Scientists have discovered dozens of genes that are strongly linked to autism, in what could be a breakthrough. Researchers hope the more than 70 newly-identified genetic variants could pave the way for new tests and treatments for the condition.
Autism and related conditions such as Asperger’s affect more than one in 100 British children and one in 44 American youngsters — ten times more than 30 years ago.
Despite the rise, the condition is still little understood and getting a diagnosis can be lengthy and stressful for patients and their families.
Families are often forced to attend multiple hospital appointments and have children put through several psychological tests.
While drugs can be given to control symptoms such as aggression or hyperactivity, there is no cure.
In the largest study of its kind, U.S. researchers looked at the DNA of 150,000 participants, 20,000 of whom had diagnosed autism.
They identified 72 genes that are ‘very strongly’ linked to the condition and hundreds more with looser associations.
Scientists are one step closer to solving the riddle of autism after discovering more than a hundred new genes linked to the condition
It’s hoped the latest study, published in Nature Genetics, will help future research teams narrow their focus.
Study co-author Dr Joseph Buxbaum, director of the Seaver Autism Center for Research and Treatment at Mount Sinai in New York, said: ‘We know that many genes, when mutated, contribute to autism.
‘In this unprecedented study, we were able to bring together multiple types of mutations in a wide array of samples to get a much richer sense of the genes and genetic architecture involved in autism.
‘This is significant in that we now have more insights as to the biology of the brain changes that underlie autism and more potential targets for treatment.’
The study used an autism cohort involving 63,000 individuals of which 20,000 had the condition, and a developmental-delay cohort involving 91,000 people.
Statistical analysis revealed 72 genes strongly associated with autism, as well as 252 more that are very likely involved in the condition.
Genes linked to autism tended to affect mature neurons — which can no longer divide unlike other neurons and appear early in development.
For comparison, those related to developmental delays are more likely to be active during a neuron’s development, although the two can ‘overlap’.
Buxbaum said a ‘precision medicine approach’ will likely be needed for autism that is based on a person’s genes.
And people should be genetically tested for autism to help develop new medicines that ‘benefit families and individuals at risk for autism spectrum disorder’, Dr Buxbaum said.
‘The more we can advance therapeutics, based on the targets identified in these genetic findings, the more people we have the potential to help, which could have a significant impact in addressing autism and developmental delay worldwide,’ he added.
His team pooled data from autism research initiatives, such as the Autism Sequencing Consortium, as well as the Massachusetts Institute of Technology and Harvard.
They looked at the genomes of around 150,000 people, 20,627 of whom had autism.
As well as the 72 genes that appear to be behind autism, they spotted a further 250 that are also linked with the condition.
Autism refers to a broad range of conditions characterized by challenges with social skills, repetitive behaviors, speech and non-verbal communication.
What are the signs of autism?
Signs of autism in young children include:
Not responding to their name
Avoiding eye contact
Not smiling when you smile at them
Getting very upset if they do not like a certain taste, smell or sound
Repetitive movements, such as flapping their hands, flicking their fingers or rocking their body
Not talking as much as other children
Repeating the same phrases
Signs of autism in older children include:
Not seeming to understand what others are thinking or feeling
Finding it hard to say how they feel
Liking a strict daily routine and getting very upset if it changes
Having a very keen interest in certain subjects or activities
Getting very upset if you ask them to do something
Finding it hard to make friends or preferring to be on their own
Taking things very literally – for example, they may not understand phrases like ‘break a leg’
Common signs of autism in adults include:
Finding it hard to understand what others are thinking or feeling
Getting very anxious about social situations
Finding it hard to make friends or preferring to be on your own
Seeming blunt, rude or not interested in others without meaning to
Finding it hard to say how you feel
Taking things very literally – for example, you may not understand sarcasm or phrases like ‘break a leg’
Having the same routine every day and getting very anxious if it changes