What do we mean by ‘genome editing’?

Almost all cells of any living organism (e.g. a human, animal, plant, bacterium) contain DNA, a type of molecule that is passed from one generation to the next during reproduction. DNA is involved in many essential biological processes including building cells and controlling their number and type, the production of energy, the regulation of metabolism, and fighting disease.

The term ‘genome’ generally refers to the entire sequence of DNA of an organism. The genome includes genes: sequences of DNA with specific functions that are involved in the production of the proteins needed to carry out many biological roles. It also includes regions of DNA that promote or inhibit gene activity, and regions that do not appear to affect protein production or function.

Genome editing is the deliberate alteration of a selected DNA sequence in a living cell. A strand of DNA is cut at a specific point and naturally existing cellular repair mechanisms, then fix the broken DNA strands. The way they are repaired can affect gene function and new DNA sequences can be delivered when the DNA is cut and act as templates for generating an altered sequence. Genome editing techniques can be used to delete sections of DNA or alter how a gene functions: for example, by changing a variant that may give rise to disease to one that functions normally