Scientists on Thursday say they are on track to establish the genetic triggers for autism, paving the way for earlier diagnosis of children who could be at risk of developing the condition and opening up the possibility of inventing new drugs and treatments for the condition.
The identification of a range of rare genetic mutations by an international collaboration known as the Autism Genome Project, involving scientists in the US, Canada and Europe, will further undermine the arguments of those who have claimed that the MMR vaccine, against measles, mumps and rubella, is somehow to blame.
Geri Dawson of Autism Speaks, a charity that helped to fund the research, said that the findings would bring hope to many families who struggle with autism on a daily basis.
“What is critical now is to translate these basic biological findings into clinical tools for early detection and treatment.” This would allow children to be helped earlier in life. “We’re now developing behavioural interventions for infants and toddlers who are at risk for autism.”
In the largest study ever into the genetics of autism, the scientists identified rare genetic variations that were 20 per cent more frequent in children with autism than in children without the disorder.
These so-called “copy number variations” (CNVs), which can be missing chunks of DNA or extra copies of sequences in and around genes, occur in less than one in 100 people in the general population.
In the study, scientists compared the incidence of these rare CNVs in 996 people with autism spectrum disorders and in 1,287 unaffected people, all with European ancestry. The results, published in Nature, showed that some of the CNVs were inherited while others were found in children but not in their parents.
Stephen Scherer of the Hospital for Sick Children in Toronto, Canada, said that the research would lead to a paradigm shift in assessing the causes of autism. “Most people in the field believed that autistic individuals shared common genetic variations in just a few genes,” he said. But the research suggests the genetic variations are actually rare.