SICKLE CELL ANEMIA

Source: Hindu

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Context

• India is making significant strides towards developing a gene therapy for sickle cell anemia, a genetic blood disorder with a high prevalence among the Scheduled Tribes.
• The initiative involves cutting-edge research and extensive ground-level efforts to screen and manage the disease

Details

• Mission 2047: Part of India's long-term vision to eradicate sickle cell disease by the centennial year of independence.

Gene Therapy Using CRISPR-Cas9

• Technology: CRISPR-Cas9, a gene-editing tool, is being used to develop a gene therapy for sickle cell anemia.
• Progress: The Union Tribal Affairs Ministry, in collaboration with AIIMS and CSIR-IGIB, is conducting laboratory tests, with promising results expected by January 2025.
• Potential: This gene therapy could be a single-dose cure, revolutionizing the treatment of sickle cell anemia in India.

Implementation Strategy

Ground-Level Healthcare Workers

• ASHAs and Anganwadi Workers: These workers are essential for screening and managing sickle cell disease at the community level.
• Training and Coordination: The Tribal Affairs Ministry aims to train these workers to effectively implement the screening and management programs.

Screening and Awareness

• National Conclave: Organized by the Tribal Affairs Ministry and AIIMS to raise awareness and discuss strategies for sickle cell disease management.
• Screening Goal: The mission includes conducting over seven crore screenings across 17 States and Union Territories, with three crore screenings already completed.

Challenges and Goals

Cost-Effectiveness

• Affordability: Making the CRISPR-Cas9 gene therapy affordable is a primary challenge.
• Government Dossier: The mission to eradicate sickle cell disease by 2047 includes making advanced treatments accessible to all affected populations.

Integration of Healthcare Services

• Multidisciplinary Approach: Collaboration between various ministries and departments to ensure comprehensive care and management.
• Engagement: Senior officials emphasize the need for direct engagement with grassroots healthcare workers to ensure successful implementation.

Sickle Cell Anemia

• Sickle cell anemia is a hereditary blood disorder characterized by the production of abnormal hemoglobin, called hemoglobin S or sickle hemoglobin.
• This causes red blood cells to become rigid and shaped like a crescent or sickle.

Causes and Genetics

• Genetic Basis: Caused by a mutation in the HBB gene, which encodes the beta-globin subunit of hemoglobin.
• Inheritance Pattern: Autosomal recessive. A child inherits the disease if both parents carry one sickle cell gene (S) and pass both copies to the child.

Pathophysiology

• Normal vs. Sickle Hemoglobin: Normal red blood cells are flexible and disc-shaped, while sickle cells are rigid and crescent-shaped.
• Effect on Blood Flow: Sickle cells can clump together and block blood flow in small blood vessels, leading to pain and potential organ damage.

Symptoms

• Chronic Symptoms: Anemia, fatigue, jaundice, delayed growth, and puberty.
• Acute Symptoms (Crises): Severe pain (often in bones, joints, chest, abdomen), acute chest syndrome, infections, and splenic sequestration.

Complications

• Infections: Increased risk due to spleen damage.
• Stroke: Due to blocked blood flow to the brain.
• Acute Chest Syndrome: Life-threatening lung complication.
• Organ Damage: Particularly affecting the spleen, liver, kidneys, and lungs.
• Vision Problems: Due to damage to the retina.

Treatment

• Pain Management: Use of pain relievers and hydration.
• Blood Transfusions: To treat severe anemia and prevent complications like stroke.
• Hydroxyurea: Increases fetal hemoglobin production, reducing sickling of cells.
• Bone Marrow Transplant: Potential cure but involves significant risks.
• Gene Therapy: Emerging treatment aimed at correcting the defective gene.

Sources:

Hindu

PRACTICE QUESTION Q.  India is on the cusp of a major breakthrough in the fight against sickle cell anemia through the development of CRISPR-Cas9 gene therapy. Discuss. (10 marks)