Jeremy Laurance: What is Asperger's syndrome, and how has it affected Gary McKinnon's extradition? Asperger's Syndrome, sometimes called "mind blindness," lies at the milder end of the conditions known as autism spectrum disorders. It disturbs something that is core to our being human by disrupting the ability to read social situations. In the social world in which we live the capacity to read situations and respond appropriately is crucial to successful human interaction. Gary McKinnon was diagnosed with Asperger's Syndrome in 2008 by one of the world's leading authorities on the subject. Professor Simon Baron-Cohen of the Autism Research Unit at Cambridge University, along with two other experts, concluded that he matched the profile for the condition as well as suffering from depression. His mother Janis Sharp, claimed he was suicidal and would not survive being locked up in a US prison, a view backed by Professor Jeremy Turk of St George's Hospital and the Home Affairs Select Committee which called for his extradition to be halted because of his "precarious state of mental health." Autistic spectrum disorders have risen sharply in recent years leading to speculation that modern lifestyles are behind the increase. Experts say, however that there is no evidence that environmental causes cited as possible triggers, including diet, pesticides, infections, MMR vaccine, mercury and lead have any effect on the incidence of the condition. They put it down to increased awareness and detection. Classic autism, the severest kind is thought to affect 30,000 people in the UK, a figure that has remained unchanged in 50 years. However, autistic spectrum disorders of the kind suffered by Gary Mckinnon affect an estimated 500,000 people. There is no cure and though many parents of affected children believe they can be treated the results are unclear. Responding to the Home Secretary's decision not to extradite Gary McKinnon, Mark Lever, Chief Executive of The National Autistic Society, said: "We're delighted that the years of waiting are finally over for Gary and his family. "Janis" relentless campaigning for her son and Gary's stoicism in the face of some testing circumstances have been truly inspiring. People with Asperger Syndrome can be vulnerable and the NAS argued long and hard for the Home Secretary to take Gary's condition and its associated challenges into account when making this decision. A decade is a long time to wait, and those years can never be recovered but Mrs May's decision has finally put an end to a difficult chapter.