X-linked retinoschisis (XLRS) is an inherited retinal diseasing causing vision loss due to splitting of the layers of the retina.
About the Disease
X-linked retinoschisis (XLRS) is an inherited disease that causes loss of central and peripheral vision due to degeneration of the retina. The retina is a thin piece of tissue lining the back of the eye. Rod and cone photoreceptors in the retina convert light into electrical signals that the brain interprets as vision. About 35,000 people in the United States and Europe have the condition.
XLRS leads to vision loss due to the splitting of retinal layers, which leads to degeneration of photoreceptors. It is caused by mutations in the RS1 gene. The RS1 protein act likes an adhesive to hold the retinal layers together.
XLRS occurs most frequently in males. Although the condition begins at birth, symptoms do not typically become apparent until after the age of 10. About half of all patients diagnosed with retinoschisis notice first a decline in vision. Other early symptoms of the disease include the inability of both eyes to focus on an object (strabismus) and roving, involuntary eye movements (nystagmus).
Vision loss associated with juvenile retinoschisis is caused by the splitting of the retina into two layers. This retinal splitting most notably affects the macula, the central portion of the retina responsible for perceiving detail and colors. On examination, the fovea (the center of the macula) has spoke-like streaks. The spaces created by the separated layers are often filled with blisters and ruptured blood vessels that can leak blood into the vitreous body (the transparent, colorless mass of jelly-like material filling the center of the eye). The presence of blood in the vitreous body causes further visual impairment. The vitreous body degenerates and may eventually separate from the retina. The entire retina may also separate from underlying tissue layers causing retinal detachments.
The extent and rate of vision loss vary greatly among patients with XLRS. Central vision is almost always affected. Peripheral (side) vision loss occurs in about half of all cases. Some patients retain useful vision well into adulthood, while others experience a rapid decline during childhood.
XLRS is genetically passed through families by the X-linked pattern of inheritance. In this type of inheritance, the gene for the disease is located on the X chromosome. Females have two X chromosomes and can carry the disease gene on one of their X chromosomes. Because they have a healthy copy of the gene on their other X chromosome, carrier females are often not affected by X-linked diseases such as XLRS. However, in recent years, more females have been identified with having vision loss from X-linked conditions.
Males have only one X chromosome (paired with one Y chromosome) and are therefore genetically susceptible to X-linked diseases. Males affected with an X-linked disease always pass the gene on the X chromosome to their daughters, who then become carriers. Affected males never pass an X-linked disease gene to their sons, because fathers pass the Y chromosome to their sons.
Female carriers have a 50 percent chance (or 1 chance in 2) of passing the X-linked disease gene to their daughters, who become carriers, and a 50 percent chance of passing the gene to their sons, who are then affected by the disease.
Genetic counselors are excellent resources for discussing inheritability, family planning, genetic testing, and other related issues.
The National Eye Institute and Applied Genetic Technologies Corporation have launched gene therapy clinical trials for XLRS. Gene therapies work by delivering copies of healthy genes to the retina to replace the defective copies that are causing vision loss.
The Foundation is funding other research projects to identify compounds that can preserve vision. Future stem-cell treatments might also benefit people with retinoschisis.
A recent study showed that a drug called dorzolamide may improve retinal health and restore some vision in people with retinoschisis.
Individuals with XLRS may also benefit from the use of low-vision aids, including electronic, computer-based, and optical aids.
Orientation and mobility training, adaptive training skills, job placement, and income assistance are available through community resources.
Mar 31, 2020 Foundation News
The Foundation Fighting Blindness is closely monitoring the COVID-19 situation and its impact on the IRD community.
Feb 6, 2020 Foundation News
The Foundation Fighting Blindness is pleased to provide an audio recording and full transcripts of the Insights Forum, our quarterly conference call providing updates to the inherited retinal disease community. The call took place on January 31, 2020.
Feb 6, 2020 Press Releases
ProQR Therapeutics Teams Up with the Foundation Fighting Blindness and Blueprint Genetics to Support the My Retina Tracker® Program for People Living with Inherited Retinal Diseases
My Retina Tracker Program is the highest volume IRD genetic testing program in the U.S.
Oct 2, 2019 Press Releases
Blueprint Genetics, InformedDNA and the Foundation Fighting Blindness launch an open access program for patients with inherited retinal disease in the United States
The program will offer patients with inherited retinal disease no-cost genetic testing and genetic counseling in the United States. Look for updated information on how to participate to be posted in mid-October, with program registration starting shortly thereafter.
