What is Mediterranean Anemia (Beta Thalassemia)?
Mediterranean anemia (Beta Thalassemia) occurs when the body produces less hemoglobin protein than necessary due to a genetic deformation. When hemoglobin, an important building block of red blood cells, is insufficient, red blood cells cannot perform their functions fully and the life span of these cells is shortened. This means that there are fewer healthy red blood cells in the blood. In thalassemia, an insufficiency or disorder develops in the production of one of the globin chains that make up the hemoglobin molecule, whose production is under the control of genes. Whichever of the two globin chains has a defect, the disease is named after it and is classified as alpha or beta thalassemia. Mediterranean anemia is the name given to the beta thalassemia form of the disease. Since red blood cells (hemoglobin) carry the oxygen necessary for the tissues, when there is not enough healthy red blood cells in the blood, problems in oxygen transport to the cells occur and anemia occurs. In this picture, the person may feel tired and weak, and conditions such as shortness of breath may occur. Thalassemia, which is a genetic disease, is different from anemia due to iron deficiency. People with thalassemia may be carriers or patients and may not benefit from standard iron treatments.
What is the Frequency of Thalassemia?
Thalassemia is a disease frequently seen in Mediterranean countries including Turkey. An average of 365,000 thalassemia patients are born each year. While there are approximately 4500 thalassemia patients in Turkey, it is known that 1.300.000 people are carriers of this disease. Mediterranean anemia is one of the most common genetic diseases in Turkey and its carrier prevalence is estimated to be around 2.1%. The incidence of beta thalassemia in Adana and Antalya may reach 13%. The regions where thalassemia is most common in the world are Mediterranean countries, North Africa, the Middle East, India, Central Asia and Southeast Asia.
Inheriting Thalassemia
There are two types of thalassemia that can occur in people. If there is a gene that causes thalassemia in each of the HBB genes from the mother and father, the babies are born with the disease; Children become carriers if only one of the parents inherits the disease-carrying gene. If people are carriers, the person himself does not show symptoms, but continues to carry this disease in his genes. The disease occurs due to defective genes in children in gene transfer. If one of the parents is a carrier, the children to be born are at 50% risk of being carriers. However, since the increase in the carrier rate in the society may increase the risk of two carriers coming together and having a sick child, preventing the transmission of the said genes is one of the important factors in reducing the spread of the disease. If both parents are carriers, there is a chance of 50% carrier, 25% sick and 25% normal birth for the children. Therefore, the screening of this disease in Turkey is included in the scope of the screening tests requested before marriage. The risk is higher in consanguineous marriages or marriages made in the Mediterranean and Southeast regions where the disease is seen at high rates. In families where one of the parents is a carrier, it is possible to have healthy children by detecting healthy embryos before pregnancy so that the babies are born healthy.
Causes of Thalassemia
The disease occurs due to mutations in the HBB genes, which are responsible for the production of beta globin protein, one of the building blocks of red blood cells. In beta globin deficiency, the number of healthy hemoglobin in the blood decreases, and in this case, blood cells cannot develop normally. In the absence of healthy blood cells, anemia and other related complications occur.
What Are the Types of Mediterranean Anemia?
Mediterranean anemia has four different clinical courses. These are classified as thalassemia minima (carrier), thalassemia minor (carrier), thalassemia intermedia (moderately severely ill), and thalassemia major (severely ill).
What Are the Types of Mediterranean Anemia?
Mediterranean anemia has four different clinical courses. These are classified as thalassemia minima (carrier), thalassemia minor (carrier), thalassemia intermedia (moderately severely ill), and thalassemia major (severely ill).
Thalassemia Minima (Silent carrier)
These people are in the carrier group. These patients, who do not have any complaints other than mild anemia, are difficult to detect with screening tests, unlike thalassemia minor patients. These people can only be diagnosed with gene analysis.
Thalassemia minor (Carrier)
Like thalassemia minima, this group is also the carrier group. However, these individuals may show signs of anemia. In some cases, the hemograms of these people can be compared to iron deficiency anemia. Therefore, additional scans may be required.
