The first-ever CRISPR study in the U.S. has received the green light. Researchers from Editas Medicine and Allergan will conduct the trials. The study will attempt to use CRISPR to edit a specific gene in children and adults that causes blindness, as the Associated Press reports.
The trials will target the inherited disorder Leber congenital amaurosis (LCA) in 18 patients to test “safety, tolerability, and efficacy.” Those affected by LCA have otherwise healthy eyes. However, they lack mutations in the CEP290 gene, which transforms light into brain signals that enable sight. Consequently, they frequently see only bright light and blurry outlines, and the disorder can lead to complete blindness.
Overall, it is the leading cause of inherited childhood blindness, affecting about two out of three births in 100,000.
LCA can often go undetected for generations until an unlucky combination of genes brings out the disorder. The trials will specifically target a variant of LCA called LCA 10 for CRISPR editing. The researchers will deliver a healthy version of the CEP290 gene via a one-time, subretinal injection.
There’s one main difference between this study and other, more controversial CRISPR endeavors. In the LCA study, the gene-editing is in vivo. In other words, the editing happens inside the body rather than in the embryo. Therefore, genetic replacements don’t continue in the genetic line.
A Controversial Past
Chinese biochemist He Jiankui recently drew a lot of criticism from the scientific and ethics communities. He attempted to create HIV resistant embryos and reportedly brought some of them to term. Notably, the move didn’t receive approval from the Chinese government.
Moreover, Russian biologist Denis Rebrikov located five couples who consented to CRISPR gene editing in their future offspring to prevent a form of deafness that both parents carry. Rebrikov’s work has received less criticism, as he claims that he went through the proper channels.
All CRISPR editing comes with a degree of controversy due to its unpredictable nature. However, the LCA study has drawn less due to its relatively unobtrusive, one-time delivery, and the fact that it doesn’t involve embryos.
Furthermore, the edited genes don’t stay in the hereditary line. So, the genetic alterations won’t cause unforeseen, multi-generational consequences. But other companies have turned to non-CRISPR therapy in treating different disorders.
A Beautiful Sight
Sangamo Therapeutics has used another form of in vivo gene editing called zinc fingers to treat metabolic diseases. A treatment called Luxturna has also treated LCA, in much the same way as the Editas and Allergan study. Luxturna involves a retina injection with a modified virus carrying the gene alteration during a brief surgery.
Despite the controversy, CRISPR still excites scientists in its relatively simple way of treating a wide range of afflictions, even AIDS. A recent study out of Temple University cured HIV in a subset of mice.
As the first-ever human CRISPR study, the LCA trial is a milestone. But most importantly, it looks promising in restoring vision to adults of all ages and children starting at age 3. There isn’t a more beautiful sight than the moment someone receives the gift of vision.