Page URL:

New study provides more genetic clues to autism

3 May 2009
Appeared in BioNews 506

New research, led by Professor Hakon Hakonarson from the Children's Hospital of Philadelphia and published in the journal Nature, has identified for the first time common genetic variations that could explain 15 per cent of autism cases.

Several genes have been previously linked to autism, but these are rare and only account for a small number of autism cases. To search for common variants, researchers scanned the DNA of 3,100 people from 780 American families with two or more children with autism and then replicated the results by studying an additional 1,200 affected and 6,500 unaffected people.

Six variations that increase the risk of autism were discovered, all of which are located on chromosome 5 between two genes, CDH10 and CDH9. These genes code for proteins called cell adhesion molecules, which are important in making connections and communication between brain cells. One of the variations identified occurs in more than 65 per cent of cases - although the scientists estimate it only plays a major role in about 15 per cent, and that other, unknown factors are more important in the remainder.

Professor Hakonarson said: 'Because other autism researchers have made intriguing suggestions that autism arises from abnormal connections among brain cells during early development, it is very compelling to find evidence that mutations in genes involved in brain interconnections increase a child's risk of autism', adding 'there are going to be many genes involved in causing autism'.

Another study, published at the same time in the journal Molecular Psychiatry and led by Professor Tony Monaco from the Wellcome Trust Centre for Human Genetics in Oxford, UK, has also identified a link between a gene important for growth and development of brain cells and autism.

Professor Simon Baron-Cohen, from the autism research centre at the University of Cambridge, UK, said that there are now 133 genes linked to autism. He said 'The challenge for future research will be to establish which aspects of autism they can explain, how many of these genes are necessary and sufficient to cause autism and how they may interact with environmental factors'.

Autism relates to autism spectrum disorders, which involve traits such as communication and social interaction difficulties, narrow interests and repetitive behaviour. It affects about 1 in 150 children and is more commonly seen in boys.

Biggest autism study identifies gene variations behind condition
The Times |  29 April 2009
Genes 'have key role in autism'
BBC News Online |  28 April 2009
Gene variant found in 65% of autism cases
New Scientist |  28 April 2009
13 June 2011 - by Dr Lux Fatimathas 
American researchers have linked hundreds of spontaneous genetic mutations to the group of psychological syndromes called autism spectrum disorders (ASDs)...
31 May 2011 - by Mehmet Fidanboylu 
Gene activity in two brain regions is different in autism, scientists say. A US study found activity patterns were similar in the frontal and temporal lobes of people with autism, despite the lobes having different functions...
23 October 2009 - by Sandy Starr 
The Progress Educational Trust (PET) debate 'From Autism to Asperger's: Disentangling the Genetics and Sociology of the Autistic Spectrum' took place in the UK Houses of Parliament on the evening of 20 October 2009, two days before the Autism Bill received its third and final reading in the House of Lords....
18 October 2009 - by Dr Marianne Kennedy 
A large genetic study has uncovered a single 'letter' change in DNA which is associated with autism. The multi-national collaborative team, who published their findings in Nature, also identified two further regions of the genome which could contain other rarer genetic changes that have an even greater influence on the condition. Coinciding with these discoveries and publishing their findings in the Proceedings of the National Academy of Sciences, a team led by Pro...
21 September 2009 - by Professor Richard Ashcroft 
Autism spectrum disorder (ASD) is rarely far from the news. ASD is a complex, and as yet poorly understood, pervasive developmental disorder. People with ASD display a triad of impairments in social communication, social interaction, and social imagination (1). The impact of these impairments on children and adults with ASD, and on their families, can vary enormously. However, a common reaction to ASD is fear: fear that my child may develop ASD; fear that my child with ASD will suffer;
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.