UPSC MainsZOOLOGY-PAPER-II202510 Marks150 Words
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Q3.

Write on the following in about 150 words each: 1.(c) Symptoms, causes and treatment of thalassemia

How to Approach

The answer should begin by defining thalassemia as a genetic blood disorder. Then, it needs to systematically cover its causes, symptoms, and treatment. For causes, explain the genetic basis (alpha and beta globin chains). For symptoms, differentiate between mild and severe forms. For treatment, discuss standard interventions like blood transfusions and chelation therapy, as well as curative options like bone marrow transplantation. Emphasize the importance of genetic counseling and screening.

Model Answer

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Introduction

Thalassemia is an inherited genetic blood disorder characterized by the body's inability to produce sufficient amounts of functional hemoglobin, the protein in red blood cells responsible for oxygen transport. This deficiency leads to anemia, ranging from mild to severe, and a host of other health complications. As a monogenic disorder, it represents a significant public health challenge, especially in regions with high carrier prevalence like India, which accounts for approximately 25% of the global beta-thalassemia burden. Understanding its etiology, clinical manifestations, and therapeutic strategies is crucial for effective management and prevention.

Causes of Thalassemia

Thalassemia is caused by inherited genetic mutations or deletions in the genes responsible for producing the globin protein chains (alpha and beta) that constitute hemoglobin. These genetic defects lead to reduced or absent synthesis of either alpha-globin or beta-globin chains, resulting in an imbalance and the formation of abnormal hemoglobin. Thalassemia is broadly classified into two main types:

  • Alpha-Thalassemia: Occurs due to defective genes affecting the alpha-globin chains. Humans inherit four alpha-globin genes (two from each parent). The severity depends on the number of missing or mutated genes.
  • Beta-Thalassemia: Arises from mutations in the genes affecting the beta-globin chains. Humans inherit two beta-globin genes (one from each parent). Beta-thalassemia is further categorized into:
    • Thalassemia Minor (Trait): One mutated gene, usually mild or asymptomatic.
    • Thalassemia Intermedia: Two mutated genes, leading to moderate anemia.
    • Thalassemia Major (Cooley's Anemia): Two severely mutated genes, resulting in severe anemia and life-threatening complications.

Symptoms of Thalassemia

The symptoms of thalassemia vary significantly based on the type and severity of the condition. While carriers (thalassemia minor) might be asymptomatic, individuals with more severe forms experience a range of symptoms:

  • Common Symptoms (Mild to Moderate):
    • Fatigue, weakness, shortness of breath due to anemia.
    • Pale or yellowish skin (jaundice).
    • Delayed growth and puberty.
    • Bone abnormalities, including osteoporosis and changes in facial structure (e.g., enlarged forehead, prominent cheekbones).
    • Enlarged spleen and liver (hepatosplenomegaly).
    • Dark urine.
  • Severe Symptoms (Thalassemia Major):
    • Severe, chronic anemia requiring frequent blood transfusions.
    • Poor appetite.
    • Increased susceptibility to infections.
    • Serious organ damage due to iron overload (heart, liver, endocrine glands) if not managed.
    • High risk of cardiac complications and premature death if untreated.

Treatment of Thalassemia

Treatment strategies depend on the type and severity of thalassemia, aiming to manage symptoms and prevent complications.

Treatment Type Description Purpose
Blood Transfusions Regular transfusions of healthy red blood cells, often every few weeks for severe forms. To combat severe anemia and maintain adequate hemoglobin levels.
Iron Chelation Therapy Medications (e.g., deferoxamine, deferasirox) to remove excess iron. To prevent iron overload from frequent transfusions, which can damage vital organs like the heart and liver.
Folic Acid Supplements Oral supplements of folic acid. To support red blood cell production.
Bone Marrow Transplant (BMT) / Hematopoietic Stem Cell Transplantation (HSCT) Infusion of healthy stem cells from a compatible donor (usually a matched sibling). Currently the only potential cure for thalassemia, particularly effective in younger patients. However, it carries significant risks like graft-versus-host disease.
Genetic Counseling & Prenatal Diagnosis Counseling for carriers on inheritance risks and prenatal testing. To inform family planning decisions and prevent the birth of affected children.
Splenectomy Surgical removal of the spleen. Considered in cases of severe splenomegaly that contributes to increased red blood cell destruction.

Conclusion

Thalassemia is a complex genetic disorder with varied clinical presentations, necessitating comprehensive management tailored to individual severity. While advancements in blood transfusions and iron chelation therapy have significantly improved the life expectancy and quality of life for patients, bone marrow transplantation remains the only definitive cure. Given its hereditary nature, robust public health initiatives focusing on awareness, pre-marital and prenatal screening, and genetic counseling are paramount to reducing the disease burden, particularly in high-prevalence areas. Continued research into gene therapy offers future hope for more effective and less invasive cures.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Hemoglobin
A protein found in red blood cells that is responsible for carrying oxygen from the lungs to all parts of the body and transporting carbon dioxide back to the lungs.
Iron Chelation Therapy
A medical treatment used to remove excess iron from the body. It is crucial for thalassemia patients who receive frequent blood transfusions, as these can lead to harmful iron accumulation in organs.

Key Statistics

India has the highest number of children with thalassemia major globally, estimated to be between 100,000 to 150,000. Approximately 10,000 to 15,000 children with thalassemia major are born each year in India. (Source: Drishti IAS, 2024; IndiaToday.In, 2024)

The prevalence of beta-thalassemia carriers in India ranges from 2.9% to 4.6%, with approximately 30 million Indians being silent carriers. (Source: PIB, 2022; ResearchGate, 2023)

Examples

Cooley's Anemia

Thalassemia Major is often referred to as Cooley's Anemia, named after Dr. Thomas Cooley, who first described the severe form of beta-thalassemia in children in 1925. This form is characterized by profound anemia and requires lifelong blood transfusions.

Genetic Counseling for Prevention

In communities with a high prevalence of thalassemia carriers, like certain groups in the Mediterranean, Middle East, and South Asia, genetic counseling combined with pre-marital or prenatal screening programs has significantly reduced the incidence of thalassemia major births by informing couples about their risks and reproductive options.

Frequently Asked Questions

Is thalassemia contagious?

No, thalassemia is not contagious. It is an inherited genetic disorder, meaning it is passed down from parents to their children through genes.

Topics Covered

Human PhysiologyGeneticsGenetic DisordersHemoglobinopathies