What Are the Types and Causes of Thalassemia?
Thalassemia is a blood disorder, which comes hereditary and results in the reduction of hemoglobin. Since it is hereditary it is a genetic disorder, which is inherited from a parent to the child. Alpha thalassemia and beta-thalassemia are the two types of thalassemia. For Alpha globin, the severity of the Thalassemia depends on how many of the four genes are missing, and for Beta globin, the severity is dependent on how many of the two genes are missing. It can typically be diagnosed by the common blood test (CBC).
Thalassemia could be a heterogeneous group of autosomal recessive genetic disorders characterized by the decreased or absent synthesis of globin chains, resulting in anemia and microcytosis.
What is Thalassemia?
Thalassemia is a genetic blood disorder and in which the body does not make hemoglobin, a protein found in the red blood cell which carries the oxygen. If the hemoglobin count drops it may result in severe conditions. If hemoglobin count drops, red blood cells may not function properly and last for a shorter period of time, and hence the number of healthy red blood cells traveling in the bloodstream also decreases. Since Haemoglobin carries oxygen, it works as food to the cells, and due to the decrease of Haemoglobin in the body, the cells do not get their food and hence it results in weakness, fatigue, or shortness of breath. These are the main symptoms of Anaemia, and people who have thalassemia may suffer from either mild or severe anemia. Thalassemia only passes to the child when either one or both the parents carry the disorder. It is caused by the abnormalities of key genes fragments.
Thalassemia minor could be a less severe variety of the disease. There are two primary varieties of thalassemia that are more serious. In alpha thalassemia, a minimum of one among the alpha-globin genes incorporates a mutation or abnormality. The beta-globin genes are affected by beta-thalassemia.
Symptoms of Thalassemia
The severity of the symptoms of Thalassemia depends on the type of Thalassemia with which the patient is suffering. For some people, symptoms start appearing from birth, while for others it may take a few years to be visible. Listed below are the common symptoms of Thalassemia:
Children affected with Thalassemia have slow growth.
Skin colour turns to either pale or yellow.
Loss of appetite or poor appetite.
Fatigue and weakness.
Deformities in Bone.
Dark coloured Urine,
Jaundice.
Swelling in the Abdominal
You can find the answer to some basic questions regarding Thalassemia here Thalassemia and sickle cell anemia are caused due to class 12 biology CBSE (Vedantu).
Chances of Inheriting the Disease
Thalassemia is a genetic disorder that occurs when there is an abnormality or mutation in one of the genes involved in hemoglobin production. If only 1 of your parents may be a carrier for thalassemia, you will develop a variety of diseases referred to as thalassemia minor. If this happens, you most likely will not have symptoms, but you'll be a carrier. Some people develop minor symptoms with thalassemia minor. If both of your parents are carriers of thalassemia, you have got a higher chance of inheriting a more severe type of the disease.
Types of Thalassemia
There are three main sorts of thalassemia.
• Beta-thalassemia, which has the subtypes major and intermedia
• Alpha thalassemia, which includes the subtypes hemoglobin H and hydrops fetalis
• Thalassemia minor
Thalassemia Treatment
The treatment for thalassemia depends on the sort and severity of the disease involved. Your doctor will provide you with a course of treatment that may work best for your particular case. Some of the treatments include:
• Blood transfusions
• Bone marrow transplant
• Medications and supplements
• Possible surgery to get rid of the spleen or gallbladder
Your doctor may instruct you not to take vitamins or supplements containing iron. It can be exactly accurate if you wish for blood transfusions because those who receive them accumulate extra iron that the body cannot quickly eliminate. Iron can build up in tissues, which may be potentially fatal. If you are receiving an intro, you will also need chelation therapy. It generally involves binding with iron and other heavy metals to receive an injection of a chemical. It helps to remove extra iron from your body and make the balance of it.
Beta Thalassemia
Beta thalassemia happens when your body cannot produce beta-globin. Two genes, one from each parent, are inherited to form beta-globin. This sort of thalassemia comes in two severe subtypes: Mediterranean anemia (Cooley's anemia) and thalassemia intermedia.
Thalassemia Major
Thalassemia major is the most severe variety of beta-thalassemia. It develops when beta-globin genes are missing. Thalassemia's major symptoms generally appear before a child's second birthday. The severe anemia associated with this condition is life-threatening. Other signs and symptoms include:
• Fussiness
• Paleness
• Frequent infections
• A poor appetite
• Failure to thrive
• Jaundice, which may be a yellowing of the skin or the whites of the eyes
• Enlarged organs
This form of thalassemia is typically so severe that it requires regular blood transfusions.
Thalassemia Intermedia
Thalassemia intermedia could be a less severe form. It develops thanks to alterations in both beta-globin genes. People with thalassemia intermedia do not need blood transfusions.
Alpha Thalassemia
Alpha thalassemia happens when the body cannot make alpha-globin. To form alpha-globin, you wish to possess four genes, two from each parent. This kind of thalassemia also has two serious types: hemoglobin H disease and hydrops details.