Thalassemia Intermedia
It is the name given to moderately severe cases. In these people, both parents are carriers. Inherited beta globin genes are damaged, but the gene damage is not high enough to cause thalassemia major. In this case, patients experience anemia, but blood transfusion is not considered necessary, as is usually the case in thalassemia major patients. In these patients, thalassemia may not be detected until adulthood in some cases. However, some patients may experience major thalassemia-like symptoms (growth retardation, severe anemia) and may require blood transfusion.
Thalassemia major
It is the most severe type of thalassemia. Both of the genes passed from the parents are damaged. Symptoms begin to appear between the ages of 4 and 12 months, and the diagnosis is usually made during this period.
How Is The Disease Diagnosed? What are the symptoms?
It can be easily detected by disease screening tests. Especially in families with a history of the disease, screening tests must be done. Apart from this, in case of carriers, the disease can be detected when people apply to the hospital with symptoms of anemia. In thalassemia major, the symptoms appear in infancy and take place in a wider spectrum. anemia, weakness, pale skin; jaundice, loss of appetite, abdominal swelling caused by enlarged liver or spleen; enlargement and thinning of the bones, flattening of the nasal root, prominent forehead and other facial bones, and growth retardation are among the symptoms that facilitate diagnosis, especially in children. In the presence of this picture, complete blood count, hemoglobin electrophesis and genetic screening are performed for parents and children. In cases of intermedia, various symptoms may occur in childhood or adulthood, but the disease progresses milder. Moderate anemia, slow growth and bone deformity can also be seen in these people. Anemia is mild in carriers and other symptoms are not seen. These people can continue their lives without the need for any treatment. The degree of the disease may vary depending on which part of the hemoglobin molecule is affected.
Mediterranean Anemia Treatment
While carriers do not need treatment most of the time, patients with thalassemia major need lifelong treatment. Thalassemia treatment is a very expensive treatment. These patients need blood supply every 3 or 4 weeks. However, blood transfusion to patients to eliminate anemia can lead to iron accumulation in the body and, therefore, to various complications. Organs such as the heart, liver, thyroid, parathyroid, pancreas and spleen may be damaged during this treatment; heart failure, diabetes, developmental disorders or hormonal imbalances may occur. Three basic treatment methods are used in moderate and severe thalassemia cases. Chief among these are blood transfusions for patients with major thalassemia. In order to prevent iron accumulation in blood transfusion, chelation therapy is applied. The third treatment method is stem cell therapy with stem cells from a suitable donor. Gene transplantation, which is an innovative treatment, has not yet entered the application phase.
Blood transfusion
In cases of thalassemia major, a blood transfusion is needed every 3 or 4 weeks because the body does not have enough healthy blood cells due to the disease. This treatment is used in combination with chelation therapy, as it can lead to iron accumulation over time and cause organ damage. These patients are also given folic acid supplementation. Patients receiving regular blood transfusions should be kept under constant control due to the possibility of organ damage. In some cases, removal of a patient's spleen can reduce complications. In addition, tests for blood-borne diseases and hepatitis vaccinations need to be done regularly. It is also important for these people to avoid eating foods rich in iron.
Chelation therapy
The purpose of chelation therapy is to clear the accumulated iron from the blood. There is a risk of losing patients if this treatment is not applied. While there may be accumulation after regular blood transfusion in thalassemia patients, accumulation may also occur in patients who do not receive regular transfusions. It can be prevented by various drugs taken by mouth or by subcutaneous infusion.
Stem cell therapy
This treatment method, also known as bone marrow treatment, is suitable for some childhood thalassemia major patients. The transplanted stem cells are able to produce hemoglobin and thus a full recovery can be achieved in the patients. Repair is possible as a result of transferring the stem cells taken from a donor with healthy and suitable tissues such as siblings to the patient. For tissue compatibility, certain tests should be performed before the treatment and liver damage should not develop in the patients who will be transplanted. However, it may not be a complete success in every patient.