All of the following regarding Autistic spectrum disorder are true except

Ans. is 'D' i.e., More common in girls * Autism is more common in boys and among low socio-economic groups.* Onset of symptoms of infantile autism (usual form of autism) is before 2.5 - 3 years. If onset of symptoms is after 3 years, it is referred to as childhood autism.* Presently, the cause of infantile autism seems to be predominantly biological.PresentationA. Marked impairment in social interaction: - There is no social smile or eye contact. These children prefer to play alone with inanimate objects and do not like to mingle with others (do not make friends). There is lack of attachment to parents and absence of separation anxiety.B. Impairment in communication (language as well as non-verbal communication): - Delayed or absence speech, lack of verbal or facial response to sounds or voices, abnormal speech patterns, echolalia, perseveration and prominent reversal (referring to self as 'you' and to others as 'I').C. Stereotyped and restricted repetitive behavior, interests and activities:- Mannerism, Stereotype behavior (head banging, body-spinning, rocking, clapping, watching own hand.D. Other features: - Mental retardation (in 50-75% patient), epilepsy (in 25-35%), Hyperkinesis, inability to concentrate.