As scientists explore ways to use genetic engineering to battle blindness, it’s obvious that gene therapy has gotten more sophisticated.
In traditional gene therapy, scientists “fix” a broken gene by supplying a healthy version to affected cells. Researchers have used this type of gene therapy to treat many diseases, including, as Tina Hesman Saey reports, a rare form of inherited blindness. But that’s an option for only a select few. Saey describes a new technique that could potentially benefit many more people. It doesn’t “fix” a broken gene but rather re-engineers the eye. Transforming nearby nerve cells into cells able to detect light can bypass damaged rods and cones and still get a message to the visual part of the brain.
This approach has already been done with low-resolution electronic implants. But the new technique could boost that resolution 100,000-fold. Human trials have yet to start, but researchers have gotten very good at enabling mice to see.
As Saey was finishing this story, a new report suggested that gains from the current gene therapy method might be short-lived: In some people who regained significant vision after the procedure, the gains later diminished. Disappointing, sure, but the scientists who reported the finding seemed to take it in stride. That’s because, in science, not everything works perfectly the first time. You do experiments, you improve things, you figure things out. It’s the scientific process.
Which leads me to another story by Saey. Chinese researchers have reported editing a gene in a human embryo, stirring a boiling ethical debate about engineering genes in the human germ line, Gattaca-style. While the success rate was low, and the embryos would not have been able to grow into fetuses (having been created with three sets of chromosomes), the report still bolstered calls for a ban on tinkering with genes in human eggs, sperm or embryos. That seems premature. These techniques have the potential to help many; seeing if they can ever become “safe and effective” should be scientists’ goal. And that requires more research. If the techniques do pan out, we should trust that it’s possible to make rules for using that technology appropriately.