Gene therapy concept render

Gene therapy is a molecular medicine technique that inserts healthy genes into cells to treat genetic diseases, with recent advances like CRISPR.

About this subject

Gene therapy involves introducing functional genetic material into a patient's cells to correct hereditary or acquired defects. The therapeutic gene is typically delivered by a viral vector, such as adenovirus or lentivirus, modified to be non-pathogenic. Once inside the cell, the gene can replace a faulty gene, silence a harmful mutation, or confer a new function, like the ability to fight tumors.

The first clinical gene therapy trials began in the early 1990s, but a tragic milestone was the death of Jesse Gelsinger in 1999 from an immune reaction to the viral vector, leading to stricter protocols. Over subsequent decades, advances in vector engineering and human genomics enabled the development of safe and effective treatments.

Today, gene therapy is approved for several diseases. Luxturna (voretigene neparvovec) treats inherited retinal dystrophy, while Zolgensma (onasemnogene abeparvovec) is used for spinal muscular atrophy. CRISPR-Cas9 gene editing, which allows precise DNA cutting and modification, has opened new frontiers, with trials for sickle cell disease and beta-thalassemia.

Despite progress, gene therapy faces challenges such as high costs, efficient delivery to specific tissues, and ethical issues surrounding germline editing. In Brazil, the public health system (SUS) included Zolgensma in 2022, expanding access, but regulation and funding remain central topics for the technique's expansion.

Frequently Asked Questions

How does gene therapy work?

Gene therapy delivers a functional gene into the patient's cells using a viral or non-viral vector. This gene can compensate for a genetic defect, silence a mutation, or add a new therapeutic function.

What are the risks of gene therapy?

Main risks include immune reactions to the vector, incorrect gene insertion that may cause cancer, and toxicity. Rigorous clinical trials monitor these effects.

What diseases can be treated with gene therapy?

Currently, hereditary conditions like retinal dystrophy, spinal muscular atrophy, and certain sickle cell diseases have approved therapies. Trials also explore treatments for cancer (CAR-T) and neurodegenerative disorders.