Is autism genetic? Is it caused by a mix of genes?
A genetic detective has uncovered the genes involved in a rare disorder that affects more than 1.4 million Australians, including those with autism.
The new research suggests that people with the disorder can inherit two of the genes from their parents and one from their grandparents.
Dr Elizabeth Rousset, from the University of Sydney, said it was likely the disorder, which affects about 500,000 Australians, was caused by some combination of genes from both parents and grandparents.
“It’s very interesting that we can find two of these genes, one from each parent, and one is inherited from one of their grandparents, so we can then look at whether the genetic change is from a mix, or from one gene,” Dr RousSET said.
Dr RousSet said the finding could help scientists to identify genes that may have an impact on people with autism, including genes involved with brain development and immune function.
“This is the first time that we have been able to look at the relationship between these two genes and the condition of autism,” she said.
“We found that the two genes, when combined, are responsible for the very common condition of autistic spectrum disorder, but we also discovered that they also affect other aspects of the brain that are very important for learning and social interactions.”
The research was published online in the journal Nature Genetics.
Dr Ruth O’Brien, from Curtin University, said the findings suggested there was “more than a simple one-to-one genetic connection” between autism and genes.
“Our understanding of autism is very limited and there is some genetic overlap between autistic spectrum disorders and other developmental disorders,” she told ABC Radio Canberra.
“The problem is, if we do find genes that are involved in autism, we might be able to understand why these genes are involved and what mechanisms they are involved with.”
Dr O’Briens study involved analysing the genomes of 622 people with a range of autism spectrum disorders, and found that they were all descended from one parent with the condition.
“They have both inherited the two common autism genes, so they’re all related,” she explained.
“In terms of how that genetic information gets into the brain, there are a couple of ways in which it could happen.”
The researchers used a method known as genome sequencing to map genes involved, which involved identifying and sequencing the DNA of each individual, and then using that information to create a map of the person’s genes.
Dr O’tsset said the results suggested the two parents had been “mixed up”.
“This suggests that they’re both involved, and that they could potentially have different genetic components, but not one or the other.”
Dr Roulston said her research had revealed that a third of Australians with autism spectrum disorder had at least one genetic mutation.
“These findings highlight the need to look more closely at these mutations and the ways that they can contribute to autism spectrum conditions, and to make sure that there’s no other potential risk factors for autism,” Dr O’Tsset explained.
Topics:autism,diseases-and-disorders,dna,biotechnology,biomedical-informatics,genetics—research,genetic-research,biomed-research-and/or-pharmacology,sciences,science-and,medical-researching,australiaMore stories from Northern Territory