What is Thalassemia?
Thalassemia
Thalassaemia is the name for a group of inherited conditions that affect a substance in the blood called hemoglobin.
People with thalassaemia produce either no or too little hemoglobin, which is used by red blood cells to carry oxygen around the body.
This can make them very anemic (tired, short of breath and pale).
It mainly affects people of Mediterranean, south Asian, southeast Asian and Middle Eastern origin.
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There are different types of thalassaemia, which can be divided into alpha and beta thalassaemias. Beta thalassaemia major is the most severe type.
Other types include beta thalassaemia intermedia, alpha thalassaemia major and hemoglobin H disease.
It's also possible to be a "carrier" of thalassaemia, also known as having the thalassaemia trait.
Symptoms
Anaemia
Most people with thalassaemia major or other severe types will also be at risk of developing a range of health problems caused by a build-up of iron in the body. It's usually a side effect of repeated blood transfusions.
Too much iron in the body can cause:
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heart problems – including problems affecting the heart muscle (cardiomyopathy), an irregular heartbeat and heart failure
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swelling and scarring of the liver (cirrhosis)
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delayed puberty
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low levels of estrogen (in women) or testosterone (in men)
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diabetes
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problems with the thyroid gland (hypothyroidism) and parathyroid glands (hypoparathyroidism)
Lifelong treatment with medicine to stop iron building up to harmful levels will usually be needed. This is known as chelation therapy.
Too much iron in the body
Almost everyone with thalassaemia major or other serious types will develop anaemia, which can be life threatening in severe cases.
In anaemia there are low levels of haemoglobin, a substance that transports oxygen, in the blood.
It typically causes:
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tiredness and a general lack of energy
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shortness of breath
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pounding, fluttering or irregular heartbeats (palpitations)
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pale skin
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yellowing of the skin and eyes (jaundice)
Frequent blood transfusions are usually needed for life to stop anaemia becoming severe.
How Is It Diagnosed?
Testing after birth or later in life
Newborn babies are not routinely tested for thalassaemia because the test used is not always reliable soon after birth and thalassaemia is not immediately dangerous.
But the main type, beta thalassaemia major, is often picked up as part of the newborn blood spot test (heel prick).
A blood test can be carried out at any point to diagnose thalassaemia if a child or adult has symptoms of thalassaemia and the condition was not picked up earlier on.
Testing for the thalassaemia trait
A blood test can be done at any time to find out if you have the thalassaemia trait and are at risk of having a child with thalassaemia.
This can be particularly useful if you have a family history of the condition or your partner is known to carry thalassaemia.
Types Of Thalassemia
Alpha thalassaemia (or α-thalassaemia)
In order for an autosomal recessive disease to be transmitted, both parents must be at least heterozygotes, in order to transmit one affected gene each to their child.
In this case, the child bears a 25% possibility to get both affected genes and thus express the disease. There is also a 50% possibility that the child gets only one affected gene from one of the parents, thus becoming a heterozygote (carrier) and another 25% possibility to get no affected gene from either parents and thus be completely normal and incapable to transmit the disease any further, as explained in the following figure:
Beta thalassaemia (or β-thalassaemia)
In order for an autosomal recessive disease to be transmitted, both parents must be at least heterozygotes, in order to transmit one affected gene each to their child.
In this case, the child bears a 25% possibility to get both affected genes and thus express the disease. There is also a 50% possibility that the child gets only one affected gene from one of the parents, thus becoming a heterozygote (carrier) and another 25% possibility to get no affected gene from either parents and thus be completely normal and incapable to transmit the disease any further, as explained in the following figure:
