Homozygous thalassemia. Thalassemia: what kind of disease, where does it come from. Genetic variants of alpha thalassemia

Thalassemia is a blood pathology characterized by disturbances in the formation of one or several hemoglobin chains in red blood cells. This causes the development of small, low-quality red blood cells.

With this disease, there is a deterioration in the transport of oxygen to the tissues and cellular elements of the body. This causes their hypoxia, and signs of the disease become obvious.

Previously, the disease was more often observed in climatically hot places where people suffer from malaria: Southeast Asia, Africa, and Mediterranean countries. But in the modern world it is diagnosed in a variety of regions due to population migration. The pathology develops equally in females and males.

Every year, about 200,000 children are born with this disease, 50% of them are diagnosed with a homozygous form of β-thalassemia. The latter quickly leads to death.

In the heterozygous form, the disease does not manifest itself; this is possible only in extreme situations. However, the risk of its development in descendants is high; they can get it as a hereditary pathology.

Causes of Thalassemia

They have been studied well, since the disease is quite common. It is reliably known that the first changes are observed when the synthesis of hemoglobin protein chains is disrupted, which is able to bind to oxygen molecules and transport them to all tissues of the body.

Most often, the disease develops due to genes that children inherit from their parents. In those of them that are responsible for the synthesis of hemoglobin, a mutation is detected.

When studying the structure, a pigment is discovered, which includes iron and 2 pairs of protein compounds: alpha and beta chains. If the synthesis of one of them is disrupted, then the second accumulates.

Such changes are provoked by those genes that are responsible for the formation of the hemoglobin protein. With such a mutation, the correct set of amino acids in the chain is disrupted. The phenomenon is also characteristic of the malaria pathogen.

Heredity in a child can manifest itself in two ways:

1. Homozygous type of pathology - from mom and dad at the same time.
2. Heterozygous - from one of the parents.

Classification

If the abnormal hemoglobin protein is inherited from both parents, then this is a severe form, which is characterized by pronounced manifestations. This is thalassemia major, or Cooley's disease (after the doctor who described it).

It is inherited in a recessive manner (bihallelic system), based on a decrease in the synthesis of polypeptide chains. If this occurs on the part of one parent, then in the absence of extremely unfavorable circumstances there are no signs.

The modern classification identifies the following forms of the disease:

• Alpha thalassemia. It is observed in the absence of one or more genes, of which normally there should be two from the mother and father. This is the amount that ensures sufficient production of alpha globin chain proteins. If two genes are missing, symptoms of anemia may occur. With a deficiency of three genes, hemoglobinopathy H is diagnosed, which is clearly manifested by symptoms of anemia. The absence of four genes is a rather rare phenomenon, which is called “hydrops fetalis”. Such children die before, during or immediately after birth.
• Beta thalassemia occurs when one or two genes are disrupted, which normally comes from one father and mother. Not enough beta globin protein is produced. When one gene is modified, a person is a carrier of the disease, and the manifestation of moderate anemia is possible. When both genes change simultaneously, beta thalassemia intermedia (Cooley's anemia) is diagnosed. With the main one, a severe form of anemic syndrome also develops. The homozygous beta form reveals itself by the child’s year of life and differs in the manifestation of symptoms. Heterozygous (thalassemia minor) is characterized by vague symptoms or completely absent symptoms.

It should be taken into account that in some cases the homozygous form is mild and cannot be classified as thalassemia major, so it is marked as intermediate.

This pathology has three degrees:

1. Heavy. The abnormal changes are so strong that the child dies in the first year of life.
2. Medium-heavy. A child can live for about eight years.
3. Light form. An adult dies before reaching old age.

Despite a common diagnosis, β-thalassemia among individuals can vary widely in test results, presentation of signs, clinical course, treatment, and future prognosis.

Symptoms and manifestations

Signs depend on the form and time of occurrence of the mutation. Thalassemia major occurs with homozygous origin and manifests itself in children immediately after birth:

• Elongated upward cranium.
• The upper jaw is more developed compared to the lower jaw.
• The facial skeleton of the skull resembles a Mongoloid one.

By the age of one year, the following signs are observed:

• Expansion of the nasal septum, flattened shape.
• Formation of abnormal bone growths in the foot area.
• Bite disorders.
• Yellowness of the skin due to dysfunction of the spleen.

Oxygen deficiency in tissues causes the following symptoms:

• Enlarged liver, development of early cirrhosis.
• Formation of heart failure. Excess iron accumulates on the myocardial muscle and disrupts the contractile activity of the heart muscle.
• Delay in physiological and intellectual development.
• Formation of diabetes mellitus.

Adults experience the following symptoms:

• The formation of ulcers on the skin, they are provoked by abnormal disturbances in blood circulation.
• Frequent pneumonia.
• Regular bone fractures.
• Inflammatory processes in the gallbladder associated with the deposition of stones.
• Cardiosclerosis is a heart pathology characterized by the growth of the connective scar in the myocardium, muscle replacement and valve deformation.
• Formation of sepsis in infectious pathologies.
• Sexual disorders.

With the development of an intermediate form of the disease, there are no changes in the person’s appearance, mental and physical development are normal, but there is an enlargement of the spleen and fragility of the bones.

Signs of thalassemia major

Observed immediately after birth:

• Elongated skull shape.
• Mongoloid face type.
• Enlargement of the upper jaw.
• Enlargement of the nasal septum.

A blood test indicates hepatomegaly, which ends in the formation of cirrhosis and diabetes.

If a diagnosis of thalassemia is made at birth, and the signs are clear, then most often such children can live for about a year.

Symptoms of Thalassemia Minor

If the gene mutation is passed on from one of the parents, then thalassemia minor develops. In this case, the symptoms are vague or do not appear at all. The clinical picture is as follows:

• Increased fatigue.
• Deterioration in performance.
• Regular headaches, causeless dizziness.
• Pale skin with jaundice.
• Enlarged spleen.

The greatest danger of this condition is the increased risk of infection entering the body.

Diagnosis of the disease

The examination includes several stages:

• Anamnesis collection. Dangerous pathologies that were diagnosed in a woman during pregnancy and could cause the development of the pathology are identified.
• Assessment of the course of the gestation period.
• A thorough examination by a doctor: the general condition of the patient, the condition and color of the skin are assessed, and the abdominal area is palpated to determine hepatosplenomegaly.
• Interviewing parents or the patient himself to determine the severity of symptoms and severity of the disease.

The following laboratory tests are also prescribed:

• Blood chemistry.
• PCR tests.
• Study of the biological synthesis of hemoglobin chains.
• General blood test.
• Hemoglobin electrophoresis.

It is also necessary to carry out instrumental diagnostic methods:

• Abdominal ultrasound (detects an enlarged spleen).
• X-ray of bones.
• Bone marrow puncture.
• Development of the fetus in the womb.

If a homozygous form of pathology is detected, artificial termination of pregnancy is prescribed.

Treatment

Having determined what it is and what the signs are, it is necessary to choose treatment methods. Therapeutic measures are primarily aimed at normalizing the amount of hemoglobin.

In addition to this, there are other treatment methods:

• In severe forms of the disease, frequent blood transfusions are necessary, but this gives a temporary result.
• Iron chelate is prescribed.
• In modern medicine, it is possible to carry out transfusions of thawed or filtered red blood cells. This procedure is safer for children.
• If the spleen is enlarged, it is recommended to remove it. Surgical treatment is possible only after 5 years of life; it is necessary to take into account the increasing risk of infection.
• Bone marrow transplantation, but finding a donor is problematic.

Clinical recommendations include a special diet, which involves taking nuts, tea, soy, cocoa (foods that interfere with the absorption of iron). Taking ascorbic acid, which helps remove iron from the body.

Possible complications

In moderate and severe forms, treatment measures are aimed at prolonging life and eliminating possible complications, such as:

• Pathologies of the heart and liver. High levels of iron in the body can cause damage to various tissues, the heart muscle and liver being most susceptible to this. This often causes death, so regular blood transfusions are necessary.
• Penetration of infection into the body is also often the cause of death of the patient, especially for those who have had surgery to remove the spleen.
• Osteoporosis. With this pathology, bone elements are susceptible to frequent fractures.

Prevention

It is impossible to cure thalassemia, so it is necessary to take preventive measures, which include the following:

• Diagnosis during pregnancy, especially if both parents have thalassemia.
• Conducting genetic research.
• If necessary, an artificial termination of pregnancy is performed.

Forecasts

When diagnosed with thalassemia minor, the prognosis is good, the person leads a normal life, the duration of which is almost the same as that of a healthy person.

With beta thalassemia, only some patients are able to survive to adulthood.

The severe homozygous form requires ongoing treatment, since only interventions such as blood transfusions keep the patient alive.

Thalassemia refers to diseases, when detected, they speak of X-linked recessive inheritance, that is, thalassemia does not have a high degree of development. The chances of encountering it are higher for those children in whom both parents have a history of the disease and will pass on the abnormal gene to their offspring. If such a problem is relevant only for one of the parents, then the likelihood that the child will also suffer from thalassemia is small.

In thalassemia, processes associated with the synthesis of polypeptide chains, which are part of the structure of hemoglobin, are disrupted. For this reason, special red blood cells appear that have a slightly different shape and are unable to transport oxygen to the cells and tissues of the body. Serious oxygen starvation, which all tissues and systems experience, leads to severe consequences that are clearly visible visually.

Thalassemia is not widespread, but is more common diagnosed in certain regions where the chances of encountering malaria are higher, that is, in southern Asia and western Africa. In some areas of Latin America, cases of thalassemia are also recorded. Experts associate this feature with the specific operation of the protective system. It is believed that in this way the organisms of the residents received a primary compensatory and protective mechanism against malarial plasmodium - patients suffering from thalassemia do not suffer from malaria.

Classification

Thalassemia is characterized by disruption of globin chains. This could be a failure in one or more circuits. In any case, the production of the important iron-containing protein hemoglobin in the blood is disrupted, and the normal functioning of red blood cells becomes impossible. Based on information about the synthesis of which particular globin chain is impaired, and which pair of chromosomes is responsible for this, several groups and types of the disease are distinguished:

• Alpha thalassemia. This type is characterized by the presence of a defect in one or several genes (HBA1 and HBA2) located in the 16th pair of chromosomes, which ensures the synthesis of globin alpha chains. In this case, the synthesis of beta chains proceeds normally, but due to disturbances in the alpha chains the formation of an adequate globin complex is not possible. In this case, it is the number of available genes with a mutation that determines whether we will be talking about asymptomatic carriers, about alpha-thalassemia minor with a minimum of symptoms, or whether the patient will face hemoglobinopathy, in which thalassemia can be severe and even cause death. Also, with alpha thalassemia, intrauterine hydrops may develop, leading to fetal death.
• Beta thalassemia according to all medical statistics, it is more common. This type is characterized by the location of the incorrect gene in the 11th pair of chromosomes. Eventually problems arise with the synthesis of beta-globin chains. The hemoglobin complex in this type is unstable and is quickly destroyed along with erythroblasts and red blood cells. With the development of this type of pathology, we can talk about an intermediate form, in which the required amount of hemoglobin is still produced, so the symptoms are not pronounced. It is also possible to develop beta thalassemia minor, in which clinical manifestations may not occur at all, since the amount of globin beta chains produced by the body is reduced only slightly. Some cases are associated with the development of Cooley's anemia - thalassemia major, the most severe type of the disease.

There is also a mixed form, which is quite rare. In the mixed form, disturbances are observed in both the alpha chains of globins and the beta chains. With such failures, the fetus has no chance of survival, and the child dies in the mother’s womb.

Causes

The cause of thalassemia is inheritance of certain problem genes. If a future child inherits genes with a mutation from both his father and mother, which happens quite rarely, he will most likely face the disease. If a dangerous mutant gene is hidden in the chromosomes of only one of the parents, the baby can become a carrier. In this state of affairs the likelihood of developing the disease is low, but there is still a certain risk, and theoretically it is estimated by doctors at 25-50%.

But most often, no external manifestations will be observed, and the newborn will be completely healthy. Experts do not yet know what exactly leads to such a genetic mutation.

Symptoms

Since the development of the disease is associated with the destruction of red blood cells, the external signs of thalassemia are very noticeable even in a newborn - the patient’s skin has a yellow or even “canary” color. When palpating, the doctor usually notices that the liver and spleen are slightly enlarged in size. The ultrasound results confirm this. The liver becomes larger due to the deposition of the pigment hemosiderin. Gradually, the size of the organ may decrease and its density will increase.

Since the disease triggers certain negative processes in the body, leading to tissue hypoxia, the child has disturbances in the formation of bone structures, and problems in physical and mental development are observed. External manifestations of thalassemia also include pronounced Mongoloid type of face and tower-shaped head. As a rule, the upper jaw is abnormally large. Over time, there is a widening of the nasal septum. The gradual destruction of the cortical layer of bones will lead to the fact that, approximately by the end of the first year of life, the bone tissue in the area of ​​​​the feet will significantly increase in a small patient.

An important sign may be deterioration of general condition accompanied by severe shortness of breath. Usually, shortness of breath is associated with a deterioration in the condition of the cardiovascular system and possible heart failure, but in the presence of thalassemia, the heart and blood vessels may be in perfect order, and shortness of breath may occur with the slightest physical effort. The patient is also concerned about loss of strength, increased fatigue, almost constant dizziness, loss of appetite and other unpleasant symptoms characteristic of anemia.

Diagnostics

Diagnosis of thalassemia is the responsibility of the hematologist. If necessary, the doctor can invite experts from other fields for further work, since the negative consequences of blood disease are observed in all organs and systems of the body, and the problems must be differentiated. As part of diagnosing the disease, specialists prescribe:

• general blood test performed on an empty stomach;
• analysis of blood biochemistry, which requires compliance with certain rules of physical activity, taking medications and nutrition during the day;
• PCR, which identifies the problematic gene and its chromosome, which allows you to confirm or exclude the suspected diagnosis with 100% certainty;
• Ultrasound, which helps identify changes in the shape, size and structure of internal organs, especially the liver, kidneys and spleen;
• bone marrow puncture, without which it is impossible to judge its composition and the nature of malfunctions in the hematopoietic system;
• X-ray examination is necessary to create a complete picture regarding the condition of the skeleton and internal organs;
• specific laboratory blood tests to determine the degree of damage to the hematopoietic system.

Equally important is a dialogue with the patient, during which you can obtain information about the family history of the disease and possible genetic abnormalities.

Treatment

Despite all efforts, geneticists and pharmacologists have not yet been able to develop effective methods that can cure thalassemia. More often bone marrow transplant is used, but its implementation is associated with many difficulties and risks and is not always possible. Therefore, at this stage, all efforts of doctors are limited to influencing the intensity of symptoms and preventing complications.

Patients with mild thalassemia do not require special treatment, they are only asked get your blood tested regularly and follow some recommendations regarding lifestyle and nutrition. In cases of more complex forms of thalassemia, patients are prescribed medications and a diet designed to increase the level of hemoglobin and red blood cells. The patient is also recommended methods and means that can rid the body of excess iron and urates, including blood transfusions. In some cases, the patient may be advised to have the spleen removed.

Complications

Even if the little patient manages to survive because he is faced with a less dangerous type of illness, unfortunately, no one can guarantee him a healthy life. Most often, children with thalassemia suffer from problems with joint tissue; they are diagnosed with myocardial dystrophic changes, diabetes, and there are frequent cases of cirrhosis.

Prevention

As with many hereditary, genetically determined diseases, there is no need to talk about the possibility of preventing thalassemia.

Forecast

For young children, especially newborns, thalassemia poses a real and very serious threat. If a newborn patient is diagnosed with thalassemia major, the prognosis for the patient is bleak. Already within the first year of life the child may die- for this type of illness characterized by high mortality. If we are talking about a less severe form and active treatment of thalassemia, the patient has every chance of survival.

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A disturbance in the overall composition of components present in the blood can trigger the occurrence of a huge number of diseases, many of which are familiar to patients. However, there are also those about which they have no idea. In this article we will pay attention to one of these ailments, studying in more detail what kind of disease thalassemia is, what are the methods for diagnosing it and how to further combat the disease.

Thalassemia and its classification

Many parents, faced with this disease, wonder what thalassemia is? Thalassemia is a so-called group of diseases that involves a violation of the process of synthesis of hemoglobin chains. In medicine, this disease is considered hereditary, that is, having a predisposition in a child at the genetic level. It should be noted that this syndrome is a fairly common phenomenon among newborn babies.

Depending on the course of the disease and its form, thalassemia can be divided into:

• severe - can only be detected in a child during the first year of life, since it is during this period that the child will be able to live with such disorders of the blood composition;
• fatal - the disease is detected in a child under 8 years of age, in this case the disease is less severe than in the previous form;
• mild - it is detected at a more conscious age, however, even in this form a person can live for a relatively short time.

In addition, this disease is divided as follows. Highlight:

• homozygous thalassemia - can be acquired from both parents, is characterized by the excessive presence of red pigment, and can occur closer to a year after birth and have a number of fairly pronounced symptoms and disorders in the child’s body;
• heterozygous thalassemia - has another name - thalassemia minor, which is the result of the transfer of pathology from one of the parents; in this case, signs of anemia are practically not expressed in the child, and symptomatic signs and disorders are completely absent.

The division of this disease described above occurs only in the case of the classic variant of thalassemia. Violations of this division of thalassemia cannot be ruled out. In any case, the patient needs urgent consultation with a specialist, further examination and immediate effective treatment of the disease.

Causes

What kind of disease is thalassemia and what are its main causes? The main cause of thalassemia among patients is considered to be the manifestation of mutations in the DNA of cells responsible for hemoglobin levels. As a result, a disruption in the normal performance of this substance may occur, which ultimately leads to the occurrence of a hemolytic process - anemia or anemia in the child.

As mentioned earlier, the process of transmission of the disease occurs from parents to children.

In addition, the causes of the disease include:

• synthesis of abnormal messenger RNA;
• deletion of structural genes;
• mutations of regulatory genes;
• inefficient gene transcription.

All these reasons contribute to gradual bone marrow hyperplasia, which entails deformation of the bone tissue of the patient’s skeleton. Such violations negatively affect the further development of the child, especially his growth.

Symptomatic signs

All obvious signs of thalassemia disease directly depend on the severity of the disease itself and on the age characteristics of the patient. The most common symptoms of the disease in a child include:

• constant feeling of fatigue even after a long rest;
• the presence of a feeling of weakness throughout the body (the reason for this is a decrease in hemoglobin levels);
• violation of the correct shape of the facial skeleton;
• difficulty or complete stop of general development (mainly its slow progress);
• the occurrence of flatulence due to excessive accumulation of gases;
• change in the appearance of urine (it becomes dark brown).

Each type of disease such as thalassemia is characterized by its own specific symptoms, which are presented in more detail in the table:

As for the functionality of internal organs, many patients may exhibit an enlarged liver and spleen, which is actively affected by the impaired type of hematopoiesis. The protective function of the child’s body decreases, which entails the constant transfer of various infectious and viral diseases by the little patient. The disease thalassemia and its symptoms are individual in nature.

Diagnostic measures

Diagnosis of the disease in patients is carried out by conducting certain studies, the main of which include:

• bone marrow study;
• hemoglobin electrophoresis;
• taking a blood test to determine hemoglobin levels.

In most cases, with thalassemia, it is enough for the patient to undergo a general blood test, the results of which may already indicate the presence of a pathological process and a violation of the child’s health.

A comprehensive prenatal examination should be carried out at 11 weeks of pregnancy. To do this, a fragment of the placenta is taken, and the infection of the fetus with thalassemia is determined by studying the amniotic fluid at approximately 16 weeks.

To do this, specialists use a special needle, and with this needle they take a sample for further study.

Currently, the latest technology for preimplant genetic diagnosis of thalassemia is particularly popular. This method allows the mother to give birth to a healthy child in the future. Since the main diagnosis is a laboratory study of tests, it makes sense to pay attention to the interpretation of the results obtained and what are the deviations from the norm in the main indicators:

• when studying blood, the hemoglobin level decreases to common limits - 50-30 g/l;
• the disappointing color indicator as a result of calculations varies within 0.5 and below;
• red blood cells have changed sizes;
• blood cell resistance is clearly increased;
• the number of reticulocytes significantly exceeds normal values.

Bilirubin is also changed for the worse, which in turn indicates an excessive amount of iron present. Such disorders can provoke the occurrence of parallel diseases - liver cirrhosis and the development of diabetes mellitus. In some cases, damage to cardiac functionality is possible.

Main methods of treatment

Thalassemia disease requires complex treatment, which makes it possible to prevent its further progression. In this case, the treatment of thalassemia has its own specific features. The detection of this oxygen deficiency at the cellular level indicates that the patient needs an emergency blood transfusion. At the initial stages of treatment of the disease, this patient requires about 10 transfusions. This method is extremely necessary to restore the level of hemoglobin in the blood to normal levels. Subsequently, the total number of transfusions is reduced, but the hemoglobin level is carefully monitored.

This method of treating thalassemia is aimed at:

• improvement of the patient’s general condition;
• eliminating the possible harmful effects of the disease on the skeletal system;
• increasing and strengthening the immune system;
• preventing further enlargement of the spleen;
• favorable development of the child.

It is especially important for specialists to remove excess iron from the body during treatment. In this case, intramuscular injections of Desferal are prescribed, especially in combination with vitamin C. Often, in order to permanently improve the general health of the patient, surgical treatment for the purpose of bone marrow transplantation may be indicated.

However, there are difficulties here, for example, with the selection of a donor and the subsequent recovery period after surgical treatment.

The most common and effective treatments for Thalassemia include:

1. Red blood cell transfusion. This is especially important when diagnosing a severe form of the disease. Over time, the patient begins to develop so-called transfusion dependence. This reaction of the body is characterized by a stable decrease in hemoglobin. This may threaten the patient’s life or the disease will begin to actively progress. This procedure has its significant drawbacks. In this case, problems may arise with finding the most suitable donor, since careful individual selection is required.
2. Splenectomy. This procedure is called splenectomy, and the method is considered necessary due to the effect of an enlarged organ on hemoglobin levels. Thus, elimination of this internal organ may affect the course of the disease. The operation can only be performed upon reaching 8 years of age. However, this also has its drawbacks, since liver enlargement can be caused. The decision to remove an organ should be taken with extreme caution.
3. Bone marrow transplantation. It is considered one of the radical methods of therapy. It is important to conduct a biological study of all family members for compatibility. This will make it possible to find a more suitable donor. In addition, this procedure has a relatively high cost.

Thalassemia and treatment using genetic engineering are no less popular in eliminating the disease. In this case, it is important to adhere to a specially selected diet (table No. 5), drink drinks that contain tannin, for example, tea or cocoa. To maintain liver functionality, the patient may be prescribed medications - hepatoprotectors: lipoic acid, vitamin E, Essentiale, as well as a course of choleretic herbs - mint, barberry and tubazhi.

There are also treatments for other forms of thalassemia, such as thalassemia intermedia. In this case, the patient does not require constant blood transfusions; one can limit oneself to only single procedures that are carried out in the interval from several weeks to several months.

To summarize all of the above, it should be noted that a disease such as thalassemia can only be completely eliminated in isolated cases, provided that it is diagnosed in the early stages of development. It is important to carry out the necessary treatment in order to prevent possible complications and prolong the patient’s life.

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Often children can inherit from their parents not only characteristic traits and positive qualities, but also a hereditary disease.

The likelihood of getting any hereditary disease depends directly on the presence of defective genes in the parents. Thalassemia refers specifically to such genetic diseases that are inherited from parents to their children.

What is thalassemia

Thalassemia is a group of genetic blood diseases (ICD 10 code – D56), which causes an abnormal mutation of red blood cells, resulting in a disruption in the transport of oxygen molecules to the cells and tissues of the body.

Hemoglobin makes up the bulk of the blood cell and is the main substance for binding oxygen molecules and moving them throughout the body. With this disease, the entire process of synthesis of hemoglobin polypeptide chains is disrupted, which leads to defective and short-lived red blood cells.

As a result of such changes, there is a lack of oxygen in the tissues of the body, which leads to pathology and deterioration in the functionality of human organs.

The carriers of this disease are defective genes that are responsible for the construction of hemoglobin. Their inferiority lies in the impossibility of compiling the correct set of amino acids in the chromosomal chain.

Forms of thalassemia

Polypeptide chains are responsible for the performance of hemoglobin: alpha (α) and beta (β). Impaired synthesis in any of these chains can result in abnormal red blood cells.

There are two types of this disease based on the irregular abnormality of the polypeptide chains:

1. alpha thalassemia (ICD 10 code – D56.0);
2. beta thalassemia (ICD 10 code – D56.1).

And also any type of thalassemia may differ in the way the mutant gene is acquired from the parents. Heterozygous thalassemia is acquired from only one parent and is usually a mild form of the disease. Homozygous thalassemia is acquired from both parents and can have a moderate or severe form of the disease.

Alpha thalassemia

Four genes (two genes from each parent) are responsible for building the alpha chain.

The severity of thalassemia disease will depend on the number of transmitted “sick” genes:

1. Mutation in one gene. The disease is not detected due to the absence of clinical manifestations. A person with this form of thalassemia can only be a carrier, which will lead to the likelihood of transmitting the disease to their children in the future.
2. Mutation in two genes. Thalassemia minor is characterized by a low level of hemoglobin in the blood and small red blood cells. May be acquired from one or both parents.
3. Mutation in three genes. The average form of the disease has a clear violation of the oxygen supply of the body. Various pathologies can occur in the systems and organs of the human body.
4. Mutation in four genes. Major form of the disease or alpha thalassemia major. With this anomaly, the alpha chains responsible for the transfer of oxygen molecules into cells are completely absent. This form of the disease leads to the death of the child in the womb or in the first days after birth.

Beta thalassemia

Only two genes (one from each parent) are involved in creating the beta chain in hemoglobin. When a mutation occurs in one or two genes of this chain, beta thalassemia appears.

There are three forms of this type of disease:

1. Minor or minor form of thalassemia occurs when there is a single mutant gene. It is characterized by a subtle decrease in beta chains, which affects the absence of external signs of the disease.
   For blood tests small red blood cells are detected. A person with this form of the disease lives a relatively healthy life.
2. Intermedia or thalassemia intermediate form is formed by a slight mutation of two genes. Significant damage to the beta chains occurs, which affects very low hemoglobin levels and the presence of a large number of underdeveloped red blood cells. Without treatment, the moderate form usually becomes severe.
3. Major or major form of thalassemia(Cooley's anemia) occurs with a complete mutation of both genes responsible for beta chains. This form requires constant blood transfusions to maintain hemoglobin levels.

Symptoms

In forms of thalassemia minor and major, symptoms manifest differently. According to the method of acquisition, thalassemia minor is classified as heterozygous, that is, the thalassemia gene is transmitted from one parent. In this case, due to the healthy gene from the second parent, the entire overall picture of the disease will be slightly noticeable.

The main symptoms of the minor form include:

• general fatigue, lethargy and weakness;
• frequent headaches and dizziness;
• pallor and yellowness of the skin;
• accumulation of gases, flatulence;
• high susceptibility to viral and intestinal infections;
• possible enlargement of the spleen and liver upon palpation and ultrasound diagnostics.

Moderate and severe forms of thalassemia are classified as homozygous, since defective genes are received from the father and mother at once.

Symptoms for these forms of the disease are pronounced:

• tower-shaped skull;
• formation of Mongoloid facial features;
• enlargement of the upper jaw and expansion of the nasal septum throughout the course of the disease;
• yellowness and pallor of the skin. Also read our article about.
• mental and physical developmental delays are observed;
• formation of bone growths on the feet;
• enlargement of the spleen and liver due to lack of oxygen;

Children with severe thalassemia rarely exceed the five-year mark.

During the transition to adolescence, patients experience additional symptoms:

• frequent bone fractures;
• frequent lung infections;
• sepsis due to contact with infection
• delayed sexual development.

Diagnostics

Modern medicine is able to diagnose this blood disease in the early stages if the diagnosis is carried out correctly.

