A new research has found that household income level has no association with either intellectual disability (ID) or autism spectrum disorders (ASD).
The research conducted by the University of Utah in collaboration with the Utah Department of Health (UDOH) shows that the presence or absence of ID and ASD varies with risk factors such as gender, parental age, maternal ethnicity and the level of maternal education.
ASDs are a group of childhood neurodevelopmental disorders characterized by problems with social interaction, communication, and restricted and unusual behaviors, varying widely in severity and may be accompanied with or without ID.
"ASDs represent a diverse group of conditions that may have different causes, and children with ASDs, either with or without ID, represent opposite ends of the autism spectrum," Newswise quoted Judith Pinborough-Zimmerman, and first author of the study as saying.
"By identifying risk factors associated with ASDs, we may be able to gain a better understanding of the underlying causes of autism," she stated.
Pinborough-Zimmerman and her colleagues identified children with ASD and/or ID in a three-county area surrounding Salt Lake City through the Utah Registry of Autism and Developmental Disabilities (URADD), a multiple-source, population-based surveillance program.
They evaluated a variety of demographic factors and found that children with ASD but not ID were significantly more likely to be male and to have mothers of white, non-Hispanic ethnicity, whereas children with both ASD and ID were also more likely to be male, but were more likely to have mothers older than 34 years of age.
On the other hand children who had ID but not ASD were significantly more likely to have fathers older than 34 years of age and significantly less likely to have mothers with more than 13 years of education.
To investigate the link between socio-economic factors and autism, Pinborough-Zimmerman and her colleagues examined how various measures of income changed over an eight-year period in families with a child with ASD and/or ID, as compared with the general population and found no clear association between markers of income and the risk for ASD and/or ID.
The study has been published in the 15th September 2011 issue of Autism Research.