CRISPR and VISION

Do you wear glasses or contacts? Ever find them . . . inconvenient?

I wear both and I must admit, I don’t really like either. But I’m incredibly grateful for the gift of sight. When I’m fumbling around for my glasses, I sometimes wonder what it would be like to not see anything at all. 

According to the World Health Organization, at least 2.2 billion people have vision impairment or blindness. In the United States, approximately 1% of children and 2% of adults are considered blind, meaning that they must find other ways to do things people with normal vision do with their eyes.

LCA10

Leber’s congenital amaurosis (LCA) is the leading cause of blindness in childhood. The symptoms of LCA vary, but most people born with the condition are legally blind. They may only be able to differentiate between dark and light and see limited movement.

There are several types of LCA. Type 10 is caused by a single mutation—or spelling mistake—in a gene called CEP290.The mutation is inherited from both parents, who are generally unaffected. Scientists aren’t totally sure what the protein made by CEP290 is supposed to do. But they do know that when it’s not working properly, light-sensing cells in the retina stop working too.   

Never heard of LCA? That’s probably because it only affects 2 to 3 people out of 100,000. But the condition hit the news headlines earlier this year when a person with LCA10 became the first to receive CRISPR treatment administered directly into the body. 

CRISPR

The treatment is part of a clinical trial—which goes by the rather confident-sounding name BRILLIANCE—being run as a partnership between Oregon Health & Science University (Portland), Editas Medicine (Cambridge, Massachusetts), and Allergan (Dublin). It uses a system called CRISPR to fix a mutation in CEP290 through gene editing. 

Gene therapy is not new. In fact, I did a thesis project on it during the last year of my undergraduate degree (which was longer ago than I care to admit). This trial differs from the ones that came before in two very significant ways: 

  • CEP290 is edited to fix the spelling mistake, not replaced with an entirely new gene.
  • CRISPR is injected directly into the eye, not into cells that have been removed from the eye.

It won’t take long for BRILLIANCE scientists to know whether CRISPR can restore vision in people with LCA10. If successful, CRISPR could be used to treat other forms of inherited blindness. It may even bring us closer to a cure for more common forms of vision impairment. 

This raises the question of how society defines disease as discussed in a recent Discover Magazine article, Why Deaf People Oppose Using Gene Editing to “Cure” Deafness. It also forces us to consider the line between disability and enhancement. What if, for example, CRISPR techniques become so advanced that we could give someone X-ray vision?

It may sound like science fiction, but it’s a possibility we should all be aware of as gene editing moves forward. To find out more, pre-order CRISPR: A Powerful Way to Change DNA, available through Annick Press, online retailers, and your local bookstore.   


Image credits: Clker-Free-Vector-Images (pixabay), PNGKit, Piotr Siedlecki (publicdomainpibtures.net)