The early-warning test for autism

They believe the simple test could help identify those children who need help at a much earlier age.

Half of parents whose children have autism become concerned in the first year. But often they are not taken seriously.

The disorder is not usually diagnosed until the child is three or four, say U.S. researchers.

But the 'name check' test provides highly consistent results, they say. For the study, a researcher stood behind each child and called their name.

If the child did not respond after three seconds, two more attempts would be made. All those aged one who were not at risk passed the test.

But three-quarters of those who did not respond, and were deemed at risk because of a family history of autism, went on to have developmental problems.

Dr Aparna Nadig, of the University of California Davis, Sacramento, who led the research team, said: 'Earlier identification of autism offers the possibility of early intervention, which holds the promise for improving outcomes in children with autism.'

Autism is an umbrella term for a range of developmental disorders that have a lifelong effect on someone's ability to interact socially and communicate.

There are related problems, known as autism spectrum disorders, which include Asperger's syndrome.

The report, in the Archives of Pediatrics & Adolescent Medicine, concludes that the test is easy to administer, score and takes few resources. "If a child fails to orient-to name, particularly reliably over time, this child has a high likelihood of some type of developmental abnormality and should be referred for more frequent screening."

Judith Gould, director of diagnostic unit at the National Autistic Society said it "welcomes research that can aid the identification of autism as early as possible".

"There is a great deal of evidence that early intervention can benefit the child's development." But she added: "Just because a baby does not respond to their name does not necessarily mean that he or she has autism."

In the study, 89 per cent of infants who did not have autism and 94 per cent of those without developmental problems at two years, had responded to their name on the first two calls at the age of one. Half of those later diagnosed with autism failed the test at one year. Of those with any kind of developmental delay, 39 per cent failed.