London - Scientists have detected signs of autism in babies as young as six months, leading to hopes of a test for the disorder.
They made the breakthrough by measuring brain activity and believe it could lead to identifying those infants most at risk at a much earlier stage.
Around one in 100 children develops the disorder but symptoms do not usually become apparent until the second year of life.
Earlier diagnosis, it is hoped, could lead to ways of “coaxing” the brain to develop in different ways to counter problems caused by the condition.
An estimated 600,000 children and adults in the UK are affected by autism, or autistic spectrum disorder, with genetic factors playing a role.
ASD is an umbrella term for a range of developmental disorders, including Asperger’s syndrome, which have a lifelong impact on the ability to interact socially and communicate. The latest research focused on six to ten-month-old babies with a sibling affected by the disorder.
Parents of a child with autism face a risk of almost one in five that their next child will also have the condition.
The study looked at patterns of brain activity in 54 of these “at risk” children, as well as 50 infants whose older siblings were not affected.
Sensors placed on their scalps measured brain activity via electrical signals as they were shown faces that switched from looking at them or away from them.
The intensity of the electrical activity in certain areas was diminished in children at risk of autism. This suggested they were already registering unusual patterns of eye contact and social interaction.
Researchers said 17 children in the “at risk” group were diagnosed with autism at the age of three.
Study leader Professor Mark Johnson, from Birkbeck College, University of London, said: “Our findings demonstrate, for the first time, that direct measures of brain functioning during the first year of life associate with a later diagnosis of autism, well before behavioural symptoms.
“Differences in the use of eye gaze to regulate social interaction are a well-recognised early feature in many children with autism from the second year of life. At present, it is these that will alert parents and professionals.”
But he stressed the method was not foolproof and further research was needed to refine the testing.
It would also be important to assess why some children at high risk who showed early signs of unusual responses did not develop autism, added Professor Johnson.
He said many parents wanted to know as early as possible if their children were at risk and the researchers were carrying out a pilot study targeting babies of a year old to examine potential ways of influencing behaviour.
“The brain is plastic at an early age, it should be easier to coax different pathways into doing something that leads to children having the kind of social interactions which come more naturally to other people,” said the professor.
The work was funded by the Medical Research Council and a consortium led by charity Autistica.
Christine Swabey, Autistica’s chief executive, said: “The hope is this important research will lead to improved identification.
“Ultimately, the earlier we can identify autism, the better the outcomes will be.”
Professor Christopher Kennard, from the MRC, said the study published in the journal Current Biology was “very interesting”.
It could “contribute to an earlier diagnosis for children at high risk, crucial for ensuring that they receive appropriate care,” he said. - Daily Mail