Aug 16, 2019 Foundation News
The newly funded research efforts include several therapies that have strong potential to treat a wide range of inherited retinal diseases.
May 9, 2019 Press Releases
Bipartisan Bill Will Stimulate Up to $1 Billion in New Funding for Blindness Research
Jul 19, 2018 Press Releases
Bill Introduced in U.S. House Would Speed Up Cures for Blindness
Jun 8, 2018 Press Releases
Foundation Fighting Blindness and CheckedUp® Partner to Educate Retinal-Disease Patients About Research, Resources, and Emerging Therapies During Doctor Visits
The Foundation Fighting Blindness (the Foundation) and CheckedUp have formed a collaborative partnership to deliver patient-friendly diagnostic and disease-management information to people with retinal diseases such as age-related macular degeneration, retinitis pigmentosa, and Stargardt disease during their visits to eye doctors.
Feb 7, 2020 Science Education
The benefits of genetic testing for IRD patients, how to participate in the Foundation’s Open Access program, and what to expect from the genetic testing process.
Jun 17, 2019 Science Education
Retinal research paves the way for new treatments for the entire neurological system.
May 20, 2019 Eye On the Cure Research News
Dr. Zack is a member of the Foundation’s Scientific Advisory Board and chairs its Cellular Molecular Mechanisms of Disease study section.
May 9, 2019 Eye On the Cure Research News
Eye Bonds Re-Introduced to New Congress: Potentially $1 Billion in Government-Backed Funding for Eye Research
Eye Bonds provide the opportunity to advance, and accelerate development for, more promising treatments into and through clinical trials and out to the people who need them.
Jan 29, 2019 Eye On the Cure Research News
Sofia Sees Hope, a nonprofit dedicated to finding treatments and cures for people with Leber congenital amaurosis (LCA) and other inherited retinal diseases (IRDs), has made a $100,000 donation to the Foundation Fighting Blindness to support therapy development and genetic testing.
Jan 17, 2019 Eye On the Cure Research News
The French bioelectronics company Pixium Vision has reported that its PRIMA bionic vision system has restored some central vision in patients with advanced dry age-related macular degeneration (AMD) participating in a clinical feasibility trial.
Dec 21, 2018 Eye On the Cure Research News
AGTC Announces Topline Interim Six-Month Data of XLRS Gene Therapy from Ongoing Phase I/II Clinical Trial
Applied Genetic Technologies Corporation (AGTC), a leading developer of gene therapies, has reported the six-month follow-up data in all patients treated with its gene therapy for X-linked retinoschisis (XLRS) in its Phase I/II clinical trial.
Nov 2, 2018 Eye On the Cure Research News
Since 1989 genetic researchers, many funded by the Foundation, have identified approximately 270 genes linked to IRDs. In most cases, defects in a single gene can cause a retinal disease and vision loss.
Sep 11, 2018 Eye On the Cure Research News
On September 4, 2018, seven researchers, including six previously funded by the Foundation, were recognized with the prestigious 2018 Antonio Champalimaud Vision Award for their contributions to the advancement of blindness-reversing RPE65 gene therapies.
Aug 15, 2018 Eye On the Cure Research News
Each recipient will receive a total of $375,000 over five years to help build an independent research program in addition to their clinical practices.
Aug 6, 2018 Eye On the Cure Research News
Seventy scientists submitted requests for funding.
Jul 20, 2018 Eye On the Cure Research News
Call to Action: Ask Congress to Support $1 Billion in Eye Research
Jul 5, 2018 Eye On the Cure Research News
Many research groups from around the world are investigating ways to create new photoreceptors from stem cells for transplantation into the retina for vision restoration.
Jun 22, 2018 Eye On the Cure Research News
Watch recorded sessions from VISIONS2018.
May 3, 2018 Eye On the Cure Research News
ARVO 2018: Dr. Stephen Daiger Reports on the State of Genetic Testing for Inherited Retinal Diseases
ARVO 2018: Dr. Stephen Daiger Reports on the State of Genetic Testing for Inherited Retinal Diseases
May 2, 2018 Eye On the Cure Research News
FFB’s own Dr. Steve Rose, chief scientific officer, reviews our commitment to funding and exploring CRISPR/Cas9 gene editing for inherited retinal disease.
Apr 25, 2018 Eye On the Cure Research News
More than 11,000 eye researchers from around the world — including five intrepid members from FFB’s science team — will gather to participate in what is essentially a massive “show and tell” of the latest scientific advancements.
