• Understanding Autism from the Inside

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Does Autism Run in Families;A Genetic Link


Autism is a neurobiological disorder in which the brain develops different than those of children and adults without autism. Autistic individuals have brains that are wired “differently.” These differences are clearly seen to run in families.

A Study of Siblings of Autistic Children

According to a study of the siblings of autistic children published on August 15, 2011, autism does run in families. The prevalence or autism in siblings in the studies makes the conclusion clear. The incidence of families with an autistic child having another autistic child is 19%; however, that percentage went up in families who already had more than one autistic child. In this case, the incidence of the family having another autistic child is 32%. It appears that there is a much lower chance of a female sibling having autism (only 9%) according to the study despite the thoughts that girls may remain under-diagnosed.

What is My Family’s Risk?

“It’s important to recognize that these are estimates that are averaged across all of the families. So, for some families, the risk will be greater than 18.7 percent, and for other families it would be less than 18.7 percent,” said Sally Ozonoff, Ph.D., professor of psychiatry and behavioral sciences at the MIND Institute and the study’s lead author. “At the present time, unfortunately, we do not know how to estimate an individual family’s actual risk.”

Children of Autistic Parents

It is thought that autism is caused by both genetic and environmental factors together. However, with recent studies there seems to be a larger genetic fact than initially attributed. It is not uncommon for a parent with Autism, or Asperger’s Syndrome to have one or more autistic children. Many have reported multiple children on the autism spectrum suggesting a very strong genetic basis. Looking at family members often strengths these findings. Many times there are one or more relatives that have autism, or are reported to have “differences,” or trouble with social situations—showing autistic-like traits.

Is there An Autistic Gene?

Although research still continues, scientists have not been able to track down on specific autistic gene. It is thought that there are many genes that are associated with autism spectrum disorders. Scientific studies suggest that genetic mutations occur between generations, either genes being duplicated, or eliminated is a contributing factor.

According to scientific research, and incidences of autism observed within families, autism has an undeniable genetic factor. Families who have one or more parents with an autism spectrum disorder, and families who have one or more children diagnosed with autism are have a higher incidence of having another autistic child than the general population. Incidences of reoccurrence range from 19-32%, a statistic that many have bearings on family planning.


Jeannie Davide-Rivera

Jeannie is an award-winning author, the Answers.com Autism Category Expert, contributes to Autism Parenting Magazine, and the Thinking Person's Guide to Autism. She lives in New York with her husband and four sons, on the autism spectrum.