Currently, there are a huge number of hereditary diseases that a child receives along with genes from mom or dad. For some to manifest, it is necessary that both parents pass on the defective gene to their baby. One such disease is thalassemia. Few people know what kind of disease it is. In our article, we will try to deal with this.
What is Thalassemia
This is not even one, but a whole group of hereditary blood diseases that have a recessive inheritance. That is, the child will receive it if both parents pass on the diseased gene to him. In this case, it is said that there is a homozygous thalassemia. The disease is characterized by the fact that the production of hemoglobin is disrupted, and it plays a major role in the transport of oxygen throughout the body.
Hemoglobin is a protein, which in its composition has a protein part and a pigment part. The first consists of polypeptide chains: two alpha and two beta. Failure can occur in any of them, hence alpha thalassemia and beta thalassemia.
Violation of hemoglobin synthesis leads to a reduction in the lifespan of red blood cells, and this leads tooxygen starvation of cells and tissues. This process triggers a whole chain of reactions leading to the formation of various pathologies in the body.
Disease classification
There are several approaches to the classification of this disease. If we consider in which circuit the failure occurred, then we can distinguish:
- alpha thalassemia;
- beta thalassemia;
- delta thalassemia.
In each case, the severity of symptoms can vary significantly. Given this, allocate:
- light form;
- medium;
- heavy.
Depending on whether the child received the gene from both parents or from one, the disease is divided into:
- Homozygous, in this case, the diseased gene passes from mom and dad. This form is also called thalassemia major.
- Heterozygous. Inherited only from one parent.
All varieties are characterized by their symptoms and severity.
Causes of disease
Every disease has its own causes, thalassemia is also formed under the influence of genes that the child receives from parents. This genetic disease is particularly complex, but it is also the most common in the world.
Thalassemia is inherited in a recessive manner through the parent's autosome. This means that the probability of getting sick is 100% for someone who received defective genes for this trait from mom and dad.
A disease develops when the genes that are responsible for the synthesis of hemoglobin,mutation occurs. The alpha form of this disease is quite common in the Mediterranean, in Africa. Some associate thalassemia with malaria, as outbreaks of the disease are common in these regions.
Malarial plasmodium is blamed for the fact that a mutation occurs in the genes and thalassemia develops, the photo shows that a large number of cases are also found in Azerbaijan, about 10% of the total population. This confirms that the prevalence of the disease is associated with mutations, and climatic conditions also influence the mutation process.
Thalassemia major symptoms
If a baby develops homozygous or thalassemia major, symptoms begin to appear almost immediately after birth. These include:
- Skull shaped like a tower.
- The face has a Mongoloid appearance.
- The upper jaw is enlarged.
- After some time, the expansion of the nasal septum can be noted.
- When diagnosed with thalassemia, a blood test shows hepatomegaly, which will eventually lead to the development of cirrhosis of the liver and diabetes mellitus. A disturbed blood formula will lead to the deposition of excess iron in the heart muscle, and this is already fraught with heart failure.
- Due to impaired hemoglobin synthesis, tissues and cells experience constant oxygen starvation, which leads to the appearance of multiple pathologies throughout the body.
- The child lags behind, both mentally and physicallydevelopment.
- Closer to the age of one year, one can notice the growth of bone tissue on the feet due to the destruction of the cortical layer of the bones.
- Spleen enlargement seen on ultrasound
- Yellowness of the skin.
If a child is diagnosed with thalassemia, the symptoms are pronounced, which means that there is a high probability that he will not live to see his second birthday.
Thalassemia minor symptoms
When inheriting pathology from only one of the parents, we can talk about small or heterozygous thalassemia. Since there is a second he althy gene in the genotype, it significantly smoothes the manifestation of the disease, and the symptoms may not appear at all or give a smoothed picture.
Thalassemia minor has the following main symptoms:
- High and fast fatigue.
- Decreased performance.
- Frequent dizziness and headache.
- Pale skin with signs of jaundice.
- The spleen may also be enlarged.
Despite the smoothed symptoms, the danger lies in the fact that the body's susceptibility to all infections is greatly increased.
Disease diagnosis
Medicine has the ability to diagnose thalassemia in the early stages of development, diagnosis is based on laboratory blood tests. They immediately show that hemoglobin has a disturbed structure. You can even determine in which of the chains there are deviations.
Young children show signs of thalassemiabright enough, so usually there is no difficulty in making such a diagnosis. Parents, before deciding to have a child, should be examined, especially if the family has a carrier of the gene or is sick.
It is possible to diagnose thalassemia already in the early stages of pregnancy, take the amniotic fluid for analysis and examine it. It will always contain fetal erythrocytes, the study of which can establish the presence of pathology.
Early diagnosis is very important because it is possible to start treatment before the baby is born, which will give the most effective result.
Beta thalassemia
If a beta-type of the disease is formed, then the synthesis of beta-chains of hemoglobin is disrupted in the body. They are responsible for the production of hemoglobin A, which in an adult is 97% of the total number of molecules. If you understand, beta thalassemia - what it is, then we can say, based on a blood test, that there is a decrease in the number of beta chains, but their quality does not suffer.
