Alternative Names thalassaemia major , thalassaemia minor , Cooley's anaemia, Mediterranean anaemia
Definition Thalassaemia is an inherited condition that causes a problem in the production of haemoglobin. This may lead to anaemia, which is a low red blood cell count.
What is going on in the body? Haemoglobin carries oxygen from the lungs to the tissues. It also carries away the waste product of carbon dioxide. In thalassaemia, something goes wrong with the production of haemoglobin. When defective haemoglobin is incorporated into red blood cells, the red blood cells do not function properly. They are more likely to die off. This leads to anaemia.
Thalassaemia is an inherited disorder. In a person with thalassaemia, one or both parents are positive for the disease. When one parent is positive, the child will have thalassaemia minor. When both parents are positive, the child will have thalassaemia major.
What are the signs and symptoms of the disease? The symptoms of thalassaemia depend on the genetic defect and its severity. The more severe the genetic defect, the less haemoglobin that is produced and the more severe the anaemia that results. Thalassaemia minor may not cause any symptoms. If it does, the most common symptom is long-term, mild anaemia.
Someone with thalassaemia major usually has severe haemolytic disease. This means that the red blood cells are constantly being destroyed. This occurs faster than the body can replace them. Thalassaemia major is usually diagnosed by 1 year of age. The symptoms of thalassaemia major may include:
bony abnormalities, especially of the facial bones
What are the causes and risks of the disease? Thalassaemia is a common genetic disease. It is more common in people of African, Mediterranean, and Asian heritage
What can be done to prevent the disease? There is no way to prevent thalassaemia once the child is born. Genetic counselling may be helpful to couples with a family history of the disease. There is a 25% chance with each pregnancy that a child will be born with thalassaemia major if both parents carry the gene for thalassaemia.
How is the disease diagnosed? Thalassaemia is diagnosed through blood tests. A sample of blood is taken to look for a low red blood cell count, low haemoglobin levels, small red blood cells, or an abnormal red blood cell structure. Sometimes a more complex genetic analysis is needed.
What are the long-term effects of the disease? Thalassaemia minor usually does not cause long-term problems. Thalassaemia major, however, can result in stunted growth, problems in bone development, darkened skin, general growth problems, and death.
What are the risks to others? Thalassaemia is an inherited condition, so a person can passed it on to his or her children.
What are the treatments for the disease? With severe thalassaemia, regular blood transfusions are needed. The person will also require folic acid and other nutritional supplements.
An individual who has frequent red blood cell transfusions can develop iron overload. This can be avoided with chelation therapy. This is a process that removes excess iron from the body. This therapy may need to be started early in childhood.
Some treatments for thalassaemia are still being tested in clinical trials. These include:
changing the abnormal haemoglobin genes using medications similar to those used in cancer chemotherapy
specific gene therapy targeted at the abnormal chromosomes
These approaches are usually reserved for severe thalassaemia.
What are the side effects of the treatments? Frequent blood transfusions can lead to an iron overload. Excess iron can end up in various body tissues and cause skin discolouration, liver disease, and diabetes. Chelation, which involves daily injections of an iron-binding agent, can help eliminate the excess iron from the body.
There are risks with any blood transfusion. These include an allergic reaction, infection, and sometimes hepatitis or HIV, the virus that causes AIDS.
Bone marrow transplants can cause the body to attack the new bone marrow. Or the new bone marrow may not function at all.
What happens after treatment for the disease? A person with severe thalassaemia may need frequent blood transfusions for the rest of his or her life.
How is the disease monitored? Thalassaemia is monitored by frequent blood tests. The person will need to be followed closely by the doctor. Any new or worsening symptoms should be reported to the doctor.
Author: Linda Agnello, RN, BSN Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
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