Thalassemias are a set of hereditary blood diseases affecting the production of hemoglobin (the protein responsible for transporting oxygen). They vary in severity: some cause no symptoms while others are life threatening. A bone marrow transplant is considered in the most serious cases.

Definition of thalassemia

Thalassemia is characterized by a defect in the production of hemoglobin. As a reminder, hemoglobin is a large protein present in red blood cells (red blood cells) whose role is to ensure the transport of dixoygene from the respiratory system to the rest of the body.

It is said that thalassemia is a disease of the blood. The transport function of red blood cells is impaired, which can have serious consequences on the body. At this point, it is important to note that there are several types of thalassemia that do not have the same characteristics or the same degree of severity. Some have no symptoms while others are life threatening.

Causes of thalassemia

Thalassemias are genetic diseases. They are due to the alteration of one or more genes involved in the synthesis of hemoglobin, and more exactly to the alteration of the genes involved in the production of hemoglobin protein chains. There are four of these: two alpha chains and two beta chains.

Each of these chains can be affected in thalassemia. We can also distinguish:

• alpha-thalassemias characterized by an alteration of the alpha chain;
• beta-thalassemias characterized by an alteration of the beta chain.

The severity of alpha thalassemias and beta thalassemias depends on the number of genes altered. The more important it is, the greater the degree of severity.

Diagnosis of thalassemia

The diagnosis of thalassemia is made by blood test. The complete blood count makes it possible to evaluate the appearance and the number of red blood cells, and thus to know the total quantity of hemoglobin. Biochemical analyzes of hemoglobin make it possible to distinguish alpha-thalassemias from beta-thalassemias. Finally, genetic analyzes make it possible to evaluate the number of altered genes and thus to define the severity of thalassemia.

Persons concerned

Thalassemias are inherited genetic diseases, that is, transmitted from parents to their children. They mainly reach people from the Mediterranean rim, the Middle East, Asia and sub-Saharan Africa.

In France, the prevalence of alpha-thalassemia is estimated at 1 in 350 people. The incidence of beta-thalassemia is estimated at 000 birth per 1 per year worldwide.

The symptoms of thalassemia vary greatly from case to case, and depend mainly on the degree of alteration of the genes involved in the production of hemoglobin protein chains. Thalassemias may be symptom-free in their minor forms and be life-threatening in their more severe forms.

The symptoms mentioned below only concern the intermediate to major forms of thalassemia. These are just the main symptoms. Very specific symptoms can sometimes be seen depending on the type of thalassemia.

Anemia

The typical sign of thalassemia is anemia. This is a lack of hemoglobin which can result in the appearance of different symptoms:

• tiredness ;
• shortness of breath;
• pallor;
• discomfort;
• palpitations.

The intensity of these symptoms varies depending on the severity of the thalassemia.

Jaundice

People with thalassemia may have jaundice (jaundice) that is visible on the skin or the whites of the eyes. 

Gallstones

Stone formation inside the gallbladder can also be seen. Calculations are like “little pebbles”.

Splenomegaly

Splenomegaly is an enlargement of the spleen. One of the roles of this organ is to filter the blood and filter harmful substances including abnormal red blood cells. In thalassemia, the spleen is strongly mobilized and gradually increases in size. Pain may be felt.

Other, rarer symptoms

More rarely, severe forms of thalassemia can lead to other abnormalities. For example, it can be observed:

• hepatomegaly, that is, an increase in the size of the liver;
• bone deformities;
• delayed child development;
• ulcers.

The management of thalassemia is essential to limit the occurrence of these complications.

The management of thalassemia depends on many parameters including the type of thalassemia, its severity and the condition of the person concerned. The most minor forms do not require treatment while the severe forms require very regular medical monitoring.

The treatments mentioned below only concern the intermediate to major forms of thalassemia

Correction of anemia

When the lack of hemoglobin is too great, regular blood transfusions are necessary. They involve injecting the person concerned with blood or red blood cells taken from a donor to maintain an acceptable level of red blood cells in the blood.

Vitamin B9 supplementation

It may be recommended to start daily vitamin B9 supplementation because the need for this vitamin is increased in cases of thalassemia. Vitamin B9 is involved in the production of red blood cells.

Splenectomy

A splenectomy is the surgical removal of the spleen. This operation can be considered when the anemia is very important.

Treatment of iron overload

People with thalassemia have an overload of iron in their body. This accumulation can lead to different complications. This is why iron chelators are offered to remove excess iron.

Bone marrow transplant

A bone marrow transplant is the only treatment that can permanently cure thalassemia. This is a heavy treatment that is only offered in the most severe forms of the disease.

Thalassemia is an inherited genetic disease. There is no preventive measure.

On the other hand, genetic tests make it possible to detect healthy carriers (people who have one or more altered gene (s) but who are not sick). A couple of healthy carriers should be informed of the risk of giving birth to a child with thalassemia. In some cases, this risk can be assessed by a geneticist. Prenatal diagnosis can also be considered under certain conditions. It should be discussed with your doctor.