Thalassemia

Thalassemia is a genetic blood disorder characterized by the body’s inability to produce adequate amounts of hemoglobin, the protein in red blood cells responsible for transporting oxygen throughout the body. The disorder leads to anemia, a condition where the body lacks enough healthy red blood cells to function properly. Thalassemia can range from mild to severe and can significantly affect a person’s quality of life. It is especially prevalent in parts of the Mediterranean, Middle East, South Asia, and Africa.

In this comprehensive guide, we will explore the different types of thalassemia, the underlying causes, symptoms, diagnostic procedures, and available treatments, providing a detailed understanding of this complex condition.

What Is Thalassemia?

It is an inherited blood disorder, meaning it is passed down from parents to their children through their genes. It primarily affects the production of hemoglobin, the protein in red blood cells that carries oxygen to different parts of the body. Hemoglobin is made up of two parts: alpha and beta chains. Based on the defect in these chains, thalassemia is classified into two main types:

1. Alpha: In this type, the body has trouble producing alpha chains.
2. Beta: This type involves a problem in the production of beta chains.

A deficiency in either of these chains results in inadequate or malfunctioning hemoglobin, leading to reduced oxygen levels in the body and, consequently, anemia. The severity of thalassemia depends on how many defective genes a person inherits and which type of thalassemia they have.

Types

Thalassemia comes in different forms, ranging from mild to severe. The specific type a person has depends on which part of the hemoglobin molecule is affected (alpha or beta) and how many gene mutations are involved. Let’s look at the two main categories of thalassemia and their subtypes.

1. Alpha Thalassemia

In alpha thalassemia, there is a defect in the alpha globin genes, which are responsible for producing the alpha part of hemoglobin. A person inherits four genes (two from each parent) that produce alpha globin, and the severity of alpha thalassemia depends on how many of these genes are mutated or missing.

• Silent Carrier State: This occurs when one of the four alpha globin genes is missing or mutated. People with this condition usually have no symptoms and are said to be silent carriers. They do not have anemia but can pass the defective gene to their offspring.
• Alpha Thalassemia Trait (Minor): This happens when two of the four alpha globin genes are affected. People with alpha thalassemia trait may have mild anemia but usually do not require treatment. They may, however, pass the gene to their children.
• Hemoglobin H Disease: This condition occurs when three of the four alpha globin genes are missing or defective. Hemoglobin H disease results in moderate to severe anemia, and affected individuals may require blood transfusions and other treatments to manage the symptoms.
• Alpha Thalassemia Major (Hydrops Fetalis): This is the most severe form of alpha thalassemia and occurs when all four alpha globin genes are defective. Babies with this condition usually do not survive long after birth or may be stillborn, as they cannot produce enough hemoglobin to sustain life.

2. Beta Thalassemia

In beta thalassemia, the body has trouble producing the beta chains of hemoglobin. A person inherits two beta globin genes (one from each parent), and the severity of the condition depends on whether one or both genes are affected.

• Beta Thalassemia Minor: Also known as beta thalassemia trait, this condition occurs when one of the beta globin genes is defective. People with beta thalassemia minor may have mild anemia but typically do not require treatment. They are, however, carriers of the gene and can pass it on to their children.
• Beta Thalassemia Intermedia: This is a more severe form of the condition, where both beta globin genes are affected, but they still produce some functional hemoglobin. People with beta thalassemia intermedia have moderate anemia and may require blood transfusions, especially during times of stress or illness.
• Beta Thalassemia Major (Cooley’s Anemia): This is the most severe form of beta thalassemia and occurs when both beta globin genes are severely mutated, resulting in very little or no hemoglobin production. Babies born with beta thalassemia major usually develop severe anemia within the first two years of life and require lifelong regular blood transfusions and medical care.

Causes

Thalassemia is caused by mutations in the genes that control hemoglobin production. These mutations are inherited from one or both parents. The type a person has depends on the specific gene mutations they inherit.

1. Alpha Thalassemia is caused by mutations or deletions in the HBA1 and HBA2 genes, which are responsible for the production of alpha globin.
2. Beta Thalassemia is caused by mutations in the HBB gene, which affects the production of beta globin.

Thalassemia is passed down in an autosomal recessive pattern, which means both parents must be carriers of the mutated gene for their child to develop the disease. If only one parent passes on the defective gene, the child will become a carrier but may not show symptoms (or only experience mild symptoms).

It is more common in individuals of Mediterranean, Middle Eastern, South Asian, and African descent, likely due to a historical survival advantage against malaria.

The Importance of Pre-Marriage Health Check-Up:

Pre-marriage health check-ups are a critical aspect of responsible family planning and can be particularly important when it comes to the risk of inherited genetic conditions like thalassemia. Here are some key reasons why pre-marriage health check-ups are important:

