A Hadassah Medical Center team has identified the genetic cause of a retinal disease that has plagued certain Israeli and Palestinian families for generations.

The findings, printed in the Archives of Ophthalmology, describe specific mutations in a gene that create a wide range of retinal phenotypes.

“Over the last six years, we have mounted a major effort to better characterize patients in Israel with hereditary retinal degenerations, with emphasis on identifying the causative genes,” relate Dr. Eyal Banin, head of Hadassah’s Center for Retinal and Macular Degeneration, and Dr. Dror Sharon, head of Hadassah’s Ocular Molecular Genetics Lab.  “We recruited patients from Israel and the Palestinian Authority with inherited retinal diseases,” Dr. Sharon says. “There are 30 to 40 types of retinal diseases and there are 180 to 200 different genes with thousands of mutations, which makes analysis immensely complicated.” Using specific genetic methodology, however, they were able to identify a single mutation that caused six families from the same village with a history of marrying among themselves to have a particular type of retinal disease. The retinal phenotype which characterized their disease was exclusively found in their village.

Dr. Banin and Dr. Sharon are now turning their attention to other diseases that occur in larger populations. As they explain: “We are examining diseases common to different ethnic groups and offering our patients the opportunity to participate in a genetic study that involves isolating the DNA from their blood samples and looking for the aberrant gene.” At this point, they have built a database of over 800 families with thousands of patients and they are beginning to identify patterns.

“Many of these patients suffer from diseases about which little was known and, consequently, they were somewhat neglected,” Dr. Banin says. “Identifying the causative genes is a significant step forward,” he notes, “and perhaps even more important, is the fact that these patients and families now have a home and an address to which to turn. That address is Hadassah.”