CRISPR is causing a major upheaval in biomedical research.  It is cheap, quick and easy to use, and it has swept through labs around the world as a result.

What is CRISPR? - it is an abbreviation for ‘clustered regularly interspaced short palindromic repeats’. It was  initially found in bacteria as a resistance mechanism to foreign genetic material such as plasmids and phages.

CRISPRs are associated with cas genes that code for proteins related to CRISPRs —  Cas9 for instance  By delivering the Cas9 protein and appropriate guide RNAs into a cell, the organism's genome can be cut at any desired location. Researchers only need to order the RNA fragment; the other components can be bought off the shelf. Total cost: is as little as $30. This effectively democratises the technology so that anyone can use it.

Last year, bioengineer Daniel Anderson of the Massachusetts Institute of Technology in Cambridge and his colleagues used CRISPR in mice to correct a mutation associated with a human metabolic disease called tyrosinaemia. It was the first use of CRISPR to fix a disease-causing mutation in an adult animal — and an important step towards using the technology for gene therapy in humans.

What are the risks?

Many researchers are deeply worried that altering an entire population, or eliminating it altogether, could have drastic and unknown consequences for an ecosystem. They are also mindful that a guide RNA could mutate over time such that it targets a different part of the genome. This mutation could then race through the population, with unpredictable effects - the risk of the accidental release of an experimental gene-drive.

What is a gene-drive?

First let us look at how mutations are normally spread within  populations.

With gene-drive the genetic change would spread rapidly throughout the population since at each mating the genetic change would occur in both parents.

For further information, the source article is: Nature 522, 20–24 (04 June 2015)