Abstract
Genetic mutations lead to multiple diseases that affect millions of people worldwide. Since the discovery of the double-helix DNA structure in 1953 by Franklin, Crick and Watson, a lot of research has been conducted to study the technologies that could edit the genetic code. Molecular tools such as ZFNs, TALENs and CRISPR-Cas9 have been developed to modify DNA. ZFNs are programmable and synthetic nucleases made of zinc finger DNA-binding domains fused to a FokI nuclease, and they are capable of making double-stranded breaks in targeted genes. TALENs are proteins that were engineered. They combine TALE DNA-binding domains with a FokI nuclease. They can recognise a specific DNA sequence and then cleave through the double helix. CRISPR-Cas9 technology is based on a bacterial defence mechanism. It utilises a guide RNA to direct the Cas9 nuclease to a specific DNA sequence, where it cleaves the sequence, which is later repaired via cellular mechanisms. All methods have pros and cons, and all of them also need further research to establish how safe they are to eliminate their limitations and eventually use them for personalised medicine. Gene editing tools can be used in various medical fields, such as infectious diseases, hereditary diseases or oncology. However, the application of molecular tools in clinical medicine raises a lot of ethical concerns, such as safety, privacy, consent and the impact of gene editing on society, and potentially risks increased social inequality. There is also a lack of legal guidelines that would specify how gene editing can be used in a clinical setting.