Helpful Facts & Statistics About 1 in 68 children have been diagnosed with an Autism Spectrum Disorder (ASD) according to estimates from CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network. ASDs are reported to occur in all racial, ethnic, and socioeconomic groups. ASDs are almost 5 times more common among boys (1 in 54) than among girls (1 in 252). Studies in Asia, Europe, and North America have identified individuals with an ASD with an average prevalence of about 1%. A recent study in South Korea reported a prevalence of 2.6%. About 1 in 6 children in the U.S. had a developmental disability in 2006-2008, ranging from mild disabilities such as speech and language impairments to serious developmental disabilities, such as intellectual disabilities, cerebral palsy, and autism. Studies have shown that among identical twins, if one child has an ASD, then the other will be affected about 36-95% of the time. In non-identical twins, if one child has an ASD, then the other is affected about 0-31% of the time. Parents who have a child with an ASD have a 2%–18% chance of having a second child who is also affected. ASDs tend to occur more often in people who have certain genetic or chromosomal conditions. About 10% of children with autism are also identified as having Down syndrome, fragile X syndrome, tuberous sclerosis, and other genetic and chromosomal disorders. The majority (62%) of children the ADDM Network identified as having ASDs did not have intellectual disability (intelligence quotient <=70). ASD commonly co-occurs with other developmental, psychiatric, neurologic, chromosomal, and genetic diagnoses. The co-occurrence of one or more non-ASD developmental diagnoses is 83%. The co-occurrence of one or more psychiatric diagnoses is 10%. Individuals with an ASD had average medical expenditures that exceeded those without an ASD by $4,110 to $6,200 per year. On average, medical expenditures for individuals with an ASD were 4.1 to 6.2 times greater than for those without an ASD. Differences in median expenditures ranged from $2,240 to $3,360 per year with median expenditures 8.4 to 9.5 times greater. In addition to medical costs, intensive behavioral interventions for children with ASDs cost $40,000 to $60,000 per child per year. Source: Centers for Disease Control and Prevention (CDC).