Brief overview
- Description: Genetically caused disease of the red blood cells (erythrocytes) that leads to anemia.
- Diagnosis: The doctor diagnoses thalassemia by a special blood test and an analysis of the genetic material (DNA analysis).
- Causes: An inherited genetic defect that causes the body to make too little or no red blood pigment (hemoglobin).
- Symptoms: Anemia, fatigue, enlarged liver and spleen, growth disorders, bone changes, osteoporosis, among others; mild forms of thalassemia often have no symptoms.
- Prognosis: Thalassemias vary in severity. The earlier the symptoms are treated, the better the prognosis. A cure is currently only possible with stem cell transplantation; research is also being conducted into gene therapy approaches.
What is thalassemia?
The blood cells are usually smaller than normal due to the altered hemoglobin and have a shortened lifespan, causing anemia over time, accompanied by typical symptoms such as fatigue and accelerated heartbeat.
How does thalassemia develop?
Hemoglobin is a protein found in red blood cells and is produced in the bone marrow. It enables red blood cells to carry vital oxygen from the lungs to all parts of the body.
This allows fewer hemoglobin molecules to form and function. The red blood cells shrink and break down more. As a result, anemia occurs because the body is no longer supplied with sufficient oxygen due to the lack of red blood cells.
Depending on which protein chain (alpha or beta chain) is affected, a distinction is made between α-(alpha)-thalassemia and β-(beta)-thalassemia.
Alpha thalassemia
Beta Thalassemia
Beta-thalassemia is the more common form of thalassemia. In this form, the body makes too few or no beta hemoglobin chains.
There is also delta and gamma thalassemia, but both are very rare and usually have a mild course.
How is thalassemia diagnosed?
Family history
Since thalassemia is a hereditary disease, the family history usually provides the physician with initial clues. For this purpose, the physician asks, for example, whether there are known carriers of the disease in the family.
Blood test
To confirm the diagnosis, the physician performs a blood test including hemoglobin electrophoresis (Hb electrophoresis).
Hemoglobin electrophoresis
Depending on how the hemoglobin is composed, it moves different distances in a given time. Based on the distance traveled, the physician assesses whether the hemoglobin is normal or defective.
Diagnosis in babies
Doctors recommend that newborns with a family history of thalassemia have a blood test performed (e.g., during newborn screening). For this purpose, the doctor takes some blood (e.g. from the umbilical cord) right after birth and examines it for genetic changes. In this way, it is possible to detect the disease early and treat it in time.
Diagnosis during pregnancy
Doctors recommend that expectant parents who know they are carriers of thalassemia have this prenatal diagnostic test performed during the first twelve weeks of pregnancy.
Is thalassemia hereditary?
Thalassemias are hereditary. This means that people with thalassemia inherit the genetic defect from their parents and are already born with the disease.
Heredity: Alpha thalassemia
A total of four genes are involved in the formation of the alpha chains. In alpha thalassemia major, all genes inherited by the child from the parents are defective. It is the most severe form of alpha thalassemia. Children with this form are rarely able to survive and usually die before birth or a few days after. Only in a few cases is it possible to keep the children alive with the help of a stem cell transplant.
If only one parent passes on a defective gene to his or her child, the condition is referred to as alpha thalassemia minima. Affected individuals usually have no symptoms and live without impairment.
Inheritance: beta thalassemia
Beta thalassemia also has different degrees of severity. It is divided into minor, intermedia and major.
Thalassemia major (also called Cooley anemia) is the most severe form. It occurs when both parents pass the genetic defect on to the child.
Beta-thalassemia intermedia is an intermediate form. People with this form have also inherited the defective genes from both parents. Their symptoms are usually not quite as severe as those of the major form. They need blood transfusions only occasionally.
In beta-thalassemia minor, affected individuals have inherited only one defective beta-hemoglobin chain gene from one parent. The other parent has passed on a functional gene to the child.
If both parents are affected by beta thalassemia minor, there is a 25 percent chance that the child will inherit both mutations and develop thalassemia major or intermedia. There is a 50 percent chance that the child will inherit a minor form, and a 25 percent chance that the child will be healthy.
Where do thalassemias occur?
Thalassemia is also colloquially known as Mediterranean anemia because it is widespread in Mediterranean countries such as Italy or Greece. However, it also occurs in the Near and Middle East and in parts of Africa and Asia. In Central Europe, thalassemia has spread through worldwide trade links and migration.
How common is the disease?
