Scientists have moved closer to a breakthrough in ‘personalised’ treatments for a leading cause of blindness.
Researchers have stepped up their bid to create individual gene therapies for one of the factors that triggers inherited vision loss.
They used ‘induced’ stem cells – taken from ordinary skin cells – to investigate patient-specific causes of the degenerative eye disease retinitis pigmentosa (RP), which leads to blindness or severe visual impairment.
By testing retinal cells created from the stem cells in the laboratory, they linked RP in two patients to mutations in a gene called MFRP.
The scientists then used a virus to deliver normal copies of the gene into the retinal cells and restore their function.
In further experiments, the gene therapy was used to rescue the vision of genetically modified mice with RP caused by the same problem.
Lead scientist Professor Stephen Tsang, from Columbia University in New York said: ‘The use of patient-specific cell lines for testing the efficacy of gene therapy to precisely correct a patient’s genetic deficiency provides yet another tool for advancing the field of personalised medicine.’
More than 60 different genes have been linked to RP, making it a difficult disease to study.
Symptoms typically begin with night blindness after which peripheral vision is lost.
As the condition progresses, photoreceptors in the macula, which is responsible for fine central vision, are destroyed.
Professor Tsang’s team used induced pluripotent stem (iPS) cells in their research.
These are ordinary adult cells that have had their genetic clock re-set, causing them to revert to a basic embryonic stem cell-like state.
They are ‘pluripotent’ meaning that they can be transformed into a wide array of different cell types.
He added: ‘Through genome-sequencing studies, hundreds of novel genetic spelling mistakes have been associated with RP.
‘But until now, we’ve had very few ways to find out whether these actually cause the disease.
‘In principle, iPS cells can help us determine whether these genes do, in fact, cause RP, understand their function, and, ultimately, develop personalised treatments.’
The research appears in the online edition of the journal Molecular Therapy.
