Older maternal and paternal age are jointly associated with having a child with autism, according to a recently published study led by researchers at The University of Texas Health Science Center at Houston (UTHealth).

The researchers compared 68 age- and sex-matched, case-control pairs from their research in Jamaica, where UTHealth has been studying autism in collaboration with The University of the West Indies, Mona Campus, Kingston, Jamaica.

"This should put to rest discrepancies in previous studies showing that just maternal age or just paternal age are linked to having a child with autism," said Mohammad Hossein Rahbar, Ph.D., principal investigator and professor of epidemiology and biostatistics at The University of Texas School of Public Health, part of UTHealth.

"Our results revealed that the age of the father and the mother are jointly associated with autism in their children," said Rahbar, who is also director of the Biostatistics, Epidemiology and Research Design (BERD) component of the Center for Clinical and Translational Sciences (CCTS) at UTHealth.

In the study, researchers found that mothers who had children with autism were on average 6.5 years older than women who did not have a child with autism. The corresponding age difference for fathers was 5.9 years.

In previous studies, Rahbar said that because of the statistical models used, it was hard to assess both maternal and fraternal age as joint risk factors, a problem called multicollinearity. He was able to use more complex statistical models to avoid the problem.

Autism Spectrum Disorders (ASDs) are complex, neurodevelopmental and behavioral disorders characterized by impairments in social interaction and communication and repetitive, sometimes obsessive, behaviors. According to the Centers for Disease Control and Prevention (CDC), a conservative estimate is that one in every 100 children has an ASD.

The research was published this month in the Journal of Autism and Developmental Disorders. Data for the study was collected at the UWI and utilized an existing database established by co-author Maureen Samms-Vaughan, M.D., Ph.D., professor of child health at UWI and principal investigator of the UWI subcontract. Funding for the research is provided by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the National Institutes of Health Fogarty International Center (NIH/FIC). Additional support came from the CCTS, which is mostly funded by the NIH National Center for Research Resource (NCRR) Centers for Clinical and Translational Sciences.

Co-authors from UTHealth are Katherine A. Loveland, Ph.D.; Eric Boerwinkle, Ph.D.; Deborah A. Pearson, PhD.; Jan Bressler, Ph.D.; Megan L. Grove-Gaona; Zhongxue Chen; Manouchehr Ardjomand-Hessabi; and Kari Bloom. Co-authors from UWI are Sydonnie Shakespeare-Pellington and Compton Beecher.