“You don’t know what you’ve got ‘til it’s gone.”
These words were made famous by singer Joni Mitchell and ring true of many circumstances in life. Perhaps nowhere more so than when we talk about our vision. In this case, I am referring to the rare eye disease known as choroideremia (CHM for short). At Penn Medicine we see many patients with rare and difficult-to-treat eye diseases, but CHM is getting a lot of attention around here these days.
Jean Bennett, MD, PhD, professor of Ophthalmology and director of the Center for Advanced Retinal and Ophthalmic Therapeutics (CAROT) at Penn Medicine, is a leader in using gene therapy for the treatment of rare eye diseases. What does this mean? She is essentially replacing a defective, disease-causing gene with a newer, working version of it. As Dr. Bennett said in a recent interview, “We’re basically taking advantage of viruses. What they do best is they deliver genes or nucleic acids to the target cells. But instead of using a virus which is found in the wild we’ve basically taken one which has never been shown to cause any disease and neutered it by removing its guts and replacing its guts with the gene of interest.”
So far, Bennett and her team have used gene therapy to treat a rare condition known as Leber’s Congenital Amaurosis or LCA. Patients with LCA are born severely visually impaired. They can sense light and see very large objects but with poor resolution and poor peripheral vision, all of which deteriorates with age. Bennett’s lab was able to deliver a normal copy of the gene which when mutated causes LCA to obtain amazing results. Many of the patients in the study showed improved vision and light sensitivity: a child who walked with a cane can now ride his bike and read; mothers could see their children clearly for the first time.
Bennett is next looking to tackle the rare eye disease, choroideremia. With a clinical trial planned for this fall, those suffering from the disease are hoping this will yield the same life-changing results. A small, but determined group, they are working with Dr. Bennett and the Chorioderemia Research Foundation to bring attention to the disease through running.
Team CHM
Jeff Benelli has chorideremia. He’s 48 and has a field of vision that he equates to looking at the world through an empty toilet paper tube. He can see better at long distances, but up close he can barely make out facial features and has a visual field (the ability to see objects to the left, right, up and down) of about one degree, whereas the normal person can see 180 degrees in all directions. He stopped driving 13 years ago, but an avid sportsman, Jeff can still run.
This summer, the leadership of the CHM Research Foundation started “Team CHM” and set out to take on races, from large to small, to spread awareness of CHM and simultaneously show what they CAN do.
Jeff’s challenge: to run four marathons in five weeks, ending with the Philadelphia marathon on Sunday, November 23rd, along with several other members of Team CHM. Choiroideremia sufferers, supporters, friends and family will descend on Philadelphia to run or cheer on the team members. He completed the Kansas City marathon last week and has three more to go.
Danny Boren also suffers from CHM and is the engine behind “Team CHM.” He and his wife Sharyl will complete an Ironman triathalon on November 16th, followed by the Philadelphia marathon a week later. Danny, age 36, has a visual field of about 18 percent; he doesn’t drive or surf anymore, but he too can run (and bike and swim). His diagnosis was confirmed by Dr. Bennett several years ago. As CHM is a degenerative disease, his vision and Jeff’s, will only get worse.
Both were born with fairly normal vision and over time their vision will worsen so that eventually they will be left with a tiny little pinpoint of vision. Choroideremia is what’s called an x-linked retinal degeneration, which means that only males manifest the disease and that the females – the moms - are carriers.
“Imagine dropping your pencil on the floor with only a tiny field of vision,” Bennett recently said. “It’s really hard to find the pencil. Imagine being a doctor with this condition and trying to find your patient in a lobby. It’s very difficult.” It can also be psychologically devastating for these people to experience the continuing deterioration of their vision.
The great hope is that Bennett and her team will be able to halt the disease in its tracks to preserve the vision both Jeff and Danny and other CHM sufferers have as early in life as possible.
When asked why they decided on the Philadelphia marathon, both men agreed without hesitation that their choice “has everything to do with the group at Penn. We want to celebrate the work that the team at Penn has done, and show how far we’re willing to go to find a way to end this disease.”
For more information on the CHM Research Foundation or to contribute to Jeff and Danny’s efforts, visit www.curechm.org.
Photo caption #1: Jeff Benelli runs a recent marathon. Jeff is in the process of running 4 marathons in 5 weeks, ending with the Philadelphia marathon on Sunday, November 23rd.
Photo caption #2: Danny and Sharyl Boren. Danny and Sharyl will run an Ironman Triathalon on November 16th, followed by the Philadelphia Marathon on November 23rd. Both men are raising funds to fight the rare eye disease, chorioderemia, from which they both suffer.