Gene therapy concept render

Gene therapy is a technique that modifies genes to treat or prevent diseases, offering hope for previously incurable genetic conditions.

About this subject

Gene therapy involves introducing, removing, or altering genetic material within a patient's cells to correct a disease. The most common approach uses modified viral vectors (e.g., adenoviruses or lentiviruses) to deliver the therapeutic gene to target cells. Alternatively, techniques like CRISPR-Cas9 enable direct DNA editing at the mutation site, cutting and replacing defective sequences.

Clinical applications range from inherited monogenic diseases such as cystic fibrosis and Duchenne muscular dystrophy to cancer treatments. In oncology, CAR-T cell therapy modifies a patient's lymphocytes to recognize and attack tumors. First approved in the West in 2012 (Glybera for lipoprotein lipase deficiency), the field has advanced rapidly, with over 2,000 clinical trials underway globally.

Despite progress, challenges remain: immune response to vectors, off-target effects, durability of gene expression, and high costs (treatments can reach US$2 million). Ethics are also debated, especially germline editing affecting descendants. Strict regulations by ANVISA and the FDA aim to balance innovation and safety.

In Brazil, gene therapy research is conducted by institutions like Instituto Butantan and USP, focusing on neglected diseases and cancer. The future points to more specific therapies, combined with artificial intelligence to predict better targets and reduce costs.

Frequently Asked Questions

Is gene therapy safe?

Safety depends on the method and disease. Rigorous clinical trials assess risks such as immune reactions and unwanted mutations. Approved therapies like Zolgensma for spinal muscular atrophy have an acceptable safety profile, but adverse effects are still monitored.

What diseases can be treated with gene therapy?

Currently, it mainly treats monogenic diseases (cystic fibrosis, hemophilia, muscular dystrophy) and some cancers (acute lymphoblastic leukemia). Research is expanding to complex diseases like Alzheimer's and diabetes.

How does CRISPR gene editing work?

CRISPR-Cas9 uses a protein (Cas9) guided by RNA to cut DNA at a specific location. Cellular repair can then insert or delete genes. It is more precise than viral vectors, but off-target cuts remain a risk.