Worldwide search for autism genes begins

An international team of 170 scientists has embarked on a search for genes that influence a child's risk of developing autism. The project will study 6000 DNA samples from around 1,200 families affected by the developmental disorder, in order to track down the estimated 15-20 genes thought to be involved. The scientists will use DNA 'chips', or microarrays, to look at 10,000 different genetic variations at the same time, to pinpoint those associated with autism. All the families taking part in the study have at least two children with autism, or a related disorder such as Asperger's syndrome.

Results from the new project, funded by the US National Alliance for Autism Research (NAAR), should be available in early 2005. 'We are very excited about combining scientific expertise with this cutting-edge technology to help uncover the genetic underpinnings of autism and determine what causes the disorder', said Prisca Chen Marvin of NAAR. She said the work was important for the diagnosis, treatment and management of the disorder. The number of children diagnosed with autism has increased dramatically in recent years, an increase partly attributed to better recognition of the condition.

Although autism often affects more than one child in the same family, suggesting that genetic factors are important, several non-genetic factors are also likely to be involved. A new UK study aims to identify these environmental influences, by studying 14,000 children who have been followed since birth. The Avon Longitudinal Study of Parents and Children (ALSPAC), also known as the 'Children of the 90s' project, has recently been awarded £400,000 by the Medical Research Council to look at autism.

Paul Shattock, of the Autism Research Unit in Sunderland, welcomed the funding: 'There's a whole range of possible environmental triggers, and given the size of this study, they should be able to tease out which ones are significant', he told the Scientist magazine. He added that he was 'pleased they're moving away from a totally genetic grounding to consider environmental factors'. ALSPAC team leader Jean Golding said the research would also help define Asperger's syndrome and autism. 'What this research is doing, that previous work hasn't, is try and untangle the different traits', she said.