The reason is gene mutations that disrupt the work of the genes responsible for the synthesis of chains. At present, it has already been established that there are not only mutations that cause disturbances in the functioning of genes, but there are also some sections of DNA that affect the manifestation of these mutations. As a result, it turns out that in people with the same mutations in the genes responsible for the synthesis of hemoglobin, the degree of manifestation of the disease can vary greatly.
Varieties of beta-thalassemia
The clinical picture of the disease may be different, depending on this, beta-thalassemia is divided into several groups. Not everyone is familiar with such a concept as thalassemia, that this disease depends on many genetic factors, and not everyone knows.
There are several states of genes that control the production of beta chains:
- Normal gene. It is in this state that he is in all he althy people.
- Gene virtually destroyed by mutation. The beta chain is not synthesized at all.
- A partially damaged gene can only partially do its job, so the synthesis of chains goes on, but not enough.
Given all this, the following types of thalassemia are distinguished:
- Thalassemia minor. A mild form of the disease is formed under the influence of only one damaged gene. According to external indicators, the person is completely he althy. Only blood tests show mild anemia and small red blood cells.
- Thalassemia intermedia. There is already a serious lack of beta chains. The process of hemoglobin formation is significantly impaired, and underdeveloped red blood cells are also formed. Anemia is already evident, but constant transfusions are not needed. Although this form can become more severe over time, everything will depend on the body's ability to adapt to a lack of hemoglobin.
- Thalassemia major. The mutation affects all genes responsible for the synthesis of beta chains. Such thalassemia (photos of patients can besee article) requires continuous blood transfusions to keep the patient alive.
Alpha Thalassemia
In hemoglobin, in addition to beta, there are also alpha chains. If their synthesis is disturbed, then we can talk about such a form as alpha thalassemia. The disease is manifested by the formation of only a beta chain, and this is fraught with the fact that hemoglobin of such a structure will not be able to fulfill its main purpose - to carry oxygen.
The manifestations of the disease will depend on the severity of the mutation of the genes that control the synthesis of alpha chains. This process is usually under the control of two genes, one child receives from the mother and the second from the father.
Varieties of alpha thalassemia
Depending on the degree of gene mutation, this form of the disease is divided into several groups:
- There is a mutation of one gene locus. In this case, you may not observe clinical manifestations.
- The defeat occurs at two loci, and they can be on the same gene or on different ones. A blood test is good at diagnosing low hemoglobin levels and small red blood cells.
- Three loci in the genes are prone to mutation. The transfer of oxygen to tissues and organs is impaired. In some cases, the spleen is still enlarged.
- Mutation in all loci leads to a complete lack of synthesis of alpha chains. With this form, fetal death occurs while still inside the mother's womb or immediately after birth.
If alpha thalassemia is mild, treatment may not be needed, but severevariety will have to be under the supervision of doctors all his life. Only regular courses of therapy can improve a person's quality of life.
Thalassemia treatment
We figured out thalassemia - what kind of disease is it. Now it is necessary to stop on treatment. It can be noted that therapy is aimed at maintaining hemoglobin at the required level and eliminating the heavy load of the body from a large amount of iron. Also, the following activities can be attributed to the methods of treatment:
- Severe disease requires regular blood or packed red cell transfusions. But this measure is only temporary.
- Recently, transfusions of defrosted or filtered erythrocytes have been done. This gives less side effect.
- If severe thalassemia is diagnosed, treatment is also supplemented with an almost daily administration of iron chelate.
- If the ultrasound shows too enlarged spleen, then it is removed. This operation is not done to children under the age of five. Despite the fact that after removal, there is an improvement in the condition, but after a while, deterioration and an increase in the risk of various infections are again noticeable.
- Bone marrow transplantation is considered the most effective treatment, but it is very difficult to find a donor for this procedure.
- Introduce foods that reduce iron absorption into your diet, such as nuts, soy, tea, cocoa.
- Take ascorbic acid, it helps to remove iron from the body.
In addition to the above methods of treatment, symptomatic therapy is also carried out, which alleviates the patient's condition.
Disease prevention
For doctors and geneticists it is clear if there is a diagnosis of thalassemia, that it is not curable. Have not yet found ways and methods to cope with this disease. However, there are measures to prevent it. The following preventive measures can be named:
- Performing prenatal diagnosis.
- If both parents have this disease, it is imperative to diagnose the fetus in order to identify this pathology. In some cases, it may be necessary to terminate the pregnancy.
- If you have relatives with this diagnosis in your family, it is advisable to visit a geneticist before planning a pregnancy.
In every organism there are a huge number of mutating genes, it is practically impossible to predict where and when a mutation will appear. This is what genetic counseling is for, to help couples understand their ancestry, or rather, diseases that are transmitted from one generation to another.
Prognosis for patients with thalassemia
Depending on the severity and form of the disease, the prognosis may be different. With thalassemia minor, patients live a normal life, and its duration is practically the same as the life expectancy of he althy people.
With beta thalassemia, a small proportion of patients survive to adulthood.
The heterozygous form of the disease practically does not require treatment, but withhomozygous, and even severe, it is necessary to do regular blood transfusions. Without this procedure, the patient's life is almost impossible.
Unfortunately, thalassemia is currently one of those diseases with which science has not yet learned to cope. You can only keep it under control to some extent.