Jan 17, 2018 Eye On the Cure Research News
The French biotech GenSight Biologics has received regulatory authorization in the UK to launch the PIONEER Phase 1 \ 2 clinical trial for its GS030 system — a light-sensing gene therapy (optogenetics) coupled with eyewear, which enhances visual stimulation.
Jan 9, 2018 Eye On the Cure Research News
An exciting year in fighting blindness.
Dec 20, 2017 Eye On the Cure Research News
Known as LUXTURNA™ (voretigene neparvovec), the gene therapy restored vision in a clinical trial for people between the ages of 4 and 44 with Leber congenital amaurosis (LCA) caused by mutations in the gene RPE65.
Nov 21, 2017 Eye On the Cure Research News
If a clinic is charging for a stem-cell treatment or procedure for an IRD, it is probably not legit. The expense to the patient is a major red flag.
Oct 13, 2017 Eye On the Cure Research News
FDA Committee Unanimously Recommends Approval for Spark's RPE65 Gene Therapy - Final Decision Due in January 2018
An advisory committee comprised of FDA-selected experts voted unanimously – 16 to 0 – to recommend approval.
Sep 27, 2017 Eye On the Cure Research News
In addition to funding promising biotech start-ups, the Foundation Fighting Blindness has played a critical role in developing research talent.
Jul 26, 2017 Eye On the Cure Research News
The high-tech, vision-restoring system interfaces with the visual cortex, the back of the brain where visual input is processed to create the images we see.
Jul 25, 2017 Eye On the Cure Research News
Foundation Fighting Blindness and 4D Molecular Therapeutics Partner to Boost Retinal Gene Therapy Development
The partnership will help companies and researchers quickly obtain and implement high-quality vectors for their retinal gene-therapy development efforts.
Jul 24, 2017 Eye On the Cure Research News
The Foundation Fighting Blindness has taken the translational challenge head on by investing more than $75 million in therapy-development projects with strong clinical-trial potential through its Translational Research Acceleration Program (TRAP), which includes Gund-Harrington Scholar Awards.
Jul 19, 2017 Eye On the Cure Research News
AGTC’s gene therapy uses a human-engineered virus — and adeno-associated virus or AAV — to deliver normal copies of retinoschisin to the patient’s retina.
May 23, 2017 Eye On the Cure Research News
In its fourth year, the meeting is becoming the world’s most comprehensive overview of the promising research underway for emerging IRD treatments.
May 8, 2017 Eye On the Cure Research News
How the Foundation Fighting Blindness (FFB) provided timely funding of $155,000 to help a lab at the University of California, San Diego (UCSD), leverage a $2 million retinal-gene discovery project.
Mar 22, 2017 Eye On the Cure Research News
Dr. Berson dedicated himself to clinical care and vision-saving research for people with inherited retinal diseases for five decades.
Mar 16, 2017 Eye On the Cure Research News
“…participation in a study for an emerging therapy that is not regulated by the FDA or another well-recognized regulatory agency like the European Medicines Agency in Europe, is fraught with dangers and can lead to unexpected serious consequences.”
Feb 17, 2017 Eye On the Cure Research News
Company Builds on FFB’s Initial Investment to Garner $265 Million in Therapy Development Funding
Dec 21, 2016 Eye On the Cure Research News
Improved outcome measures will make clinical trials for degenerative retinal diseases — including age-related macular degeneration (AMD), the world’s leading cause of blindness in seniors, and inherited retinal conditions such as RP and Stargardt disease — less expensive to conduct and able to deliver more precise results.
Oct 18, 2016 Eye On the Cure Research News
Understanding the pathways of the retinal neural network — and how they are rewired with aging and disease — is helpful in trying to save and restore vision.
Oct 11, 2016 Eye On the Cure Research News
Dr. Shinya Yamanka discussed his early clinical trial for iPSC-derived retinal pigment epithelial (RPE) cells for a 78-year-old woman with advanced wet age-related macular degeneration (AMD).
Oct 6, 2016 Eye On the Cure Research News
The complex and elusive nature of these conditions can also extend to the way they are passed down in families, making diagnosis and prognosis quite challenging.
Aug 18, 2016 Eye On the Cure Research News
RetroSense’s optogenetic therapy is designed to restore vision to people who are completely blind from retinal degenerative diseases such as retinitis pigmentosa by bestowing light sensitivity to retinal ganglion cells, which survive after photoreceptors, the cells that make vision possible, are lost.
