Writing in the Telegraph, Science Correspondent Richard Alleyne examines what autism is.

Affecting about 1pc of children and adults, and mostly males, autism covers a group of conditions known as autism spectrum disorders (ASDs) that can vary from very mild where the person can function in much the same way as those around them to severe where those affected are unable to take part in normal society.

Autism is believed to be triggered as a result of a “complex genetic jigsaw”, leaving those who suffer from it with an impaired ability to communicate and interact socially and with narrowly focused attention.

Repetitive behaviour is one of the classic hallmarks of autism.

Yet identifying the pieces of this genetic jigsaw remains difficult.

Doctors think it is likely that autism occurs when a small number of genes interact in a specific way, possibly linked to some external event or factor.

It is also not known what effect the environment has on those suffering from autism.

That said, early and intensive treatment is known to help alleviate some or all symptoms pointing to the importance of an early diagnosis.

However, this diagnosis is difficult, often relying on waiting for symptoms to develop, by which time damage has been done.

Children are presently diagnosed through lengthy tests exploring social interaction and communication skills but a simple genetic test could see those at risk diagnosed soon after they are born.

With intensive therapy started early, some believe that this can almost alleviate symptoms by adulthood.