Researchers from the University of Manchester and the Central Manchester Health Care Trust have developed a blood test that may improve treatment for congenital cataracts in children.
Testing for mutations in a child’s DNA previously required scientists to comb through each mutation individually. The new test promises to collect data on all mutations simultaneously with only one blood test, something that the researchers say could revolutionize the way cataracts are diagnosed as a standalone condition and as symptoms of greater complications, such as Warburg micro syndrome and galactokinase deficiency.
"At the moment, screening for one gene takes around four weeks. There are more than 100 known genes linked to congenital cataracts, so establishing the cause by screening genes individually can sometimes take years," said Rachel Gillespie, who developed the test and delivered the team’s findings at the recent British Society for Genetic Medicine conference.
"Our test looks at all of these genes in parallel,” she added, “so patients can be diagnosed much faster and receive the treatment, clinical management and genetic counseling they need."
Cataracts are classified as an overall clouding of the eye’s lens. The condition is the leading cause of blindness worldwide, according to the Centers for Disease Control and Prevention. Congenital cataracts are uncommon — an estimated 200 children are born with the condition each year, with 200,000 affected worldwide — but they are easy to treat in newborns. Harder to understand are the cataract’s causes. Both genetics and environmental factors during pregnancy can affect a newborn’s vision.
"Diagnosing a congenital cataract is very easy at birth, but diagnosing the cause takes considerably longer," Professor Graeme Black, from the University of Manchester, told the BBC. "If you have a child with no family history then finding the cause can take months or years.”
The new test has hopes to better diagnose cataracts using next-generation sequencing, a process used for looking at DNA in parallel, instead of reading each mutation one by one. The process takes far less time, which makes it more efficient economically.
"Using next-generation sequencing, we are now able to identify the cause of cataracts in children in a way that is much faster and more cost-effective than the current method," Gillespie said.
Hospitals in Manchester will begin offering the test in December. According to the National Health Service in Britain, congenital cataracts often come in children whose families have no prior history of cataracts. Cataract-removal surgery can offer the chance to remove the cloudy lens and replace it with an artificial lens.
"Any development which enables children to be diagnosed quicker and gain faster access to treatment is a welcome step forward,” said Steve Winyard, from the Royal National Institute for Blind People. "It will be exciting to watch how this research progresses and how the genetic information might be used to manage congenital cataracts in the future."