Autism

Autism is a developmental disorder of unknown origin. Once considered rare and almost always severe, it is now understood to be more common and varied in its occurrence. Autism begins in infancy, affecting one in 200 children. Usually detected by the age of three and in some cases as early as 18 months,¹ rates of occurrence are unequally divided between the sexes with it being four times more likely to manifest in boys than girls.

Autism is characterized by impairments in socialization, communication, and behaviour and play. Children affected with this disorder “demonstrate deficits in 1) social interaction, 2) verbal and nonverbal communication, and 3) repetitive behaviours or interests. In addition, they will often have unusual responses to sensory experiences, such as certain sounds or the way objects look”.¹ The cognitive abilities of individuals with autism vary widely. While the rate of mental retardation in autism is approximately 70%, a significant percentage of individuals fall within the average to above-average range of intelligence. Between 15% and 30% of autistic children experience a period of regression at the age of 12 to 20 months in speech and social behaviour.

While no susceptibility gene has yet been identified, evidence of inheritability exists. The recurrence rate of autism in siblings is known to be between 2% and 8% and milder impairments of social communication skills or language are found in as many as 20% of relatives.

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