Retinologist Francine Behar-Cohen and geneticist Carlo Rivolta are developing a therapy for retinal degeneration.
Whether blue, brown or green, the eyes were the first organs to bring to light the principles of hereditary diseases and, consequently, our genetic heritage. So it is no accident that our genes and our eyeballs are now one of the most studied duos in human genetics.
In his laboratory at the Lausanne Hospital Complex, Carlo Rivolta has some of the most renowned geneticists in the field. He is the head of a laboratory tasked with finding the determining genetic factors for retinal degenerative diseases, which are difficult to screen and affect about one person out of every 3,000.
“The diseases we are studying may be caused by the alteration of over a hundred genes,” says the specialist. “We could therefore see 100 patients with the same disease without seeing common links in their DNA.” To help them, Carlo Rivolta and his colleagues currently have two approaches at their disposal: technological advances and the networking of their results thanks to the “Transvision” project set up by Francine Behar-Cohen, medical director of the Jules Gonin Eye Hospital in Lausanne.
“Transvision is a multidisciplinary network which brings together INSERM, the eye hospital and its researchers,” she says. “We also have partners from the CHUV and EPFL.” Clinicians and geneticists have their roles clearly cut out for them: the former have the job of diagnosing patients’ diseases and providing DNA samples to the latter.
“Deciphering the genome used to be an expensive and laborious task,” recalls Carlo Rivolta. “Research had to be targeted, with the hope of being lucky. Today, we can have all the information in one go.” Francine Behar-Cohen adds, “The role of clinicians has become so complicated. They have to analyse the mechanisms of diseases so as to pinpoint potential molecular targets and find common mechanisms that can make up for the absence of correlations between phenotype and genotype.” It’s a quest that has already borne its first fruits, with the identification of new genes.
And what about the future? “We will be able to develop customised therapies according to the affected gene,” says Carlo Rivolta. “As soon as we have identified all the genes that could cause the disease, we will have to find the answer to the question: what is the common mechanism whereby so many different DNA defects can cause the same disease? Once we have found this mechanism, we will also have found a potential therapeutic target for all who suffer from the disease.” It’s a long path that the “Transvision” scientists will have to tread in the years to come. “There is only one multidisciplinary network – like ours – for getting there,” says Francine Behar-Cohen.