If the human genome is the book of life, then Crispr technology is its Microsoft Word. The cut-and-paste technique, invented only three years ago, can be used on fledgling genomes to snip out bits of DNA and, if required, insert new stretches.
The amendments are permanent and can be passed down the generations. The technology works on mice and men; a team in China recently revealed they had partially succeeded in excising the gene for beta thalassaemia, an inherited blood disorder, from a human embryo. It is a wonder society is not yet spooked by what could be a defining technology for the future of humanity.
Crispr — short for clustered regularly interspaced short palindromic repeats — is the simplest of a suite of new gene-editing technologies, and is a trick borrowed from the bacterial immune system. Bacteria, when invaded by a virus, deploy “molecular scissors” — a DNA-cutting enzyme that chops up the invader. Pair the scissors with a guiding molecule capable of directing the blades to a specific point, and you are ready to edit a genome. After the DNA is severed, cellular repair machinery kicks in to close the gap and the embryo continues to develop. This is how the Chinese scientists banished the mutant gene from their human embryo.