Who Carries the Autism Gene: Mother, Father, or Both?

Autism spectrum disorder (ASD) is a complex developmental condition that affects social communication, behavior, and learning. One of the most common questions families, caregivers, and individuals ask is: Is autism genetic? 



Understanding the role of genetics alongside environmental factors is crucial for grasping what influences autism development. This comprehensive, friendly guide explores the science behind autism’s origins, answering key questions such as which parent carries autism genes, the percentages linked to genetics versus environment, and what environmental causes contribute to autism.

What Does “Is Autism Genetic?” Really Mean?

When we ask if autism is genetic, we want to understand whether autism traits are inherited through DNA. Scientific evidence shows that genetics plays a major role in autism—a strong hereditary component influences susceptibility. However, autism is not caused by a single gene but by a complicated interplay of multiple genes and sometimes spontaneous genetic mutations.

Studies estimate that around 80 to 90 percent of autism risk is attributed to genetic factors. These include inherited gene variations passed down by parents as well as new mutations that arise in the individual. Yet genetic risk alone does not fully explain autism, pointing to additional influences from environmental causes.

Exploring the Genetic Landscape of Autism

Polygenic Basis: Multiple Genes at Play

Autism is a polygenic condition, meaning many different genes contribute to risk. Over 200 to 1,000 genes have been identified as impacting autism susceptibility. These genes affect brain development, neuronal function, and synaptic communication.

De Novo Mutations: New Genetic Variations

Some cases of autism result from de novo mutations—new genetic alterations that occur spontaneously in the sperm or egg cells and are not inherited from parents. These are important, especially in families without a history of autism.

Genetic Heritability: How Likely Is Autism to Run in Families?

• Studies show that if one child in a family has autism, the chance of another child also having autism is significantly higher than in the general population.
  
  
• Twin studies estimate autism's heritability to be approximately 80 to 90%, indicating genetics largely influence autism’s development.

Who Carries the Autism Gene: Mother or Father?

A common question is whether autism genes are inherited more from the mother or the father. Research indicates:

• There isn’t one specific “autism gene” inherited solely from one parent. Instead, both mother and father contribute genetic variations linked to autism.
  
  
• Some studies suggest siblings with autism may share more genetic material from their father, pointing to a stronger paternal genetic influence for certain autism cases.
  
  
• Maternal factors also play a critical role—not only genetically but environmentally during pregnancy—such as maternal infections or exposure to toxins.
  
  

In short, both parents can pass on genetic markers associated with autism, and environmental factors related to the mother during pregnancy may interact with these genes.

Is Autism Genetic or Environmental?

Autism results from an interaction between genetic predispositions and environmental influences. While genetic factors account for the majority of autism risk, environmental factors may trigger or increase the likelihood of developing autism when combined with certain genetic vulnerabilities.



What Percentage of Autism Is Genetic?

Based on large-scale studies across countries:

• Approximately 80% of autism risk is attributed to inherited genetic factors.
  
  
• The remaining 20% or less comes from environmental exposures and other non-genetic influences.
  
  
• These genetic effects include inherited genes, de novo mutations, and gene-environment interplay.
  
  

This does not mean the environment is unimportant, but genetics provides the foundation for risk.

Environmental Causes of Autism

While genetics contributes most of the risk, environmental causes are recognized as important modifiers that can raise or lower the chances of developing autism, especially during prenatal and early life stages. Key environmental factors associated with autism include:

• Advanced parental age at conception (both maternal and paternal age)
  
  
• Prenatal exposure to certain chemicals or pollutants, such as air pollution or pesticides
  
  
• Maternal health conditions, including infections, diabetes, obesity, or immune disorders during pregnancy
  
  
• Complications during birth, such as preterm birth, low birth weight, or oxygen deprivation
  
  
• Use of certain medications during pregnancy (e.g., valproic acid)
  
  

It is important to emphasize that vaccines are not linked to autism, as supported by extensive scientific research.

Environmental factors generally increase autism risk in combination with genetic susceptibility, rather than acting as sole causes.

How Divine Steps ABA Supports Families Navigating Autism Genetics and Environment

At Divine Steps ABA, we understand the multifaceted nature of autism and the importance of personalized, evidence-based care. Here is how we stand apart:

• Individualized ABA Therapy: Tailored plans recognize each client’s unique genetic background, sensory needs, and environmental influences, addressing core behaviors and skills.
  
  
• Collaborative Family Engagement: We provide resources and counseling to help families understand autism’s complex causes, empowering informed decisions.
  
  
• Multistate Accessibility: Serving Maryland, Virginia, and North Carolina, we deliver in-home and clinic-based services flexible to families’ lifestyles.
  
  
• Holistic Focus: In addition to behavior support, we help clients build communication, social skills, and emotional regulation influenced by both biology and environment.
  
  
• Ongoing Education: We keep families updated on the latest autism research regarding genetics and environmental studies to support holistic care.
  
  

Divine Steps ABA is your partner in unraveling autism’s complexities, providing therapeutic strategies that promote growth, independence, and well-being.

Conclusion: Take the Next Step Toward Understanding and Support

Understanding is autism genetic? is only part of the journey. Autism’s roots in genetics are intertwined with environmental factors, highlighting the need for comprehensive support.

If you or a loved one is navigating autism, turn to Divine Steps ABA for specialized, compassionate care in Maryland, Virginia, or North Carolina. Our expert teams combine science with personalized therapy to empower every client’s unique strengths.

Connect with Divine Steps ABA today and embark on a path of discovery, growth, and confidence that honors your family’s story. Schedule a visit and step forward with tailored support for a brighter tomorrow.

Frequently Asked Questions (FAQs)

Sources:

1. https://medschool.ucla.edu/news-article/is-autism-genetic
2. https://my.clevelandclinic.org/health/articles/autism
3. https://www.bbc.com/future/article/20250415-the-genetic-mystery-of-why-some-people-develop-autism
4. https://en.wikipedia.org/wiki/Heritability_of_autism
5. https://news.ki.se/what-do-we-know-about-genes-and-environmental-factors-in-autism
6. https://www.nichd.nih.gov/newsroom/news/080119-autism
7. https://molecularautism.biomedcentral.com/articles/10.1186/s13229-017-0121-4
8. https://www.autism.org.uk/advice-and-guidance/what-is-autism/the-causes-of-autism
9. https://www.autismparentingmagazine.com/which-parent-carries-autism-gene/
10. https://sparkforautism.org/discover_article/environment-autism/
11. https://www.uclahealth.org/news/release/new-genetic-clues-uncovered-largest-study-families-with
12. https://www.niehs.nih.gov/health/topics/conditions/autism
13. https://www.autismawareness.com.au/navigating-autism/causes-of-autism
14. https://www.psychiatrist.com/news/siblings-with-autism-share-more-of-fathers-dna-not-mothers/
15. https://med.stanford.edu/news/all-news/2011/07/non-genetic-factors-play-surprisingly-large-role-in-determining-autism-says-study-by-group.html
16. https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-024-03617-3
17. https://www.mayoclinic.org/diseases-conditions/autism-spectrum-disorder/symptoms-causes/syc-20352928