Studies have shown that among identical twins, if one child has an ASD, then the other will be affected about 60-96% of the time. In non-identical twins, if one child has an ASD, then the other is affected about 0-24% of the time. Parents who have a child with an ASD have a 2%–8% chance of having a second child who is also affected.
It is estimated that about 10% of children with an ASD have an identifiable genetic, neurologic or metabolic disorder, such as fragile X or Down syndrome. As we learn more about genetics, the number of children with an ASD and an identifiable genetic condition will likely increase.
A report published by CDC in 2009, shows that 30-51% (41% on average) of the children who had an ASD also had an Intellectual Disability (intelligence quotient <=70).
Intelligence quotient (IQ) of children aged 8 years with an autism spectrum disorder (ASD) for whom psychometric test data were available,* by site and sex (IQ) score-Autism and Developmental Disabilities Monitoring Network, 11 sites, United States, 2006
Center For Disease Control and Prevention
1 in 88 children in the United States are on the Autism Spectrum.
ASDs are reported to occur in all racial, ethnic, and socioeconomic groups, yet are on average 4 to 5 times more likely to occur in boys than in girls. However, we need more information on some less studied populations and regions around the world.
Studies in Asia, Europe, and North America have identified individuals with an ASD with an approximate prevalence of 0.6% to over 1%. A recent study in South Korea reported a prevalence of 2.6%
Approximately 13% of children have a developmental disability, ranging from mild disabilities such as speech and language impairments to serious developmental disabilities, such as intellectual disabilities, cerebral palsy, and autism.
Learn more about prevalence of ASDs »
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