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What Causes Autism in Children?

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Harmony Care Finder Editorial · Published 2026-06-16 ·Updated 2026-07-01 · 7 min read
TL;DR — Quick Answer

Autism is caused by a combination of genetic and environmental factors — there is no single cause, and it is not caused by vaccines, parenting style, or anything a parent did or didn't do during pregnancy. Genetic factors account for roughly 80% of autism risk, with hundreds of genes implicated. Environmental factors like advanced parental age and certain prenatal exposures appear to modestly increase risk in genetically susceptible individuals.

What Causes Autism in Children? This is one of the first questions parents ask after a diagnosis. What the research shows is that autism does not have a single identified cause. It comes from a mix of genetic factors and, in some cases, prenatal environmental exposures. One thing the research is clear on: vaccines are not a cause. The study that claimed a link was retracted for fraud in 2010. Many large population studies since have found no relationship between vaccines and autism. What This Te

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Harmony Care Finder Editorial

The Harmony Care Finder Clinical Team is a group of Board Certified Behavior Analysts dedicated to helping families navigate the ABA therapy journey with evidence-based guidance and compassionate support.

Clinically Reviewed. All clinical content on Harmony Care Finder is reviewed by a licensed Board Certified Behavior Analyst under contract with our editorial team, evaluated against BACB practice guidelines and current peer-reviewed literature prior to publication.

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