Improving the view on the genetic causes of retinitis pigmentosa

The scientists also made human retinal photoreceptors derived from induced plouripotent stem cells (iPSCs) to examine the expression of REEP6 in the human retina. Credit: S. Agrawal, R. Chen, M. Cheetham and G. Arno.

Progressive development of night blindness and tunnel vision, sometimes from the early age of 2, are trademarks of retinitis pigmentosa. Being the most common inherited disorder of the retina, retinitis pigmentosa affects nearly 1 in 4,000 people. More than 1 million are visually impaired around the world due to this untreatable disease.

A number of genes have been associated with this condition. Fifty-eight are inherited in a Mendelian autosomal-recessive manner, while a number of genes are passed following an autosomal-dominant or X-linked mode of inheritance. However, these genes do not explain about 40 percent of the cases.
Doctorate student Smriti Agrawal, a co-first author of this study, and her mentor, co-senior author Dr. Rui Chen, associate professor of molecular and human genetics at Baylor College of Medicine, together with colleagues from other institutions in the U.K., California and Maryland have found that mutations in REEP6—a gene that until now had not been associated with a human disease—can explain some of the cases that lacked a genetic diagnosis.
This discovery was the result of a long-term collaboration, which began when Agrawal’s abstract at the renowned ARVO meeting of vision specialists caught the attention of researchers at University College London, who also study retinitis pigmentosa.
“We had discovered four families affected with this novel REEP6-associated retinitis pigmentosa in our patients and had begun preparing a manuscript when we read the abstract Rui Chen’s lab had sent to the 2016 ARVO meeting,” said co-senior author Dr. Michael Cheetham, professor of molecular and cell biology in the Institute of Ophthalmology at University College London. “When we learned that the Chen lab had a similar family and had developed mouse models with REEP6 mutations, we contacted Chen to discuss joining forces and collaborating.”
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Source: Medical Xpress