All About Crispr, the DNA Tool Behind the New Sickle Cell Therapy

Humans have been manipulating genetics since early civilizations realized that certain traits of crops, animals and people themselves were hereditary. The modern-day mapping of all human genes raised the prospect of learning precisely which genes control which traits and then directly altering their DNA codes. After years of hit-and-miss efforts, a gene-editing system called Crispr that’s cheap, effective and easy to use promises to change our relationship with genetics — for better, worse or both. Its champions foresee using Crispr to control pests, increase food production and treat human diseases. They simultaneously worry that its use could unleash dangerous mutants, designer babies and new weapons of mass destruction. In the meantime, Crispr has given birth to a new biotechnology industry that’s beginning to fulfill its promise in treating intractable illnesses. Late this year, a treatment for sickle cell disease became the first Crispr-based therapy to gain regulatory approval.

Because of Crispr’s ability to cut and paste individual genes, companies have been working to use the technology to rectify DNA flaws that lead to inherited disease. Those efforts came to fruition when two drugmakers, Vertex Pharmaceuticals Inc. and Crispr Therapeutics AG, gained approval to sell Casgevy, a Crispr-based treatment with the potential to cure sickle cell disease. UK authorities gave the green light in November, and US regulators followed in December.