CRISPR: Revolutionizing Genetic Engineering and Disease Prevention

Every cell in our body contains a copy of our genome. A human body contains over 20,000 genes and 3 billion letters of DNA. DNA consists of 2 strands, twisted into a double helix and held together by a simple pairing rule: A pairs with T and G pairs with C. It is our genes that shape who we are, as individuals and as a species. Genes also have profound effects on health and due to advancements in DNA sequencing, researchers have identified thousands of genes that affect our risk of disease. To understand how genes work, researchers need ways to control them. Recently a new method has been developed that allows us to edit the genes of any species including humans. The CRISPR method is based on a natural system used by bacteria to protect themselves

When this happens the cell tries to repair the cut but the repair process is error prone leading to mutations that can disable the gene allowing the researchers to understand its function. These mutations are random but sometimes the researchers need to be more precise for example by replacing a mutant gene with a healthy copy. This can be done by adding another piece of DNA that carries the desired sequence. Once the CRISPR system has made the cut, this DNA template can pair up with the cut ends recombining and replacing the original sequence with the new version. All this can be done in cultured cells including stem cells that can give rise to many different cell types. It can also be done in a fertilized egg allowing the creation of transgenic animals with targeted mutations. A major advantage of CRISPR is that, it can be used to target many genes at once. It is a big advantage for studying complex human diseases that are caused not by a single mutation but by many genes acting together. These methods are being improved rapidly and will have many applications in basic research in drug development, in agriculture and perhaps for eventually treating human patients with genetic