Reported by the Centers for Disease Control and Prevention, Dec. 18, 2009

It is estimated that an average of 1 in 110 children in the United States have an Autism Spectrum Disorder. 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.

If 4 million children are born in the United States every year, approximately 36,500 children will eventually be diagnosed with an ASD. Assuming the prevalence rate has been constant over the past two decades, we can estimate that about 730,000 individuals between the ages of 0 to 21 have an ASD.

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.

Risk Factors and Characteristics
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.

On average, 41% of the children who had an ASD also had an intellectual disability.

About 40% of children with an ASD do not talk at all. Another 25%–30% of children with autism have some words at 12 to 18 months of age and then lose them. Others may speak, but not until later in childhood.

Diagnosis
The median age of earliest ASD diagnosis is between 4.5 and 5.5 years, but for 51%–91% of children with an ASD, developmental concerns had been recorded before three years of age.

Studies have shown that about one third of parents of children with an ASD noticed a problem before their child’s first birthday, and 80% saw problems by 24 months.

Economic Costs
Recent studies have estimated that the lifetime cost to care for an individual with an ASD is $3.2 million.

Individuals with an ASD had average medical expenditures that exceeded those without an ASD by $4,110–$6,200 per year. On average, medical expenditures for individuals with an ASD were 4.1–6.2 times greater than for those without an ASD. Differences in median expenditures ranged from $2,240 to $3,360 per year with median expenditures 8.4–9.5 times greater.