Is Autism Genetic?

With autism rates increasing in recent years, many prospective parents are searching for answers on their kids being diagnosed with autism and what they can do about it. One in 54 children had been diagnosed with autism by age 8 in 2016, compared to 1 in 150 in 2000. However, this does not necessarily mean that the number of babies born with autism is increasing. Other factors such as improved diagnosis and awareness, as well as changes in diagnostic criteria may be contributing to the increase in the prevalence of autism. It is understandable that parents of children with autism may worry about their child’s future, social isolation, and the impact on family dynamics. Parents may also feel overwhelmed, guilty, confused, angry, or depressed in response to their child’s diagnosis or symptoms. Parents of children with autism spectrum disorder (ASD) often experience feelings of guilt related to their child’s condition. This guilt can be caused by a variety of factors, such as feeling responsible for their child’s diagnosis, feeling like they are not doing enough for their child, or feeling like they have somehow caused their child’s condition.

What Causes Autism?

Answering this question is not easy because, despite all of the research that has been done, there are no definitive answers to the cause of autism. There is evidence that autism is caused by a number of genetic and non-genetic factors, including heredity and the environment. But it is important to remember that autism is a complex disorder resulting from the influence of many factors.

Is Autism Genetic?

Probably. A recent study that looked at autism in 5 countries found that 80% of autism risk can be traced to inherited genes. While there is no specific “autism gene” there are several conditions associated with autism that stem from mutations in a single gene, including fragile X and Rett syndromes. But less than 1% of non-syndromic cases of autism stem from mutations in a single gene. No one gene has been discovered that causes autism every time it is mutated. Still, the list of genes implicated in autism is growing. Researchers have tallied about 100 genes in the last few years that they now consider to be strongly linked to autism.

Is Autism a Genetic Disorder?

Possibly. While autism is classified as a neurodevelopmental disorder, there are many genes in which rare mutations are associated with autism—often with other signs and symptoms. Researchers are still working to identify all of the genes associated with autism, but they do know that some genetic mutations can increase the risk of developing autism.

Is There a Genetic Test for Autism?

There are a few. The most commonly ordered test for people with autism is a chromosomal microarray (CMA). This test looks at chromosomes to see if there are extra or missing parts that could cause autism. CMA has found a genetic cause in 5% to 14% of the people with autism who have taken the test. It is strongly recommended that anyone with an autism diagnosis get genetic testing. Unfortunately, less than half of people with autism do.

For parents who want to check their unborn child’s risk of having autism there is prenatal genetic testing (PGT) for autism which is currently available via clinical genetic services. This test can prepare parents for the birth of an affected infant, and allow them to arrange for early interventions.

Is Autism Environmental?

It can be. These following factors alone are unlikely to cause autism, but they do appear to increase a child’s risk for developing autism when combined with other genetic factors:

  • Advanced parental age at time of conception
  • Prenatal exposure to air pollution or certain pesticides
  • Maternal obesity, diabetes, or immune system disorders
  • Extreme prematurity or very low birth weight
  • Any birth difficulty leading to periods of oxygen deprivation to the baby’s brain

Is Autism Hereditary?

It can be. If someone in your family has autism you may be more likely to have a child with autism. The disorder can look very different from person to person, so taking a careful family health history can be important for early diagnosis. If you have a family member with autism, you may want to consider talking to your doctor about getting screened for the genetic mutations that could put you or a family member at higher risk.

It is also interesting to note that a study conducted in 2020 examined the role of familial relationships in explaining similarities in behaviors across family members. The researchers saw that parents of autistic children displayed some of the traits seen in their children in a much more muted manner. This means that traits in children with autism may take after their parents’ subtle autism-like behaviors.

Other Factors That May Lead to Autism

Children in families with a history of other mental conditions like ADHD, schizophrenia, and bipolar disorder are at a higher risk for developing autism. Also, male children are at a much greater risk of developing autism than girls. The answer may lie in specific biological shielding mechanisms that operate in girls but not boys; even when both sexes have the same genetic defects associated with the disorder.

One Factor That Definitely Does Not Lead to Autism

A rumor that has been prevalent for years is that vaccines cause autism. This is absolutely untrue, yet these unfounded claims have lingered on the internet and in certain communities for far too long. You can read more about this misconception on the Centers for Disease Control and Prevention’s Vaccine Safety page.

Going from Questions to Answers

While understanding the root cause of autism is important, what’s equally important is understanding the many things that can be done to help children, adolescents, and adults with this neurodevelopmental disorder to thrive. If you think that you or a loved one has autism it is critical to learn as much as you can as soon as you can. LifeStance has the information, providers and resources you need to deal with autism.

Authored By 

LifeStance Health
LifeStance Health

LifeStance is a mental healthcare company focused on providing evidence-based, medically driven treatment services for children, adolescents, and adults.