How Much Do We Really Know about the Causes and Incidence of Autism? ; the Big Question
Jeremy Laurance Health Editor, The Independent (London, England)
Why is autism in the news again?
The developmental disorder characterised by "extreme autistic loneliness" and "an obsessional desire for the maintenance of sameness", according to Leo Kanner, who first described it in 1943, exerts a grip on the public imagination like no other.
Research published this week suggested men over 40 were six times more likely to father a child with autism compared with men under 30. The study, published in Archives of General Psychiatry, involved more than 130,000 children in Israel, and is one of the first to suggest that men may be subject to the same biological clock that increases the risk of birth abnormalities in women as they age.
The research showed ageing in men had a linear effect, with the risk of fathering a child with autism doubling every 10 years. However, the team found no link with the age of the mother.
What does this tell us about autism?
Two things - possibly. First, it suggests one factor contributing to the widely reported rise in autism could be the trend to later parenthood - in particular later fatherhood.
Second, it adds to evidence that genetic factors are a key cause of autism. The researchers, who included a team from the Institute of Psychiatry at Kings College, London, say spontaneous mutations in sperm-producing cells, or discrepancies in how genes are expressed, may account for the increased incidence with older fathers.
Why so much interest in autism?
In the social world in which we live, the capacity to read situations and respond appropriately is crucial to success and can mean the difference between popularity and loneliness. Autism disturbs something that is core to our being human.
Some suggest that the greater public interest in autism compared with other disorders such as Down syndrome occurs because sufferers look "normal" and are hence easier to identify with.
Interest in autism and its causes has been fuelled in recent years by the controversy over MMR vaccine after research by Andrew Wakefield published in The Lancet in 1998 suggested it could be linked with autism and bowel disease. The research has since been largely discredited but the controversy has continued.
Is autism increasing?
Yes and no. A disorder characterised by an "inability to read social situations" is not simple to diagnose. In some people, autism is disguised by high intelligence and may go unrecognised throughout their lives. Experts now refer to autistic spectrum disorders to include those less severely affected and over the decades this elastic definition has stretched to include increasing numbers of people.
Classic autism, the severest kind, is thought to affect 30,000 people in the UK, about five in every 10,000, a figure that has remained largely unchanged in 50 years. However, more than 500,000 are estimated to be suffering from autistic spectrum disorders including Asperger's syndrome, a mild version of autism, sometimes called "mind blindness". Of these around a fifth are people with a low IQ and who need support, and four fifths are of average or high IQ and are mildly affected, according to the National Autistic Society.
Most experts say that because autism includes a spectrum of disorders with no clear boundaries, the apparent rise in cases is due to growing awareness and shifts in diagnosis. Nevertheless many believe there is an underlying real rise in the condition.
What causes it? …
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Publication information: Article title: How Much Do We Really Know about the Causes and Incidence of Autism? ; the Big Question. Contributors: Jeremy Laurance Health Editor - Author. Newspaper title: The Independent (London, England). Publication date: September 6, 2006. Page number: 31. © 2009 The Independent - London. Provided by ProQuest LLC. All Rights Reserved.