When Carlene Knight was a little girl growing up in the rural Eastern Oregon town of Adrian, she loved to ride her bike on the gravel road near her family’s farmstead.
Instead of pedaling alone, Knight always followed the outline of one of her four siblings, who would ride in front of her as they went down the road together in a straight line. They did this because Knight couldn’t see clearly enough to ride a bike on her own. Bicycling behind others is one of many adaptations Knight has made over her lifetime to live in a seeing world.
Now 54 and living with her husband in the Portland suburb of Happy Valley, Knight was born with limited vision due to mutations in her CEP290 gene. Such mutations cause a rare condition known as Leber congenital amaurosis type 10, which leads most people who have them to either be born blind or become blind within the first decade of their life. Soon, Knight hopes advances in medical science can improve vision for people with this condition.
‘Use my genes to help others’
Knight is a participant in the Phase 1/2 BRILLIANCE clinical trial, which is evaluating a potential gene editing called EDIT-101. Developed by Editas Medicine, the CRISPR-based investigational treatment is designed to repair mutated CEP290 genes. Knight volunteered for the clinical trial through the Oregon Health & Science University Casey Eye Institute, where she underwent the investigational procedure within the past year.
Although it’s too soon to know if the experimental treatment will impact her own vision, Knight volunteered for the trial to help children enhance their own lives with the increased opportunities that sight can bring, adding: “This is an opportunity to use my genes to help others.”
Knight said it’s also fun to be part of cutting-edge research.
“It’s not every day that you can say you had your genes altered,” Knight continued. “Genes have seemed like a concrete idea for a long time, like you’re stuck with what you’ve got. But this whole gene therapy thing is fascinating. It feels like uncharted territory.”
She was born with no peripheral vision, which means she’s only able to see directly in front of her, as if she is always looking through a straw. When Knight was a child, she could read the large letters on cans of food with the help of a magnifying glass. A special teacher also came to her school twice a week to help Knight learn skills, like how to cook, fold laundry and read Braille.
Her eyesight substantially declined by the time she was in her 20s, and it became impossible to read even the largest of letters. But she has been able to identify colors and the contrast of dark and light objects, which helps her distinguish walls from doorways.
Doing things differently
“I want you to know that we can do just about anything they can,” Knight said of people living with impaired vision. “We may just need to do it differently, or it may take a little bit longer.”
Instead of driving herself, Knight uses public transit or walks. She wields a white cane to identify potential obstacles while setting out on foot. She also listens to descriptive captioning, or the voiceover narration available with television shows, instead of watching a TV screen. And Knight uses a machine called a Braille display, which translates text displayed on a computer screen into three-dimensional raised dots representing words that she reads with her fingertips. As a call center worker, she uses the machine to help guide phone conversations with donors for charities.
Considering the possibilities
Although Knight is content with her life, participating in the trial has led her to wonder what might be different if she had better eye sight.
“If I could just read those can labels again, see a bus stop sign, observe facial expressions or enjoy the scenery,” said Knight, as she considered the possibilities. “And I would love to be able to read my 3-year-old granddaughter a book.”
Knight had substantially limited vision before joining the trial, and it’s unknown whether the experimental EDIT-101 treatment will improve her eyesight. But, even if it doesn’t, she hopes her involvement in the BRILLIANCE clinical trial will help others.
“We are grateful for patients like Carlene, who volunteer to be part of these novel clinical trials. We could not advance science without their participation,” said Mark Pennesi, M.D., Ph.D., who leads OHSU’s involvement in the trial, is the Kenneth C. Swan associate professor of ophthalmology in the OHSU School of Medicine, and chief of the OHSU Casey Eye Institute’s Paul H. Casey Ophthalmic Genetics Division.
Editas Medicine plans to share clinical data from the BRILLIANCE trial by the end of 2021. The trial began in early 2020, when OHSU Casey Eye Institute staff performed the trial’s first procedure. That milestone was the first time CRISPR gene editing had been done inside the human body.