According to estimates, around 60,000 children are born with thalassemia each year worldwide. For Germany, experts suspect a number of 500 to 600 people with a severe form of thalassemia. About 200,000 people in Germany suffer from the mild form of thalassemia. There are currently no exact figures for Austria and Switzerland.
How is thalassemia treated?
Non-transfusion-dependent treatment
Mild forms of thalassemia usually do not require treatment. During pregnancy, however, it is possible in rare cases for pregnant women to develop severe anemia due to mild thalassemia. These women then require regular blood transfusions to protect both mother and child.
Transfusion-dependent treatment
The additional blood transfusions often result in an excess of iron. In these cases, the doctor prescribes drugs that remove the excess iron from the body again (so-called chelators or iron chelating agents). The doctor injects these under the skin (subcutaneously) in the hospital or the affected person takes tablets at home.
Stem cell transplantation
Gene therapy
For people with transfusion-dependent beta-thalassemia, the European Medicines Agency approved a gene therapy drug in 2019. In this gene therapy, stem cells are taken from the affected person’s bone marrow and an intact gene is introduced with the help of the drug. The affected person then gets his stem cells back. They can now form healthy red blood cells and normal blood pigment.
The above-mentioned preparation is no longer available in Europe.
Nutrition and lifestyle
People with thalassemia are able to positively influence their disease course through proper nutrition and lifestyle adjustments. Please note the following:
- Eat a balanced diet.
- Avoid foods with extremely high iron content (e.g. liver).
- Get enough calcium from your diet (e.g. milk, yogurt, cheese, spinach leaves, broccoli).
- Do not drink alcohol.
What are the symptoms of thalassemia?
The severity of the symptoms depends on how much of the hemoglobin is abnormally changed. People with a mild form of thalassemia usually have no or few symptoms.
If left untreated, however, babies with a severe form of thalassemia begin to show health problems by the fourth or fifth month of life.
Anemia
- You are pale or have yellowish skin.
- You are tired all the time.
- You feel dizzy.
- You have a headache.
- They have an accelerated heartbeat.
- They get short of breath quickly during physical activity.
- They often have an enlarged liver and spleen.
- Their development is often disturbed.
At first glance, thalassemia resembles iron deficiency anemia. However, iron levels are decreased in iron deficiency, while they are usually normal in thalassemia.
- Bone deformities
- Frequent infections
- Heart problems
- Diabetes mellitus
- Osteoporosis
Bone changes
People with thalassemia major or intermedia often also show altered bone growth:
- The skull bone increases in size.
- Forehead, upper jaw and zygomatic bone are bulging.
- Ribs and vertebral bodies are bent.
- You have an increased risk of bone fractures.
- You have bone pain.
- You get osteoporosis.
Excess iron
In addition, the body mistakes the anemia for an iron deficiency and tries to compensate for it by absorbing more iron from food. In addition, the body produces an excessive number of blood cells. The liver and spleen then work at full speed to break these down again.
The excessively high iron concentration causes further symptoms in those affected, such as:
- Heart muscle weakness (cardiac insufficiency)
- Cardiac arrhythmias
- Liver dysfunction
- Diabetes (diabetes mellitus)
- Short stature
- Hypothyroidism (underactive thyroid gland)
- Disorders of vitamin D metabolism
When to see a doctor?
Since severe forms of thalassemia often become apparent in the first months of life, it is important that parents consult a pediatrician as soon as possible at the first signs (e.g., pallor).
How can you prevent it?
There, trained specialists use a genetic blood test to determine for couples possible genetic risks associated with pregnancy.
People with a known family history of thalassemia are also advised to seek counseling before becoming pregnant.
Regularly measuring the body temperature helps to detect infections as early as possible and to treat them as quickly as possible. If the fever exceeds 38.5 degrees Celsius, a doctor should be consulted immediately. It is possible that an infection is the cause.
It is also particularly important for those affected to have regular medical check-ups. Only in this way is it possible to carefully monitor the course of the disease, detect complications at an early stage and treat them.
A complete cure for thalassemia is currently only possible through stem cell transplantation. The life expectancy and quality of life of those affected has steadily increased due to improved treatment and better education.
The gene therapy approved by the European Medicines Agency in 2019 has been withdrawn from the market again by the manufacturer in 2021.
What is the prognosis for thalassemia?
In more severe forms, it is often equally possible to achieve an almost normal life expectancy with the right and early treatment (e.g. regular blood transfusions). However, a lifelong, continuous and intensive therapy is then necessary. Sometimes the disease can be cured by stem cell transplantation.