The first step is timely genetic consultation before planning pregnancy to determine the heredity of thalassemia in future parents. Prenatal diagnosis is possible as early as the eleventh week of pregnancy. Early detection of the disease will help to begin to fight thalassemia in advance.

Sometimes a family history and external examination of the patient allows one to suspect a blood disease in the early stages.

To confirm the diagnosis and begin treatment, the following tests are prescribed for thalassemia:

1. general blood test - checks the level of hemoglobin, the size and shape of red blood cells, the presence of reticulocytes.
2. blood biochemistry - checking bilirubin levels, iron concentration, ability to bind iron.
3. PCR – detection of a defective thalassemia gene in the chromosome. Allows you to definitively confirm or reject the diagnosis of thalassemia.
4. Ultrasound diagnostics - the size of the liver, spleen and the presence of bilirubin stones are examined.
5. bone marrow puncture - the composition and nature of the malfunction of the hematopoietic system.
6. X-ray examination - detection of defects of the skeleton and bone tissue.
7. specific blood tests to determine damage to the circulatory system.

Causes of the disease

• Thalassemia is the most complex hereditary disease, since it is transmitted from parents to children through defective genes that have undergone mutation. Sometimes parents, being carriers, may not be aware of the existence of this disease in their blood. But thalassemia can fully manifest itself in the genes passed on to children.
• If you have the wrong genes hemoglobin synthesis is disrupted in chromosomes, which leads to loss of functionality of red blood cells.
• Foci of spread This disease occurs mainly in the Mediterranean, the Middle East and Central Africa, and is extremely rare in Latin America.
• Occurrence of a primary mutation parent gene is due to Plasmodium falciparum. It has been scientifically proven that it is Plasmodium, when it enters the human blood, that has the main influence on the mutation of genes in the sixteenth and eleventh pairs of chromosomes, which are responsible for the creation of alpha and beta chains.

Treatment

Thalassemia is still one of the rare treatable diseases. This is primarily due to the poor effectiveness and complexity of the treatment method.

With thalassemia minor, no special treatment is required, but there is an action plan to maintain the patient’s moderate condition:

1. Regular collection of blood tests to monitor hemoglobin, red blood cells and iron.
2. Compliance with the recommended lifestyle and nutrition.
3. Reducing iron levels in the human body using food and medicine.

For moderate and major forms of thalassemia, a number of treatment measures are being developed:

What is the danger of the disease

1. In a mild form of this disease the patient is exposed to minimal danger. Since the disease is practically asymptomatic and does not have serious consequences. The only danger is the subsequent transmission of the abnormal thalassemia gene to a future generation.
2. For thalassemia major There is a high mortality rate, especially among newborn patients. In mature and adolescent patients, there is a risk of developing additional serious diseases such as cancer, sepsis, and infections.

Thalassemia prognosis

For patients with thalassemia, the prognosis depends on the severity of the disease:

• With thalassemia minor people often live full, long lives. The difference between such a patient and a healthy person is weaker immunity to various infections.
• Patients with severe thalassemia have a separate way of life. In newborns with this disease, all symptoms appear in the second year of life. People with thalassemia require regular blood transfusions to keep the body functioning. Often the consequences of thalassemia are diabetes, liver cirrhosis, myocardial infarction, and severe joint diseases.
• When appearing in a family history This disease poses a risk of further spread and infection of thalassemia in all subsequent generations.

Prevention

The main goal of prevention is to identify the risk factor for inheriting thalassemia.

There is a set of measures aimed at preventing and preventing this disease:

1. Prenatal diagnostics and genetic consultation, which identify the predisposition of parents and the unborn child.
2. Prenatal diagnosis. It is carried out when an abnormal gene is detected in one or both parents. Sometimes the result of such a diagnosis can be a planned termination of pregnancy.
3. Constant monitoring of patients diagnosed with thalassemia by geneticists, hematologists and therapists.
4. Patients with thalassemia are required to constantly follow a regimen that helps avoid infections.

Every person who does not know his family history is required to undergo a genetic test in advance to detect thalassemia in the blood. It is important to know that this disease is not acquired during life, the child is already born with thalassemia in his genes.