Q.The first clinical gene therapy was done for the treatment of:

Gene therapy involves correcting a defective gene that causes a disease. The first clinical application of gene therapy targeted a specific immune disorder.

This disorder is caused by the deficiency of the enzyme adenosine deaminase (ADA), which is essential for the proper functioning of the immune system. Without ADA, the body cannot mount an effective immune response, leading to severe combined immunodeficiency.

The first clinical gene therapy was performed in 1990 on a four-year-old girl suffering from this condition. …

The advent of biotechnology has revolutionized our approach to treating diseases, moving beyond symptomatic relief to addressing the root genetic causes. One of the earliest and most impactful demonstrations of this power came from the use of transgenic organisms. For instance, transgenic bacteria have been engineered to produce human proteins like insulin, which is vital for diabetics. Before this, insulin was extracted from the pancreas of slaughtered cattle and pigs, which often caused allergic reactions in patients. By inserting the human insulin gene into E. coli bacteria, scientists enabled these microbes to produce human insulin efficiently and safely, marking a significant milestone in medical biotechnology. This principle of introducing foreign genetic material for a beneficial outcome laid the groundwork for more complex interventions, such as gene therapy.

Gene therapy represents a frontier in medicine, aiming to correct genetic defects that underlie many diseases. It involves the insertion of genes into a person's cells and tissues to treat a disease, particularly those caused by a single gene defect. The fundamental idea is to replace a faulty gene with a functional one, or to introduce a new gene that can produce a therapeutic protein. This approach holds immense promise for conditions that have no effective cure through conventional methods.

The first successful clinical application of gene therapy occurred in 1990. This landmark treatment was administered to a four-year-old girl who was suffering from Severe Combined Immunodeficiency (SCID).

The specific form of SCID in this case was due to a deficiency of the enzyme adenosine deaminase (ADA). ADA is crucial for the proper functioning of the immune system. Its absence leads to the accumulation of toxic metabolites that destroy lymphocytes, which are essential white blood cells responsible for fighting infections. Without functional ADA, the body's immune system is severely weakened, leaving the individual vulnerable to even common pathogens.

Prior to gene therapy, treatment options for ADA deficiency included bone marrow transplantation, which could be curative if a suitable donor was found, and enzyme replacement therapy (ERT), where functional ADA was injected into the patient. However, both these methods had limitations; ERT was not completely curative and required regular infusions, while bone marrow transplantation depended on donor compatibility.

The gene therapy approach for ADA deficiency involved a sophisticated procedure: …

Method — pin the fact to its year and its disorder, not just its category

1990 is the marker year for "first clinical gene therapy" in this syllabus.

That treatment targeted a specific enzyme deficiency (ADA), causing a specific immunodeficiency (SCID) — not a general category like "cancer" or "AIDS", wh …