1. Risk Assessment: It is an autosomal recessive genetic disorder, which means that both parents must carry the mutated gene for there to be a risk of having a child with thalassemia major, the severe form of the condition. Pre-marriage health check-ups can assess whether both partners are carriers of the thalassemia gene, helping to determine the risk of having an affected child.
2. Informed Decision-Making: Knowledge is power. Knowing your thalassemia carrier status enables couples to make informed decisions about their future and family planning. They can understand the potential risks and options available to them, which may include genetic counseling, prenatal testing, or considering other family planning strategies.
3. Prevention: If both partners are identified as carriers of the thalassemia gene, they can take steps to prevent the birth of a child with thalassemia major. This may involve exploring alternatives such as adoption, in vitro fertilization with pre-implantation genetic diagnosis, or the use of donor eggs or sperm.
4. Reducing the Burden: Thalassemia major is a lifelong, debilitating condition that requires ongoing medical care, including regular blood transfusions and chelation therapy. By identifying carrier status in prospective parents, pre-marriage health check-ups can help reduce the number of individuals born with thalassemia major and, in turn, lessen the burden on healthcare systems and families.
5. Emotional and Psychological Well-Being: Learning about a genetic risk before marriage can help prevent emotional and psychological distress that might arise if a child is born with a severe genetic condition. It can also facilitate open and supportive communication between partners about their family planning options.
6. Community Awareness: Promoting pre-marriage health check-ups for thalassemia raises awareness about the condition and the importance of genetic testing. It encourages individuals and couples to take proactive steps to ensure the health and well-being of their future children.

Thalassemia symptoms

The symptoms can vary depending on the type and severity of the condition. In mild cases, there may be few or no noticeable symptoms, while in severe cases, symptoms can be life-threatening.

Common symptoms include:

• Fatigue: Due to anemia, the body does not receive enough oxygen, leading to chronic fatigue and weakness.
• Paleness: Reduced red blood cell count leads to pale skin, especially around the face, lips, and inside the mouth.
• Shortness of breath: Low oxygen levels can cause difficulty breathing, particularly during physical activity.
• Delayed growth and development: Children with severe thalassemia may experience stunted growth and delayed puberty due to a lack of oxygen and nutrient-rich blood.
• Jaundice: Some people develop yellowing of the skin and eyes, known as jaundice, due to the breakdown of red blood cells.
• Bone deformities: In some cases, the body attempts to produce more red blood cells in the bone marrow, which can lead to the expansion of the bone marrow and cause deformities, particularly in the face and skull.
• Enlarged spleen: The spleen filters abnormal red blood cells, and over time, it can become enlarged, leading to abdominal discomfort and additional complications.
• Dark urine: The breakdown of red blood cells can result in darker-colored urine.

In severe cases like beta thalassemia major, additional symptoms can include heart complications, liver disease, and a higher risk of infections due to frequent blood transfusions.

Diagnosis

Diagnosing thalassemia involves a combination of blood tests, genetic tests, and a thorough medical history. In some cases, prenatal testing may be done to identify the condition before birth.

Common diagnostic procedures include:

1. Complete Blood Count (CBC): This test measures the levels of red blood cells, hemoglobin, and other blood components. People with thalassemia typically have low hemoglobin levels and smaller-than-normal red blood cells (microcytosis).
2. Hemoglobin Electrophoresis: This test is used to identify abnormal forms of hemoglobin and can help differentiate between thalassemia and other types of anemia, such as sickle cell anemia.
3. Genetic Testing: DNA analysis can be used to detect mutations in the HBA1, HBA2, and HBB genes, confirming a diagnosis of alpha or beta thalassemia.
4. Prenatal Testing: For couples at risk of having a child with thalassemia, prenatal testing options such as chorionic villus sampling (CVS) or amniocentesis can be used to detect the condition in the developing fetus.
5. Peripheral Blood Smear: This test allows doctors to examine the shape and size of red blood cells under a microscope, which can provide clues about the presence of thalassemia.

Thalassemia treatment

The treatment depends on the severity of the condition. While there is no cure for thalassemia (except in some cases of bone marrow transplantation), treatment options aim to manage symptoms, prevent complications, and improve quality of life.

1. Blood Transfusions

For individuals with moderate to severe thalassemia, regular blood transfusions are the mainstay of treatment. Blood transfusions provide the patient with healthy red blood cells, allowing the body to receive enough oxygen. However, frequent transfusions can lead to a buildup of iron in the body, requiring additional treatments to remove the excess iron.

2. Iron Chelation Therapy

Because frequent blood transfusions can lead to iron overload, patients with thalassemia often need iron chelation therapy. This involves using medications, such as deferoxamine or deferasirox, to remove excess iron from the body and prevent complications like heart and liver damage.

3. Folic Acid Supplements

Folic acid is essential for the production of red blood cells. Many people with thalassemia are prescribed folic acid supplements to help their bodies produce more red blood cells and improve anemia symptoms.

4. Bone Marrow or Stem Cell Transplantation

In severe cases, a bone marrow or stem cell transplant may be considered as a potential cure. This procedure involves replacing the patient’s faulty bone marrow with healthy bone marrow from a donor. However, this treatment is only suitable for certain patients, and finding a compatible donor can be challenging.

5. Gene Therapy

Gene therapy is a promising area of research in the treatment of thalassemia. Scientists are exploring ways to introduce healthy copies of the defective gene into the patient’s stem cells to restore normal hemoglobin production. While gene therapy is still experimental, it holds great potential for the future treatment of thalassemia.

Thalassemia is a genetic blood disorder that affects millions of people worldwide, particularly in regions such as the Mediterranean, the Middle East, and South Asia. While there is no universal cure for thalassemia, advances in treatment and care have significantly improved the quality of life for people with the condition. Early diagnosis, regular monitoring, and appropriate treatment can help manage symptoms and prevent complications.

For families affected by thalassemia, genetic counseling is important to understand the risks and make informed decisions about family planning. As research continues, innovative treatments such as gene therapy offer hope for a future where thalassemia can be effectively managed or even cured.

To get tested, call Sparsh Diagnostic Centre’s helpline number 9830117733.

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