Autism May Cluster Among Highly Educated

Jan. 6 -- TUESDAY, Jan. 5 (HealthDay News) -- Highly educated, older parents are more likely to have a child diagnosed with autism, a new study finds.

Using data on about 2.5 million births in California in a five-year period, researchers identified 10 autism clusters, or geographical areas in which there was a higher than usual incidence of children diagnosed with the neurodevelopmental disability that's marked by impaired social and communication skills, and repetitive behaviors.

The rate of autism in the clusters was about twice that of the surrounding areas.

The parents' educational attainment was classified into one of four levels: less than 12 years of school, high school graduate, some college (13 to 15 years) or 16-plus years of school (college graduate or advanced degree).

Parents who lived in the areas where autism was more prevalent were more likely to be college graduates or hold advanced degrees than parents who lived outside the clusters.

"It confirms what we already knew, which is that highly educated parents are more likely to have children with autism," said the study's lead author, Karla Van Meter, an epidemiologist with the Sonoma County Department of Public Health who was a doctoral student in public health sciences at the University of California, Davis, when she conducted the research.

Mothers and fathers who were older when their child was born were also more likely to have autistic children, but parental age was not linked as strongly with autism as educational attainment, Van Meter said.

The study is in the Jan. 6 online issue of Autism Research.

The researchers identified 9,900 children born between 1996 and 2000 who were diagnosed with autism by age 6, according to the study. Data came from the California Department of Developmental Services, which coordinates services for children with autism.

Just why there appears to be a link between parents' educational level and autism is unclear, but theories abound.