When families receive an autism diagnosis, one of the first questions that often comes up is about genetics. These are completely understandable concerns, and we want to help you understand what current research tells us about autism and genetics.
While we know that genetics plays a significant role in autism, it’s not as simple as one gene or one parent being “responsible.”
Let’s explore what we know about the genetic factors involved in autism and how they might influence families.
Which Parent Carries the Autism Gene: Mother or Father?
Both mothers and fathers can carry genes associated with autism. Since every child receives genetic material from both parents, either parent can potentially pass along genes that increase the likelihood of autism.
However, if we’re looking at which parent’s genetics might have a slightly stronger influence, recent research suggests something interesting. Some studies indicate that the autism paternal gene, i.e. certain genetic variations from fathers might be passed on more frequently, as siblings with autism often share more genetic material from their father’s side.
This doesn’t mean fathers are “to blame” for autism, nor does it mean mothers don’t contribute genetically. Autism genetics are incredibly complex, involving multiple genes and factors that we’re still learning about.
Understanding Autism and Its Associated Genes
Autism Spectrum Disorder isn’t caused by a single genetic change. Instead, multiple genes can increase a person’s likelihood of being on the spectrum.
Researchers have identified several important genes, including SHANK3, ADNP, and CHD8, among others. Some gene variations, like certain MTHFR gene mutations, have also been associated with autism, particularly when inherited from the mother.
You might wonder: “Is autism caused by a gene mutation?” The answer is that mutations in certain genes can affect brain development in ways that align with autism characteristics, and autism heritability is a factor in about 40%-80% of the cases.
Paternal Genetic Factors
One area that has received significant research attention is the relationship between a father’s age and autism risk. As men age, there’s a higher chance of sperm with genetic mutations, including some that might be linked to autism.
Research has found that fathers over 50 years old have about a 66% higher chance of having a child on the autism spectrum compared to fathers under 30.
However, it’s crucial to understand that this is still a relatively small overall risk, and many older fathers have children who are not on the spectrum.
Maternal Genetic Contributions
Mothers also contribute important genetic factors that can influence autism risk. For example, certain variations in the MTHFR gene have been associated with autism when present in the mother’s genetic makeup. Additionally, maternal health during pregnancy, including factors like prenatal vitamins and overall wellness, can interact with genetic factors.
It’s essential to remember that both parents contribute equally to their child’s genetic makeup, and autism risk factors can come from either side of the family.
The Interaction Between Genetics and Environment
One of the most important questions families ask is: “Is autism genetic or environmental?” The answer is that it’s likely both, working together in complex ways.
While genetics provides the foundation, environmental factors during pregnancy and early development can also play a role. These might include things like prenatal infections, certain medications, or other environmental exposures.
The interplay between specific genetic variations (like genes ASH1L, ARID1B, CHD2, CHD8, DYRK1A, POGZ, SYNGAP1, and SHANK3) and environmental factors helps shape each person’s unique presentation on the autism spectrum.
Understanding Co-Occurring Conditions
When discussing genetics and autism, it’s important to recognize that many individuals on the spectrum also experience other conditions. These can range greatly. For instance, they might include:
- Gastrointestinal issues
- Sleep challenges
- Anxiety or ADHD
- Epilepsy
Understanding these co-occurring conditions is important because they can significantly impact quality of life and may require additional support. The good news is that when these conditions are recognized and addressed alongside autism-specific support, families often see significant improvements in their child’s overall well-being and happiness.
Recognizing signs early and seeking appropriate interventions can make a tremendous difference for children and their families.
Early Detection, Genetic Testing, and Hope for the Future
Many parents often wonder: “If I have autism, will my child have it?” or “If my husband has autism, will my child have it too?”. Those questions are completely natural.
Here’s something important to know: while genetics do play a role, they’re not a crystal ball. Two parents on the autism spectrum can absolutely have a neurotypical child, and parents with no apparent autism traits can have a child on the spectrum.
Today, genetic testing can provide some insights into potential autism-related genes, though it can’t definitively predict whether a child will be on the spectrum. What these tests can do is help families understand potential risks and prepare for early intervention if needed.
It’s also important to note that new breakthroughs in researching autism spectrum are still happening and showing how little we know about ASD. The newest Princeton study from July 2025 analysed 230 symptoms in over 5,000 children and came to some amazing findings. The expert team, led by Dr. Olga Troyanskaya, identified four distinctive autism subtypes, different not only in their symptoms, but their causes as well.
What’s more, the scientific data indicates that certain genetic mutations which act as triggers for autism may appear well after birth, depending on the autism subtype.
The Power of Early Support
Thanks to advances in genetic testing, families can now gain early insights into autism-related markers, opening the door to earlier awareness and support.
Starting ABA interventions as early as two years old can make a meaningful difference in a child’s development. Early diagnosis helps us tap into the brain’s natural adaptability, giving children the tools they need to grow with confidence.
We’ve seen firsthand how starting therapy early can have a profound impact on their happiness, communication, and overall well-being.
According to the latest autism statistics, the average age of diagnosis is still around 4 years old. Interestingly, the group showing the fastest increase in diagnoses today is young adults.
Parents, caregivers, and educators play a vital role in recognizing early signs and ensuring children get the support they need as soon as possible.
Looking at the Bigger Picture
Does autism come from the mother or the father? As a matter of fact, autism can come from both. The gender of the parent is not the determining factor in whether a child is born on the spectrum or not. Also, while understanding autism genetics helps us see the bigger picture, it doesn’t define if a child is born on the spectrum or not.
Although studies have highlighted a slightly elevated risk from the paternal side, especially with increasing age, it’s essential to remember that no single gene determines autism. As a matter of fact, the deciding genetic interaction can occur even in the years after the birth, as explained in the above-mentioned Princeton ASD study.
Finally, it’s important to remember that autism’s origins are a blend of intricate genetic and environmental factors, and they also may play a role during prenatal development in this intricate genetic dance.
FAQs
Can neurotypical parents have an autistic child?
Yes, they can. Even if parents don’t display any autistic traits or have a known family history of autism, they can have a child who is on the spectrum. The presence of autism can be influenced by spontaneous genetic mutations, but also by environmental factors.
How does autism get passed down?
Autism can be passed down through a combination of inherited genes and spontaneous genetic mutations. While inherited genes come directly from the parents, spontaneous mutations occur randomly and aren’t inherited from either parent. These mutations can influence the likelihood of autism in a child.
What are the 3 main causes of autism?
Autism’s etiology is multifaceted, but three primary contributors are:
- Genetic predisposition: Apart from the commonly discussed genes, there are other genetic markers and chromosomal abnormalities that can be linked to autism.
- Environmental exposures: Beyond prenatal exposures, early childhood exposures to certain chemicals or a lack of essential nutrients can also play a role.
- Brain connectivity and structure: Some research suggests that individuals with autism might have variations in certain areas of the brain, affecting connectivity and neural pathways, which can influence autistic traits.