Hemoglobin is a protein found in red blood cells, whose role is to transport oxygen in order to distribute it to the body. Beta thalassemia is a genetic disorder characterized by an abnormality of hemoglobin. The degrees of severity vary depending on the form of the disease.
Hemoglobin is made up of four "bricks", called chains: two "bricks" called alpha and two "bricks" called beta. Beta thalassemia is caused by insufficient production of beta chains which therefore results in a decrease or absence of overall hemoglobin.
Beta thalassemia: what are the symptoms of this hemoglobin abnormality?
The manifestations of beta thalassemia depend on the degree of alteration of the beta genes. This pathology can therefore take different forms:
Beta thalassemia major or Cooley's anemia:
This form of the disease is caused when both beta genes are affected. The production of hemoglobin is then insufficient or even zero. Most patients develop anemia which can lead to fatigue and feelings of weakness. The lips, tongue and palms are also very pale or even yellowish. Cooley's anemia particularly affects young children: infants begin to eat less, cry more often and become short of breath when feeding bottles. They may also have jaundice.
If this absence of hemoglobins is prolonged, it can cause hepatomegaly, which is an increase in the volume of the liver or splenomegaly, which is characterized by an increase in the volume of the spleen. Bone damage can also occur in children: the bones of the face thicken with deformities of the jaw or flattening of the root of the nose. Stunting is also possible.
Stones can form in the gallbladder and trigger severe stomach pains with colic. A cholecystectomy can be performed to remove the gallbladder and relieve the sick.
In some cases, doctors decide to remove the spleen in patients with Cooley's anemia. Following this surgery, called splenectomy, some adults, but especially children, are more likely to develop an infection such as pneumonia, meningitis, septicemia or the flu.
Intermediate beta thalassemia
In these forms of beta thalassemia, both beta genes are altered, but they manage to make reduced hemoglobin. Symptoms are less severe than Cooley's anemia and appear later, around the age of two. Children are growing normally, but their puberty may be slightly delayed.
The most common manifestation is an enlarged spleen, which causes pain and discomfort. The doctor in charge of the patient can therefore decide to perform a splenectomy in order to remove this organ.
Beta thalassemia minor
Only one of the beta genes is affected by an anomaly. The other gene is intact and manages to produce enough hemoglobin to compensate for this mutation. This form of beta thalassemia therefore has no effect on the patient's health.
What is the evolution of beta thalassemia?
The course of this hemoglobin abnormality depends on its severity. When the patient is affected by a minor form, the patient does not risk anything. In the case of intermediate forms, growth is almost normal in a child, but blood transfusions are sometimes recommended to compensate for the lack of hemoglobin. But in the case of severe forms, these blood transfusions are necessary several times a month. Over the years, complications may appear such as:
How is beta thalassemia diagnosed?
When an infant has symptoms of anemia, the attending physician may order blood tests. These blood tests confirm anemia and the normal level of fetal hemoglobin which is supposed to disappear a few weeks after birth. In babies affected by beta thalassemia, fetal hemoglobin is produced in large quantities to compensate for the absence or insufficiency of normal adult hemoglobin.
Beta thalassemia is a genetic disease. A prenatal diagnosis is therefore possible with each pregnancy in order to detect it. Two techniques make it possible to identify it:
- amniocentesis: this method consists in analyzing the floating cells in the amniotic fluid in order to look for the genetic anomaly.
- removal of chorionic villi: it is a small amount of placental tissue
What are the treatments to treat beta thalassemia?
Severe forms of severe forms of beta thalassemia can sometimes be treated with a bone marrow transplant. But in most cases, regular blood transfusions are needed to correct anemia and avoid complications.
Sources: the platform Orphanet
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