WCXX

His social isolation and the fact he finds it difficult to make friends also point to the fact that Arthur Conan Doyle's character could suffer with some form of autism, and Saga Noren, played by Sofia Helin in the BBC 4 crime drama, shares many of the detectives traits, the society say.

David Neilson, who plays Roy Cropper, has in the past admitted to acting as though his character has Asperger's syndrome, although it is never mentioned in the series.

Ms Steward, 27, who has Asperger's, added: "There is a real misunderstanding of people who are on the spectrum, and if Sherlock was a real person and people met him they might be scared of him because he is different.

"The great thing about Sherlock is that he is using his traits as a person potentially on the spectrum to do something positive and he is achieving something.

"I think that the other important thing is that Sherlock doesn't see himself as disabled. People on the spectrum are just people, they might have a few different traits, and they might find some things more difficult, but they are still a human being first and foremost."

Carol Povey, director of the centre for autism at the NAS, said more needs to be done to represent people who have autism across the spectrum, as it affects one in 100 people in the UK.

She said: "It is really good for society to show that we are accepting difference, we are not all striving to be one type of person, actually society is made up of a wonderfully wide variety of people and it is fantastic to see that in the characters."

But because autism affects so many lives, to truly represent society more people with the condition, on all ranges of the spectrum, should be represented on screen, she said.

Praising the way Sherlock uses his autistic traits, she added: "The more we can see people on the autism spectrum not only getting by but actually contributing to society in a really positive way the better."