An international consortium involving Australian researchers has identified two genes that cause the rare ocular condition macular telangiectasia type 2 (MacTel 2).
The first of its kind research, published last week in the New England Journal of Medicine, has linked low levels of the amino acid serine to the disease. This leads to a build up of a toxic lipid in the retina and causes the death of photoreceptor cells.
MacTel 2 is currently an untreatable eye disease that causes loss of central vision, and affects two million people worldwide, including 150,000 Australians. The researchers also discovered a link between MacTel 2 and a rare peripheral neuropathy, known as HSAN1, which causes severe weakness and numbness in the hands and feet, determined by variants in the same two genes.
Professor Martin Friedlander, president of the Lowy Medical Research Institute (LMRI) and professor at Scripps Medical Institute, led the 15-year research project, which involved a mix of scientists and clinicians from the US, UK and Australia.
Professor Robyn Guymer, from the Centre for Eye Research Australia, has been part of the consortium since its foundation, while several local patients with MacTel 2 and HSAN 1 also participated in the study.
“This study has been the result of a unique, multifaceted international effort from scientists and clinicians, using astute clinical observation along with clues from genetics and metabolomics,’’ she said.
“One of the first clues came from the clinical teams, who noticed that there were people with both the rare eye disease MacTel and also the rare peripheral neuropathy. This then set the direction of research that lead to this discovery.’’
Guymer said the discovery raised hopes of developing treatments that could be taken to clinical trial.
“This international research effort would not be possible without the generosity of the Lowy Medical Research Institute. It brings hope of trialling treatments for a disease which up to now has been considered untreatable,” she said.
Other Australians involved in the study included Professor Mark Gillies, from the University of Sydney, also an original member of the consortium, and Professor Melanie Bahlo, from the Walter and Eliza Hall Institute of Medical Research, who conducted many of the genetic studies.Dr Mali Okada, medical retina specialist at The Royal Victorian Eye and Ear Hospital, worked with the Melbourne clinical teams as well as the team in London, while PhD student Roberto Bonelli was one of Bahlo’s team.
The LMRI, Australian National Health and Medical Research Council, National Eye Institute (US), National Institutes of Health (US) and National Science Foundation (US) funded the research.
