About three years ago I was urging all my listeners and readers to buy CRISPR Therapeutics. Those who followed my advice have done very well. It’s only been a few years since scientists first learned how to precisely and reliably splice the human genome using a tool called CRISPR, making it possible to think about snipping out disease-causing mutations and actually cure, once and for all, genetic diseases ranging from sickle cell anemia to certain types of cancer and even blindness.
In China last November, scientist Jiankui He stunned the genetic community when he announced he used CRISPR to permanently alter the genomes of twin girls to be immune to HIV infection. He edited the twins’ cells when they were embryos meaning their edited genomes can be passed on to their children.
Editas Medicine and Allergan are enrolling patients born with a congenital vision disease into a U.S. test using CRISPR to fix a mutation in the cells of a living human body. Other ongoing trials are treating blood diseases by treating patients’ cells outside of their body and introducing them back to the body, where they would outnumber the diseased cells.
In the Editas study, CRISPR will be introduced directly into the eye where it will repair the genetic mutations in the patients’ vision cells and potentially cure them of their disease. The mutation prevents the photoreceptors from sensing light, which contributes to low vision or blindness. Scientists can design CRISPR to act as molecular scissors to snip a cell’s DNA in specific, pre-determined locations — in this case around the aberrant CEP290 gene — and remove it. Without the mutation, the normal protein can be made and the photoreceptor cells can function as they should.
Scientists agree that CRISPR holds great promise in giving researchers unprecedented power to snip out abnormal stretches of DNA, But as with any technology, there are glitches. Some studies have shown that the gene editing goes awry once in a while, splicing incorrect places in the genome. Then there is the bigger question of what longer term, unanticipated effects man-made edits to the human genome might have.
If CRISPR gene editing works as anticipated, it would essentially eliminate the genetic mutation that these people had been born with, and it could not only restore, but possibly preserve their vision. The treatment will be provided during outpatient surgery, in which the surgeon will inject the molecular gene editing machinery under the retina. The CRISPR mechanics will be encased in a deactivated adenovirus built specifically to deliver its splicing payload to photoreceptor cells. Even if they unload the CRISPR in other cells it’s not biologically dangerous since the gene is only mis-coded in the photoreceptor cells.
The trial is just one of a few underway to test the powerful CRISPR technology around the world. One of the most promising is studying whether gene editing can treat, and effectively cure, blood disorders such as beta thalassemia and sickle cell anemia. The biotech company CRISPR Therapeutics, has engineered a solution to treat both conditions that relies on genetic modifications connected to the production of fetal hemoglobin. In CRISPR Therapeutics’ trials for each disease, doctors remove patients’ bone marrow cells, which contain the stem cells that make all blood cells, treat these stem cells outside of the body with CRISPR to turn on the fetal hemoglobin genes, then give patients strong chemotherapy to remove their existing, diseased bone marrow stem cells and replace them with the CRISPR-edited cells.
For people with beta thalassemia, the gene editing therapy could mean the end to a lifetime of transfusions, and for sickle cell patients, a first-ever treatment. It is believed this is a transformative, one-time cure for life for these diseases.
The first patient with beta thalassemia who was treated with CRISPR has not needed transfusions in four months. The preliminary results are an encouraging.
The trouble with the Gene pool is that there is no lifeguard