What is the prevalence of autism？

Autism happens to all race, culture and society, with male affected 4.5 times more frequently than female. In just 10 years, the prevalence of autism has raised from 1 in 150 to 1 in 68 children. In Hong Kong, the prevalence is around 1 in 100 children. Between 2010 and 2012 the numbers remain the same, but as suggested by the ADDM report. It is too early to say that the numbers has stopped rising. Here is a chart taken from CDC website , reporting prevalence findings of ADDM network between 2000 – 2012.

https://www.cdc.gov/ncbddd/autism/data.html

Risk Factors

Individual with ASD can be diagnosed at the age of 18 months old or younger. One should be assess immediately without delay to avoid missing the golden window for interventions, which is normally between the age of 2 to 6 years old. The following groups are at higher risk of having ASD:

Among identical twins, if one child has ASD, than chance for the other child affected is 36-95%. In the case of non-identical twins, if one child has ASD, than chance of the other child affected is 0-31%.
If the first sibling has ASD there is a 2%-18% chance the second child also has it
Children born to older parents are at a higher risk for having ASD.
Children who are born with low birth rate <2500g and prematurely <33 weeks are at greater risk for having ASD. [Read article]