et al., 2004). Clinicians and researchers have achieved consensus on the validity of autism as a diagnostic category and many features central to its definition. It is somewhat surprising and very encouraging to note that, as greater consensus has been achieved on the definition of strictly defined autism, an interesting and helpful discussion on issues of broader phenotype or potential variants of autism has begun.
Today, there is a broad agreement that autism is a developmental disorder, and autism and associated disorders in the spectrum represent the behavioural manifestations of underlying dysfunction in the functioning of the central nervous system (Minshew, N.J. and Williams, D.L., 2007). Within this, it can also be included that sustained educational and behavioural interventions are useful and constitute the core treatment of such condition (Klin, A., Jones, W., Schultz, R., Volkmar, F., and Cohen, D., 2002). In 1943, Kanner's seminal clinical description of 11 children with "autistic disturbances of affective contact" has endured till date. His description of autism was grounded in data and theory of child development. Children those are normal exhibit marked interest in social interaction from early in life (Kanner, L., 1946). Kanner suggested that early infantile autism is an inborn, constitutional disorder in which children are born lacking the typical motivation for social interaction and affective comments. He used the model of inborn errors of metabolism to explain that individuals with autism are born without the biological preconditions for psychologically metabolizing the social world. The term autism was borrowed from Bleuler who first used autism to describe idiosyncratic, self-centered thinking (Bleuler, M., 1979). Kanner used this term to suggest that autistic children too live in their own world. It represents a failure of development and fantasy is impoverished if present at all (Kanner, L., 1951).
In addition to the remarkable social failure, the one of the other features that may be present in such individuals is profound disturbance of communication to the extent that some of them may be mute (Nacewicz, B.M. et al., 2006). The language disturbance in others may be marked by echolalia and literalness as well as a fascinating difficulty with acquiring the use of the first person, personal pronoun, "I." These children, therefore, refer to themselves in the third person, "he" or by first name. Another intriguing feature is the children's unusual responses to intimate environment. This can be exemplified by unresponsiveness to parents, yet over-sensitiveness to the small changes in daily routine or simply environmental sounds. The three prime criteria enumerated by Kanner still hold good, and they are to date used to define autism. These are unusual social isolation, resistance to change, and dysfunction in communication (Landa, R.J., Holman, K.C., and Garrett-Mayer, E., 2007).
It has now been recognised that parental behaviour as such plays no role in pathogenesis of autism. It is now known that children with autism are found in families of all social classes, and more recent data and rigorous research have failed to demonstrate association with social classes (Stone, W.L., McMahon,