%J Journal of Child Psychology and Psychiatry %N 4 %V 51 %A Nurit Yirmiya %A Tony Charman %X Autism is one of the most heritable neurodevelopmental conditions and has an early onset, with symptoms being required to be present in the first 3 years of life in order to meet criteria for the ‘core’ disorder in the classification systems. As such, the focus on identifying a prodrome over the past 20 years has been on pre-clinical signs or indicators that will be present very early in life, certainly in infancy. A number of novel lines of investigation have been used to this end, including retrospective coding of home videos, prospective population screening and ‘high risk’ sibling studies; as well as the investigation of pre- and peri-natal, brain developmental and other biological factors. Whilst no single prodromal sign is expected to be present in all cases, a picture is emerging of indicative prodromal signs in infancy and initial studies are being undertaken to attempt to ameliorate the early presentation and even ‘prevent’ emergence of the full syndrome. %O The definitive version is available at www3.interscience.wiley.com %T The prodrome of autism: early behavioral and biological signs, regression, peri- and post-natal development and genetics %P 432-458 %L discovery10004444 %D 2010