National Post (National Edition)
Genetic advancements offer hope for Canadians with inherited vision loss
WE WERE NOT PREPARED FOR AN IRD DIAGNOSIS. WE HAD NO KNOWN FAMILY HISTORY OF THIS TYPE OF CONDITION, SO IT CAME AS A COMPLETE SURPRISE TO US
We often think of genetics in terms of the characteristics we inherit from our birth parents – brown hair, freckles, artistic talent, and so on. But there’s a whole other set of genetic inheritance that can be much more serious.
Inherited retinal dystrophies (IRDs) are diseases caused by mutations in over 270 different genes that can be passed down through generations. Individuals with an IRD experience progressive loss of vision and may become blind. The vision loss that occurs in IRDs is a result of genetic mutations that interfere with the way the eye would normally function.
One of the genes that can be mutated in IRDs is the RPE65 gene. RPE65 gives the body information on how to make an essential protein for normal vision. If a child inherits a mutated RPE65 gene from its parents, they can develop an IRD that can lead to complete blindness.
Dr. Robert Koenekoop is a Montreal-based clinician-scientist at the Montreal Children’s Hospital specializing in IRDs. He has spent the past 25 years studying the genes responsible for IRDs. “Back in 1995, when I began working in this area, we were just starting to identify the genetic cause of IRDs,” says Dr. Koenekoop. “It was devastating. We had nothing to say to patients. I felt hopeless and helpless.”
According to Dr. Koenekoop, one of the first signs of an early onset IRD can be when a parent or caregiver notices that the baby isn’t looking at them directly, their eyes are darting back and forth, or they press on their eyes with their fists or fingers.
When Sarah Banon’s first child, Sam, was just two months old, Sarah noticed he was not tracking objects or making eye contact, and that he exhibited rapid eye movement. Unaware that there could be a genetic cause, Sarah first consulted with a pediatrician and an optometrist before finally being referred to Dr. Koenekoop. “He was debating between two diagnoses – both involving genetic mutations – and then we got the blood test results, which showed Sam has an RPE65 mutation.”
Sarah began taking Sam to physio- and occupational therapy appointments. She also had to ensure special adjustments were made at Sam’s school, such as enlarged reading materials and colour-contrasted worksheets. “We had to live in the trenches with the teachers at the beginning of the year to explain these types of things,” shares Sarah.
Fighting Blindness Canada (FBC) has funded vision research in Canada for 46 years. Doug Earle is FBC’s President and CEO: “When we first started, people would see their vision specialist only to be told that they should learn Braille and get ready to go blind. Now, when they call our Health Information Line, we have so many more resources to offer, including information about genetic testing for IRDs by province.”
According to a newly published Canadian report, IRDs cost our society $1.6 billion in 2020 – most of which can be attributed to anxiety, depression, and social isolation of the patients and their families. “This is the first time we’ve seen a financial number to represent the impact of IRD vision loss on overall health and wellness,” explains Doug. “Two thirds of the cost of an IRD are borne by individuals and their families’ wellbeing. This is a significant burden that must be addressed.”
Sarah urges parents to trust their instincts if they feel something is wrong in their child’s development.
In cases like Sam’s, where genetics play a key role, parents are grateful for advances in genetic testing which help secure a diagnosis that is not possible through eye tests alone. “They can’t communicate at such a young age. We would not be where we are now if we hadn’t pushed. Children are adaptive but you need to get a diagnosis to know what you’re up against.”
Dr. Koenekoop is excited by advancements in the genetics of IRDs and other blinding disorders, allowing him to be among the first to offer hope to patients. “Science is moving at such a fast pace. We are never going to look back.” Sarah knows first-hand what it’s like to be able to see a different future for her child due to advancements in IRD research. “The idea that we could give Sam the ability to lead some type of independent life is extremely motivating for us.”
Are you concerned about your child’s vision? Speak to a doctor or vision specialist as soon as possible. If you’ve received an IRD diagnosis, visit fightingblindness.ca for information and resources about genetic testing, to access FBC’s Health Information Line or join the FBC Patient Registry.