The technique relies on natural agents called "zinc finger proteins," which attach to specific genetic sites and control neighboring genes. By creating artificial zinc fingers and attaching them to DNA-cutting enzymes, researchers from Sangamo BioSciences and the Zinc Finger Consortium were able to replace the defective genetic sequence responsible for hemophilia with a healthy version of the gene.
If proven usable in humans, this technique would surpass past genetic treatments for hemophilia, which have at their worst been ineffective and even dangerous:
In previous forms of gene therapy, corrective genes have been inserted into the genome at random sites, for lack of the ability to control where they go. This approach means they are not under their natural control systems and, worse, may be inserted in the middle of some other gene that they disrupt.
“There’s a huge interest in this,” said Dr. Mark A. Kay, a gene therapist at the Stanford University School of Medicine. The genome editing approach “could be game-changing in some applications,” he said.
The zinc finger gene-editing technique could address a number of genetic diseases besides hemophilia. According to the article, researchers are even testing a zinc-finger treatment for AIDS.