Australians find cause of incurable rare eye disease

Macular Telangiectasia type 2, or MacTel, is incurable and affects between 500-1,200 Australians, with symptoms usually beginning after the age of 40.The debilitating disease begins with patients experiencing a loss of central vision crucial for tasks requiring focus – such as driving or reading – and can eventually lead to blindness.{{quote-A:R-W:450-I:2-Q: These five genetic risk loci are our ‘treasure map’, telling us where to ‘keep digging’ in order to discover the specific genes implicated in MacTel. -WHO:Professor Melanie Bahlo, Statistical genetecist}}However, now that scientists have identified its cause, there is hope they will be able to use that information to better understand the disease and look for ways to prevent or stop its progression.The team’s findings, published in Nature Genetics, established five key regions – or loci – in the genome most likely to influence a person’s risk of developing MacTel.Professor Melanie Bahlo, who co-led the study with Dr Thomas Scerri, said the study involved detailed genetic analysis of MacTel patients from around the world, including Australia, using genome wide association studies.“We analysed more than six million genetic markers and identified five loci across the genome that had similar patterns in people with the disease, but not in the healthy individuals,” Bahlo said.“These five genetic risk loci are our ‘treasure map’, telling us where to ‘keep digging’ in order to discover the specific genes implicated in MacTel.”{{image3-a:l-w:400}}The analysis also revealed people with the MacTel genetic risk loci identified in the study had changes in their metabolism, specifically in their glycine and serine levels.Bahlo said this meant there could be a significant relationship between the level of glycine and serine in the body, and onset of the disease.“Though the exact link between the disease and glycine and serine is yet to be confirmed, the connection is an exciting clue to help us further explore metabolic abnormalities in people with MacTel,” she said.