According to new research in the UK, autism and related disorders are possibly far more common than once thought.

Researchers at Guy’s and St Thomas’ Hospital in London say that 116 in every 10,000 children suffer from autism or autism spectrum disorders (ASD), this contradicts previous estimates of 44 per 10,000.

Study author Professor Gillian Baird, says autism and related ASD is substantially higher than previously recognized, and it is unclear whether the increase is due to better ascertainment, broadening diagnostic criteria, or increased incidence.

The cause of autism is unknown and it is a lifelong disability affecting the way that a person communicates and relates to other people.

All those with autism have impaired social interactions, communication and imagination.

ASDs are developmental disorders characterized by different degrees of impairment in communication and social skills and repetitive patterns of behaviour; the condition is more common in boys than girls and as a rule develops around 30 months of age.

The researchers calculated the new estimates by looking at cases of autism and ASDs in children aged nine and 10 in south London in 2001.

They studied children with all forms of ASD and children with special educational needs.

The study revealed 39 children per 10,000 had autism and 77 per 10,000 had ASD.

The researchers say that accurate estimates of ASD prevalence were essential for the planning of educational, social and medical services.

Professor Baird said the findings indicated that children with some form of ASD constituted 1 per cent of the child population in Britain.

Over the years a number of studies have failed to find any evidence of a suggested link to the combined MMR vaccine given to children and autism and many scientists attribute the rise to a broader definition and greater awareness of the disorder.

The study is published in The Lancet medical journal.