Scientists find gene for leading cause of blindness
Icelandic and Swedish scientists have discovered two common ‘single letter’ variations in a gene called LOXL1 that appear to account for 99 per cent of cases of so-called exfoliative glaucoma (XFG), the UK’s leading cause of blindness in over 40s.
Study leader Kari Stefansson, certified Neurologist and Chief Executive of the Icelandic company deCODE Genetics, believes that the finding offers hope for more efficient diagnosis and treatment of the condition. ‘This discovery is remarkable and important because the genetics has led us directly to what appears to be the sole cause of a devastating common disease. The risk conferred by these variants is such that it accounts for virtually all cases of exfoliation glaucoma, meaning that if we can neutralize the impact of these variants we might eliminate the disease’, he said.
Everyone inherits two versions of each of the estimated 25,000 human genes, one from their mother, and one from their father. The researchers found that a person’s risk of developing glaucoma depended on whether they had inherited a single or a double dose of a LOXL1 gene associated with an increased risk. Depending on which version they inherited, people who have one dose of a harmful LOXL1 gene are either 26 or 8 times more likely to develop XFG, and have more than triple those risks if they inherit a ‘double dose’ say the researchers.
Stefansson and his team are planning further studies to find out how new drugs might be developed to target the LOXL1 gene. They aim to have a diagnostic gene test on the market “before the end of the year”.
Sources:
Genetic Cause of Form of Glaucoma Identified
http://www.washingtonpost.com/wp-dyn/content/article/2007/08/09/AR2007080900966.html
http://www.washingtonpost.com/wp-dyn/content/article/2007/08/09/AR2007080900966.html
Common Sequence Variants in the LOXL1 Gene Confer Susceptibility to Exfoliation Glaucoma
http://www.sciencemag.org/cgi/content/abstract/1146554