Aug 2, 2016 Eye On the Cure Research News
Both approaches show strong, near-term potential for providing meaningful vision to people who are otherwise blind from retinal diseases such as retinitis pigmentosa and age-related macular degeneration (AMD).
Jul 1, 2016 Eye On the Cure Research News
VISIONS 2016 — Dr. Shomi Bhattacharya Wins FFB Award for Gaining an Understanding of Variations in Vision Loss
At VISIONS 2016, FFB’s national conference, the Foundation honored him with its Ed Gollob Board of Directors Award for breakthrough research conducted within the past year.
Jul 1, 2016 Eye On the Cure Research News
VISIONS 2016 - Dr. Richard Weleber Receives FFB's Highest Research Honor, Recognized in Touching Video
Dr. Weleber became the 10th recipient of the Foundation’s highest honor, named after FFB co-founder Lulie Gund, during the opening lunch of the VISIONS 2016 conference.
Jun 24, 2016 Eye On the Cure Research News
Subretinal injection is the most common form of delivery for gene therapies currently in clinical trials.
Oct 8, 2015 Eye On the Cure Research News
Jun 27, 2015 Eye On the Cure Research News
For those of us supporting the drive for vision-saving treatments and cures, he’s exactly the type of person we want on our team.
Jun 26, 2015 Eye On the Cure Research News
Dr. Boye received the Foundation’s Board of Director’s Award, which was presented at VISIONS 2015, FFB’s annual conference, for achievements in retinal research.
May 19, 2015 Eye On the Cure Research News
The mission of the program—to regenerate the neurons and neural connections in the eye and visual system—is synonymous with the Foundation’s mission to eradicate retinal diseases.
May 12, 2015 Eye On the Cure Research News
One of the hot topics at ARVO this year is a rapidly advancing gene-therapy approach called clustered regularly interspaced short palindromic repeats, or CRISPR.
Aug 1, 2014 Eye On the Cure Research News
An innovative genetic-engineering approach called “directed evolution” to find optimal gene-delivery systems based on adeno-associated viruses (AAVs).
Jun 21, 2014 Eye On the Cure Research News
Dr. Boye and her research team received a $900,000 grant for a gene therapy project targeting Leber congenital amaurosis.
Jun 21, 2014 Eye On the Cure Research News
The powerful and secure system enables patients to keep track of their clinical care and vision changes. At the same time, it enables scientists to search the “de-identified” (i.e., anonymous) patient information to study conditions and identify targets for treatments, preventions and cures.
May 8, 2014 Eye On the Cure Research News
Simply put, they’re creating therapies that can save vision in as many people as possible, independent of the genetic cause of disease.
Apr 8, 2014 Eye On the Cure Research News
Non-24 is a very rare condition affecting many (but not all) people who are totally blind and have absolutely no light perception. Their circadian clocks become out of sync as a result.
Dec 31, 2013 Eye On the Cure Research News
The French retinal implant developer Pixium quietly launched a clinical trial for its Intelligent Retinal Implant System 1 (IRIS1) in France, Austria and Germany.
Jul 26, 2013 Eye On the Cure Research News
Identifying the genes and proteins that play a major role in retinal health and vision is an important step in finding preventions and cures for degenerative diseases.
Jun 12, 2013 Eye On the Cure Research News
Many registries enable patients to collect and track information about their health, so they can take an active role in managing their care.
May 10, 2013 Eye On the Cure Research News
There’s hope for retinal regeneration for humans, thanks to Foundation-funded researcher Dr. Thomas Reh, who is investigating how to derive new photoreceptors from retinal cells called Muller glia.
May 7, 2013 Eye On the Cure Research News
The goal, “to regenerate the neurons and neural connections in the eye and visual system,” is exactly what people with retinal diseases need to save and restore their vision.
Apr 30, 2013 Eye On the Cure Research News
A profile on Dr. Robert Langer, a medical researcher who has received dozens of awards, accolades and honorary degrees, including, recently, FFB’s Visionary Award.
Apr 17, 2013 Eye On the Cure Research News
Mar 8, 2013 Science Education
Sometimes, saving vision simply comes down to keeping retinal cells alive, or at least slowing their degeneration.
Feb 18, 2013 Eye On the Cure Research News
More good news about treatments and technological advances for restoring vision for people with retinal diseases.
Jun 19, 2012 Eye On the Cure Research News
How do you know if a treatment is legit? There should be preclinical and clinical trial data published in a peer-reviewed journal on research for the treatment.