If you have a mutation in one gene that makes you sick, wouldn’t it be great to cut it out? There has been progress to do just that. A new technique called CRSPR works like this; A virus is used to shuttle a gene into a cell that codes for the enzyme CAS9. CAS9 is then taken to a specific place on the gene by RNA molecules where it will cut a defective gene out of the DNA. Until recently, the gene that enters the cell and spurs CAS9 production had too many DNA letters to fit inside the virus that carries it to the cell. Now scientists have found a gene in bacteria that codes for CAS9 and is much shorter. This is good news for those with diseases who might one day be cured if one offending gene can be removed and replaced.
It’s also good for ethics. Until recently, it was easier to edit genes in an embryo where there are fewer cells, but the experimental embryo and future generations are unable to consent to any changes that would take place. Not to mention, it’s not known if such editing on a human embryo is harmful. There are unconfirmed reports that human trials have been done, but new study shows that we may soon be able to edit gene sequences in complex, specialized adult cells.
A recent study sent the shorter sequence into mice with the target being a cholesterol regulation gene in the mice’s livers. After just one week 40% of the liver cells contained the modified gene.
It’s good news for anyone with one of the thousands of diseases that could be cured if specific genes in a specific cell type could be modified, but it leads to other questions. What if some people want to add plant or animal genes to their own? What if it did become acceptable to “edit” unborn children’s genomes? Researchers point out that traits like height, eye color, and hair color have so many genes that code for them it would be nearly impossible to find all their interactions and modify them, so we probably won’t have designer babies, or designer adults, for a while, but if we keep improving gene editing, is it impossible?
Or as in my novel, what if you could activate genes that make you nearly immortal?
If optional, non-medically necessary genetic edits did lead to a better quality of life, how would society change?
New Discovery Moves Gene Editing Closer to Use in Humans
Heidi Ledford and Nature magazine