Red blood cells transport oxygen throughout the body; hemoglobin is the protein in red blood cells that actually carries the oxygen. Thalassemia is a group of disorders that affect the body's ability to produce normal hemoglobin.
People who have thalassemia produce fewer healthy hemoglobin proteins, and their bone marrow produces fewer healthy red blood cells.
Thalassemias can cause mild or severe anemia and other complications that can occur over time (such as iron overload). Symptoms of anemia include fatigue, difficulty breathing, dizziness, and a pale skin tone.
The type of thalassemia you have depends on the number of gene mutations you inherit from your parents and which part of the hemoglobin molecule is affected by the mutations. The more mutated genes, the more severe your thalassemia. Hemoglobin molecules are made of alpha and beta parts that can be affected by mutations.
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:
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:
The symptoms of thalassemia vary depending on the type of thalassemia.
Symptoms will not show until the age of 6 months in most infants with beta thalassemia and some types of alpha thalassemia. This is because neonates have a different type of hemoglobin, called fetal hemoglobin.
Alpha Thalassemia Symptoms: Different people will have different symptoms, based on which type of alpha thalassemia is inherited. Common symptoms for each type may include:
Beta Thalassemia Symptoms:
Different people will have different symptoms, based on which type of the disorder is inherited. Beta thalassemia major. This is the most severe type of this disorder. Children born with this type will have symptoms early in life that include:
Over time more symptoms will appear, including:
Without treatment, the spleen, liver, and heart become enlarged. Bones can also become thin, brittle, and deformed.
People with this condition will need frequent blood transfusions and may not live a normal lifespan. Iron builds up in the heart and other organs from blood transfusions. This can cause heart failure as early as the teens or early 20s.
Thalassemia minima. This type often causes no symptoms.
Thalassemia intermedia. This type can cause symptoms of moderate to severe anemia including:
Possible complications of thalassemia include:
In cases of severe thalassemia, the following complications can occur:
Thalassemia is inherited. This means it’s passed from parent to child through genes. A gene is part of the body’s cells that stores instructions for the way your body grows, looks and works. If someone in your family has or had thalassemia, you can say you have a family history of thalassemia.
Sometimes the instructions in genes change. This is called a gene change or a mutation. A gene change can cause a gene to not work correctly. It also can cause birth defects or other health condition. Parents can pass gene the gene change for thalassemia to their children.
If you have thalassemia or a family history of thalassemia, talk to a genetic counselor. This is a person who is trained to help you understand about how genes, birth defects and other medical conditions run in families, and how they can affect your health and your baby’s health.
Most children with moderate to severe thalassemia show signs and symptoms within their first two years of life. If your doctor suspects your child has thalassemia, he or she may confirm a diagnosis using blood tests.
If your child has thalassemia, blood tests may reveal:
Blood tests may also be used to:
Testing can be done before a baby is born to find out if he or she has thalassemia and determine how severe it may be. Tests used to diagnose thalassemia in fetuses include:
Assisted reproductive technology
A form of assisted reproductive technology that combines preimplantation genetic diagnosis with in vitro fertilization may help parents who have thalassemia or who are carriers of a defective hemoglobin gene give birth to healthy babies. The procedure involves retrieving mature eggs and fertilizing them with sperm in a dish in a laboratory. The embryos are tested for the defective genes, and only those without genetic defects are implanted into the uterus.
Signs and symptoms are usually mild with thalassemia minor and little, if any, treatment is needed. Occasionally, you may need a blood transfusion, particularly after surgery, after having a baby or to help manage thalassemia complications.
People with severe beta-thalassemia will need blood transfusions. And because this treatment can cause iron overload, they will also need treatment to remove excess iron. An oral medication called deferasirox (Exjade, Jadenu) can help remove the excess iron.
Treatments for moderate to severe thalassemia:
Treatments for moderate to severe thalassemia may include:
Stem cell transplants
A stem cell transplant is a possible cure for thalassemia, though there are risks of serious complications and even mortality. Stem cell transplants tend to have a better outcome in younger people. This therapy may be considered for a person who has a suitable donor.
A stem cell transplant involves the administration of high-dose chemotherapy to eliminate thalassemia-producing cells in the bone marrow, and subsequent replacement with normal blood-making cells from a donor, resulting in a lifelong cure if successful.
Frequent Blood transfusions
Blood transfusions are typically given to people with anemia accompanied by other complications, such as poor growth, enlarged spleen, evidence of heart disease, as well as in the case of pregnancy. Blood transfusions have associated risks and are only carried out when absolutely necessary, so those who have anemia without other symptoms may be advised against a transfusion.
Blood transfusions supply normal red blood cells to the affected person. This corrects the anemia temporarily, improving health and helping children to grow normally. However, the red blood cells have a limited lifespan, so the transfusion is normally repeated every three or four weeks.