Source: HINDU
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Indian scientists have achieved a significant milestone in medical research by developing a novel gene therapy for haemophilia A. This breakthrough could transform the lives of thousands of patients in India and potentially worldwide.
Haemophilia A is caused by the lack of Factor VIII which is a critical blood-clotting protein.
Severe cases involve less than 1% of normal Factor VIII levels leading to frequent and potentially fatal bleeding episodes.
Traditional treatments involve repeated infusions of Factor VIII or alternative clotting agents. This gene therapy introduces a therapeutic gene that enables the body to produce Factor VIII autonomously.
Unlike existing therapies like Roctavian which use adenoviruses for gene delivery, this new method avoids adenovirus vectors. The safer mechanism opens the possibility of applying the therapy to children.
Suitable for patients with less than 1% clotting factor a group typically reliant on repeated treatments.
India has the second-largest haemophilia patient pool globally estimated at 40,000 to 1,00,000 individuals.
Severe Haemophilia A is particularly common and challenging to manage.
Conventional treatment costs around ₹2.54 crore per patient over 10 years. Gene therapy offers the potential to reduce long-term costs by eliminating the need for repeated infusions.
Aspect |
Roctavian |
Indian Therapy |
|
Approval |
U.S. FDA-approved in 2023. |
Trial stage, reported success in India. |
|
Gene Delivery |
Uses adenovirus vectors. |
Safer alternative to adenovirus. |
|
Effectiveness |
Reduced bleeding incidents from 5.4 to 2.6/year. |
Zero bleeding episodes over 14 months in trials. |
|
Target Demographic |
Adults only. |
Potentially suitable for children. |
Hemophilia is a rare genetic disorder characterized by the inability of the blood to clot properly due to the deficiency of specific clotting factors. This condition primarily affects males and is inherited in an X-linked recessive pattern.
Characteristic |
Description |
|
Types |
Hemophilia A: Deficiency of Factor VIII Hemophilia B: Deficiency of Factor IX |
|
Inheritance |
X-linked recessive; predominantly affects males, while females are carriers. |
|
Incidence |
Approximately 1 in 5,000 male births for Hemophilia A and 1 in 30,000 for Hemophilia B. |
|
Symptoms |
Prolonged bleeding, spontaneous bleeding, bruising, joint pain/swelling and nosebleeds. |
In hemophilia, the clotting process is disrupted due to the absence or deficiency of clotting factors leading to:
Blood takes longer to coagulate at the site of an injury.
Recurrent bleeding can cause hemophilic arthropathy (joint damage).
Severe cases may experience life-threatening hemorrhages.
Mutations in the F8 gene (Hemophilia A) or F9 gene (Hemophilia B) lead to clotting factor deficiency.
About 30% of cases arise due to de novo mutations without a family history.
|
Mild Hemophilia |
Bleeding occurs only after surgeries or injuries. |
|
Moderate Hemophilia |
Occasional spontaneous bleeding and prolonged bleeding after minor trauma. |
|
Severe Hemophilia |
Frequent spontaneous bleeding, especially into joints and muscles. |
Approach |
Details |
|
Replacement Therapy |
Regular infusions of missing clotting factors (VIII for Hemophilia A, IX for Hemophilia B). |
|
Desmopressin (DDAVP) |
Stimulates release of stored Factor VIII for mild Hemophilia A. |
|
Antifibrinolytics |
Medications like tranexamic acid to prevent clot breakdown. |
|
Gene Therapy |
Emerging treatments aim to deliver functioning copies of defective genes. |
|
Lifestyle Modifications |
Avoid high-risk activities, maintain healthy weight and use protective gear. |
Gene TherapyGene Therapy is a medical intervention that modifies, replaces or silences defective genes in a patient’s genome to cure or mitigate disease.
Replace defective or mutated genes.
Inactivate or knock out malfunctioning genes.
Introduce new or modified genes to improve function or fight disease.
Type |
Description |
|
Somatic Gene Therapy |
Targets non-reproductive cells; changes do not pass to offspring. |
|
Germline Gene Therapy |
Targets reproductive cells (sperm/egg); genetic modifications are heritable. |
|
Ex Vivo Therapy |
Genetic material is altered outside the body and reintroduced into the patient. |
|
In Vivo Therapy |
Genetic material is directly delivered into the patient's body. |
Approach |
Description |
|
Gene Replacement |
Defective or missing genes are replaced with functional copies. |
|
Gene Silencing |
Uses techniques like RNA interference (RNAi) to suppress faulty gene expression. |
|
Gene Editing |
Techniques like CRISPR-Cas9 allow precise modifications in the DNA sequence. |
|
Gene Augmentation |
Adds a gene to produce beneficial proteins in cases of deficiency. |
Vectors are vehicles that deliver therapeutic genes into the target cells.
Vector Type |
Features and Usage |
|
Viral Vectors |
Modified viruses (e.g., adenovirus, lentivirus) used for efficient gene delivery. |
|
Non-Viral Vectors |
Liposomes or nanoparticles used for safer but less efficient, gene delivery. |
|
CRISPR-Cas9 |
A precise gene-editing tool that can insert, delete or modify specific genes. |
Field |
Examples |
|
Genetic Disorders |
Treats disorders like cystic fibrosis, sickle cell anemia, and hemophilia by addressing root causes. |
|
Cancer Therapy |
Modifies immune cells to target cancer cells (e.g., CAR-T cell therapy). |
|
Infectious Diseases |
Alters genes to make cells resistant to viruses like HIV. |
|
Rare Diseases |
Offers hope for diseases like spinal muscular atrophy (SMA) and Leber’s congenital amaurosis. |
Treats the underlying genetic defect rather than managing symptoms.
Offers long-term or permanent solutions for many genetic and chronic diseases.
Enhances quality of life for patients with debilitating conditions.
Tailors treatments to an individual's genetic makeup.
Challenge |
Description |
|
Delivery Efficiency |
Difficulty in delivering genes precisely to target cells or tissues. |
|
Immune Response |
Potential immune reactions to viral vectors or introduced genes. |
|
High Costs |
Gene therapy is expensive making accessibility a challenge. |
|
Ethical Concerns |
Germline gene therapy raises debates about human genetic modification and future impacts. |
|
Durability of Effects |
Uncertainty about how long therapeutic effects will last in some cases. |
Innovation |
Details |
|
CRISPR-Cas9 |
Allows precise gene editing, making therapies more effective and safer. |
|
AAV Vectors |
Adeno-associated viruses have emerged as safer viral vectors with reduced immune response risks. |
|
CAR-T Cell Therapy |
Genetically modifies T-cells to target and destroy cancer cells. |
|
RNA-Based Therapies |
Uses RNA interference (RNAi) to silence harmful genes. |
Sources:
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PRACTICE QUESTION Q.Consider the following statements about gene therapy:
Options: Answer: B) Explanation: Statement 1 is correct. Gene therapy modifies genetic material within cells to address diseases. Statement 2 is incorrect. While gene therapy shows promise for conditions like haemophilia and cystic fibrosis, its success is limited to trials and specific regions not yet on a global scale. Statement 3 is correct. Adenoviruses are widely used vectors for delivering therapeutic genes, though safety concerns exist. |
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