Haemoglobin H
Haemoglobin H develops when an individual is missing three alpha globin genes or experiences changes in these genes. This disease can result in bone issues. The cheeks, forehead, and jaw may all overgrow. Additionally, hemoglobin H disease can cause:
• Jaundice
• An extremely enlarged spleen
• Malnourishment
FAQs on Thalassemia: Definition, Types, Symptoms & Treatment
1. What is the fundamental cause of Thalassemia as per the NCERT syllabus for 2025-26?
Thalassemia is an inherited blood disorder caused by mutations or deletions in the genes responsible for producing haemoglobin. This genetic defect results in a reduced rate of synthesis of one of the globin chains (either alpha or beta) that form the haemoglobin molecule. Consequently, abnormal haemoglobin is produced, leading to the destruction of red blood cells and causing anaemia.
2. What are the main types of Thalassemia and how are they classified?
Thalassemia is primarily classified based on which globin chain of the haemoglobin molecule is affected. The two main types are:
- Alpha-Thalassemia: This type is caused by a defect in the production of the alpha-globin chain. The synthesis of this chain is controlled by two genes (HBA1 and HBA2) on chromosome 16.
- Beta-Thalassemia: This type is caused by a defect in the production of the beta-globin chain. The synthesis of this chain is controlled by a single gene (HBB) on chromosome 11.
3. How does Thalassemia Major differ from Thalassemia Minor?
The main difference between Thalassemia Major and Minor lies in the genetic inheritance and clinical severity:
- Thalassemia Minor: This occurs when an individual inherits one faulty gene from a single parent. They are typically asymptomatic carriers of the disorder, often referred to as having the 'thalassemia trait'.
- Thalassemia Major: This is a severe form of the disease that occurs when a child inherits faulty genes from both parents. Individuals with Thalassemia Major suffer from severe anaemia and require lifelong medical care, including regular blood transfusions.
4. What are the common symptoms a person with Thalassemia might exhibit?
The symptoms of Thalassemia vary depending on its severity. In moderate to severe cases, such as Beta-Thalassemia Major, a person might exhibit fatigue, weakness, pale or yellowish skin (jaundice), slow growth and development, facial bone deformities, dark urine, and an enlarged spleen. Individuals with Thalassemia Minor often have no symptoms at all.
5. How is Thalassemia diagnosed based on standard biological tests?
Thalassemia is diagnosed through a series of blood tests. A Complete Blood Count (CBC) can identify anaemia and note the presence of small, pale red blood cells (microcytic anaemia). The definitive diagnostic test is haemoglobin electrophoresis, a lab technique that separates the different types of haemoglobin in the blood. This test can accurately measure the amount of beta and alpha globin chains, revealing the quantitative deficiency characteristic of Thalassemia.
6. Why is Thalassemia considered a quantitative problem of globin synthesis, while Sickle-cell anaemia is a qualitative one?
This distinction highlights the underlying molecular defect. Thalassemia is a quantitative disorder because the mutation causes a reduced production, or *quantity*, of structurally normal globin chains. In contrast, Sickle-cell anaemia is a qualitative disorder because the mutation results in the production of a structurally abnormal globin chain (Haemoglobin S). The quantity of globin produced may be sufficient, but its *quality* is defective, causing red blood cells to adopt a sickle shape.
7. How is Thalassemia inherited? Explain its pattern as an autosomal recessive disorder.
Thalassemia follows an autosomal recessive inheritance pattern. 'Autosomal' means the gene is on a non-sex chromosome, and 'recessive' means an individual must inherit two copies of the mutated gene (one from each parent) to develop the severe form of the disease (Thalassemia Major). If two carriers (each with one mutated gene) have a child, there is a 25% chance the child will have Thalassemia Major, a 50% chance the child will be a carrier like the parents, and a 25% chance the child will be completely unaffected.
8. What is hydrops fetalis, and why does it occur in the most severe form of alpha-thalassemia?
Hydrops fetalis is a critical condition characterized by the abnormal accumulation of fluid in a foetus. In genetics, it is linked to the most severe form of alpha-thalassemia, where all four alpha-globin genes are deleted or non-functional. This complete lack of alpha-globin chains makes the formation of functional foetal haemoglobin impossible, leading to extreme anaemia, heart failure, and massive fluid buildup in the foetus. This condition is typically fatal before or shortly after birth.
9. Can a person with Thalassemia lead a normal life?
The impact of Thalassemia on a person's life is directly related to its severity. Individuals with Thalassemia Minor generally lead completely normal and healthy lives, often unaware they are carriers. However, for those with Thalassemia Major, life involves significant medical challenges. They require lifelong management, including frequent blood transfusions to treat anaemia and chelation therapy to manage the iron overload that results from transfusions. With disciplined medical care, their quality of life and longevity have greatly improved.
10. Is there a permanent cure for Thalassemia?
Currently, the only widely established permanent cure for Thalassemia is a bone marrow transplant (BMT), also known as a stem cell transplant. This procedure involves replacing the patient's defective blood-forming stem cells with healthy cells from a genetically matched donor. While it offers a cure, BMT is a high-risk procedure and is not an option for everyone. Intensive research into gene therapy is ongoing and shows significant promise as a potential future cure by correcting the faulty gene itself.
