Uncles, Aunts With Autism Might Increase Child's Likelihood Of Becoming Autistic, Says Study

Children who have an uncle or aunt who is autistic seems to have more than twice the risk of developing autism spectrum disorder themselves, reported a recent study.

Approximately 3 to 5 % of children with an aunt or uncle who have autism can be expected to develop the neurodevelopmental disorder themselves in comparison to just 1.5% of children overall, reported the U.S. government-funded study.

However, researchers portray this finding as a piece of assuring news for someone with an autistic sibling, who is thinking about having children.

Parents with one autistic child have a 20-50% chance that they will have another child who might also be diagnosed with autism spectrum disorder (ASD).

"On average, these results are a potential source of reassurance to siblings of individuals with autism, in terms of having their own children. It shows the risk is elevated, but not dramatically," the study’s co-author Dr. John Constantino, director of child and adolescent psychiatry at the Washington University School of Medicine in St. Louis told WebMD.

ASD is a complex neurodevelopmental disorder that starts early in childhood and affects a person’s communication, social skills, and learning.

The findings of the study revealed that there isn’t any statistical difference between the genetic risk from mothers who has an autistic sibling and fathers with a sibling who has this neurodevelopmental disorder.

They also revealed that while increased, the genetic risk of autism that comes from having an uncle or aunt with autism didn’t exceed what one would expect based on older studies associated with the role of genetics in ASD.

“People with siblings or parents with autism shouldn't let the results of this study influence their plans to have children. It's premature to apply the results of a single study to something as sensitive and complex as family planning," Kristen Lyall, an assistant professor with the Drexel University Autism Institute in Philadelphia told WebMD.

The findings also cast doubt on a theory of ASD that says that girls have a built-in resistance to the autism-related genes which explains why three times as many boys get diagnosed with ASD compared to girls.

If the female protective effect hypothesis is true, many women who carry such risk factors might remain unaffected but then pass those autism-related genes to their sons, said the researchers.