Thalassemia is a hereditary condition that affects the blood and results in an abnormal form of haemoglobin, a protein molecule present in red blood cells (RBCs) that carries oxygen. This disorder leads to the destruction of RBCs and can result in anaemia, ranging from a mild illness with no symptoms to a serious or life-threatening disease. Fortunately, modern treatment offers a good outlook for severe cases of thalassemia, but it requires long-term care and treatment to prevent complications. Thalassemia is most common among people with Mediterranean or Asian family backgrounds.

Causes of Thalassemia

The origin of a substantial chemical called haemoglobin is an inherited (genetic) change affecting the genes. Haemoglobin is an oxygen-containing molecule found in red blood cells and is responsible for the red colour of blood.

Haemoglobin is composed of various components, with the key components being alpha and beta chains. These two components are placed together to form the haemoglobin molecule, however in thalassemia, part of the haemoglobin is flawed, usually either the alpha or beta chain. This means that the haemoglobin isn’t functioning properly, leading to a lack of natural haemoglobin and red blood cells that break down easily. This results in anaemia, which has a variety of symptoms.

In the meantime, the body is trying to produce more haemoglobin and red blood cells, leading to a process of overproduction which may cause further symptoms and complications. The volume of irregular haemoglobin varies depending on the type of thalassemia, ranging from a large proportion to a small one. This is essentially what defines the extent of thalassemia, although certain factors may also be involved. Thus, two people with the same type of thalassemia may have different levels of severity from the same disorder.

The two main forms of thalassemia are called thalassemia alpha and thalassemia beta, while other rarer forms also exist.

Beta Thalassemia

Beta thalassemia is an inherited blood disorder characterized by decreased levels of functional haemoglobin. Haemoglobin, which is present in red blood cells (RBCs), is a red pigment rich in iron, and is responsible for carrying oxygen throughout the body. Beta thalassemia can manifest in three forms - mild, intermediate, and severe, depending on the severity of the disorder. Those with beta-thalassemia minor often have no symptoms and are unaware of the disorder.

Individuals with major and intermediate beta-thalassemia are treated with regular blood transfusions, which can lead to iron overload due to the excess iron levels in the body. This overload can cause a variety of other symptoms, however, it can be managed with medication. Beta-thalassemia is caused by mutations in the haemoglobin-beta (HBB) gene. Those with beta-thalassemia minor typically have a mutation in one HBB gene, whereas those with the major and intermediate forms have mutations in all HBB genes.

The signs of intermedia beta-thalassemia are highly variable, and severity falls in the wide range between the two extremes of the major and minor types. The main symptom of beta-thalassemia is anaemia, a condition caused by abnormally small (microcytic) red blood cells that are not formed in normal amounts and do not contain adequate functional haemoglobin. This leads to a lack of oxygen-rich blood (microcytic anaemia) throughout the body, resulting in classic signs of anaemia such as tiredness, weakness, shortness of breath, dizziness or headaches.

Beta thalassemia, also known as Cooley’s anaemia, is a severe form of beta-thalassemia. Infants who are affected usually show signs between the first two years of life, or as early as three to six months after birth. In developing countries, the full-blown version of beta-thalassemia major is more common. Fortunately, many people do not experience serious symptoms. Although beta-thalassemia major is a lifelong, chronic condition, people who adhere to the recommended treatments can lead healthy, fulfilling lives.

Beta thalassemia is a relatively rare disorder in the United States, but it is one of the most severe autosomal recessive disorders in the world. It is estimated that the prevalence of symptomatic cases in the general population is around 1 in 100,000 persons. However, the disease is more common in certain areas, such as the Middle East, Mediterranean, Africa, Central Asia, India, and the Far East. People who originate from these regions and live in other parts of the world are more likely to have beta-thalassemia.

Thalassemia Trait

Yes, it is possible to carry a gene for thalassemia and still make enough normal haemoglobin. Thalassemia usually does not cause any signs or problems, and unless you have a specific blood test, you may not know that you have it. However, understanding the diagnosis can be beneficial, as it:

Other forms of thalassemia can cause very mild anaemia, which is characterized by smaller and paler than average red blood cells (referred to as microcytic and hypochromic in laboratory reports). Iron deficiency can be mistaken for this form of anaemia.

Your kids can inherit the gene. However, if you and your mother have the same gene, your child may be given a double dose of an abnormal haemoglobin gene. To check the potential risk to the baby, parents or unborn children are usually scanned.

What is the Inheritance Pattern of Thalassemia?

There is a 1 in 4 chance that a child of two parents with beta-thalassaemia will have normal haemoglobin genes, a 1 in 2 chance that they will have beta-thalassaemia, and a 1 in 4 chance that they will have BTM or BTI.

Who Gets Thalassemia?

Anybody can carry a gene for thalassaemia. On average, there is a thalassaemia gene (and therefore has a thalassaemia trait) in 3 in 100 of the world population. Depending on the roots of your ancestors, the chance of having a thalassaemia gene varies. Thalassaemia is more prevalent in people of Mediterranean, Asian, or African descent.

How Is Thalassemia Diagnosed?

A blood test is used to diagnose a condition. The blood sample is then analyzed to determine the type of haemoglobin present. In certain cases, additional tests such as DNA (genetic) tests may be necessary to accurately diagnose the type of thalassaemia. These tests can also be used to test other family members when necessary.

Can Thalassemia Be Cured?

A stem cell transplant is an effective treatment, which involves either a transplant of bone marrow or a transplant of cord blood. These treatments take a donor’s normal blood cells and give them to the individual with thalassaemia, which can provide a life-long cure if the transplant is successful. However, a stem cell transplant is not suitable for everyone, as there are serious risks involved. Additionally, a good donor is necessary for the procedure to be successful.