Given current epidemiologic estimates, there are approximately 1.7 million individuals with autism in India. The primary objective of this research project is to assess the screening and diagnostic prevalence of neurodevelopmental disorders, including autism, in children between the ages of 2-9 in India and gain information on risk factors in these children. The investigators will develop a novel neurodevelopmental disability screening tool and consensus clinical criteria, and validate these instruments so that they can be used in as a diagnostic instrument for further evaluation of the prevalence of autism in this country. In addition to studying the prevalence of autism in India, the investigators will also identify the full clinical spectrum of autism using their test instruments. Furthermore, potential risk factors for autism, including infections, nutritional deficiencies and genetic factors will be identified through open ended interviews with health personnel. Not only does this study have the potential yield the first national estimate of autism prevalence in India, but also to lay the foundation for future autism research in that territory and serve as a model for international epidemiology research.