Is this a dangerous path? A huge breakthrough could change the lives of people with certain blood disorders. But some worry about the medical and moral side effects.
UK gene therapy at £1.6m per patient
Historic: NHS patients will be among the first in the world to be treated with gene-editing therapy. This new technique involves using tiny scissors (above) to remove sections of DNA. Glossary
Disease - An illness or sickness.
Weak - Not strong.
Inject - To use a needle and small tube to put a liquid such as a drug into a person's body.
Cure - To cause to become completely free of a disease or other unhealthy condition.
Gene - A gene is the basic unit of heredity.
CRISPR - CRISPR-Cas9 allows scientists to remove, add or alter sections of DNA with ease and simplicity.
Expensive - Costs a lot of money.
Evil - Very bad or morally wrong.