests to diagnose your condition:

• CBC shows the amount of red blood cells and haemoglobin in the blood.
  People who have thalassemias have fewer healthy red blood cells and less haemoglobin than normal in their blood.
• A haemoglobin test reveals the problems with the alpha or beta globin protein chains present within the haemoglobin.

What is the treatment for thalassemia?

The treatment of thalassemias depends on the severity of the particular type of thalassemia.

The treatments can include:

• Blood transfusions
• Iron chelation therapy which is used to prevent iron overload in the body due to regular blood transfusions
• Folic acid supplements helps build healthy red blood cells.
• Blood and marrow stem cell transplant which replaces faulty stem cells in the person suffering from thalassemia, with healthy ones taken from a donor. Stem cells are cells within the bone marrow that help in producing red blood cells and other types of cells.