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Elena Donovan Mauer
Contributing Writer

New Autism Risk Factors, Dad’s Age and Preterm or Post-term Delivery

PUBLISHED ON 04/04/2012

It’s Autism Awareness Month, and there’s a lot that’s unknown about autism spectrum disorders (ASDs), so we’ve been hearing quite a bit about the latest studies on the subject. Here’s the latest scoop on some things that could increase a child’s risk of having an ASD or having more severe ASD symptoms.

Dad’s Age

Researchers have been unable to pinpoint genetic causes of ASD, but they do believe they’re a factor. One new study suggests that the answer could be linked to the child’s father’s age. Several teams, including researchers at the Harvard/MIT Broad Institute, Yale University and the University of Washington worked together to analyze the DNA of 549 families with at least one family member with autism. They found that certain genetic material could become mutated as they’re passed along to a child — about 14 percent of the people with autism has suspected mutations, which is about five times the normal rate. They found that the mutations can harm certain pathways in the brain, causing ASD symptoms. They also found that the number of those mutations increased with the father’s age.

Being born Preterm or Post-term

Previous studies have suggested that preemies have higher rates of autism, but a new study from Michigan State University looks at post-term babies too. The study, which was published in the Journal of Autism and Development Disorders looked at data on nearly 4,200 mothers who had autistic children ages four through 21. The moms filled out questionnaires on their children’s autism symptoms, and the researchers found that very preterm (born before 34 weeks gestation), preterm (34 to 37 weeks) and post-term (born after 42 weeks) autistic children had significantly higher screening scores for autism spectrum disorder than autistic children born full term (between 37 and 42) weeks. In other words, their symptoms were more severe if they were born before or after the full-term range.

“We think about autism being caused by a combination of genetic and environmental factors,” said researcher Tammy Movsas in a press release. “With preterm and post-term babies, there is something underlying that is altering the genetic expression of autism.”

More research needs to be done on both fronts, but we're hoping these studies help scientists hone in on the true causes of autism.

PHOTO: Tom Grill / Getty Images