Over the past several decades, the causes of autism spectrum disorder (ASD) have been widely discussed. Many people (experts included) believe that ASD results from environmental causes or habits of the mother in-utero. Even certain vaccinations fall into the realm of blame.
But the reality is that an ASD diagnosis can be a result of genetics, but the genetic signature that is responsible for the majority of ASD cases is still unknown. Sometimes it can be as simple as someone in your family having ASD, no matter how distanced they might be on the family tree, but not always.
So, if you’ve found yourself wondering ”is autism hereditary?” this blog is here to tell you that genetics play a key role. Read on for more about how genes impact the development of autism.
While ASD is something you’re born with, it’s actually considered a developmental disorder. It includes a broad range of conditions — hence the name autism spectrum disorder. Many of these conditions center on challenges with social interaction, speech, nonverbal communication, and repetitive behaviors.
Today, autism affects 1 in 54 children in America.
This disorder is broad, as mentioned, and includes a variety of subtypes of autism. Many of these subtype conditions are a result of genetics as well as some environmental factors.
Due to the fact that it’s a spectrum disorder, some people with autism may face more severe challenges, while others might face fewer challenges. Some people might have a clear set of strengths, while others might have less.
When it comes down to it, there is no ”cookie-cutter” mold for those with autism — it looks different from one person to the next. A child with autism might be incredibly gifted with learning and problem-solving skills. While another might have serious learning disabilities.
Some people can live independently with ASD, while others might need much greater support. Much of the time, gene mutation and expression as well as certain environmental factors determine the autism spectrum.
The exact cause of ASD is not always easy to pin down from one person to the next. There are a few factors at play that impact a child’s risk of developing autism. But at the top of this list is genetics, researchers are still looking for the exact genetic signature to fully say that autism is genetic, but they are getting closer every day.
In short, autism is hereditary. But there are other risk factors that can play into its development, such as biology and environmental factors. These causes merely factor into the cause of ASD — they are not the primary reason a person might develop autism.
Some of the most common risk factors for autism, in conjunction with genetics, include:
- A child born to older parents
- Serious infections during gestation
- Birth difficulties/complications
- Genetic disorders such as fragile X syndrome, tuberous sclerosis, and Down Syndrome
Not only this, but males are four times more likely to develop autism than females.
Research on how genes contribute to autism development reaches back to the 1970s. This means that experts and researchers alike are fully aware of the fact the ASD is a hereditary condition.
Originally, a team of researchers discovered that identical twins tend to share the condition of autism at birth — known as the autism twin study of 1977. Since this discovery, research studies on the genetic culprits behind ASD have grown in leaps and bounds.
As research grows, scientists discover new information about the genetic changes that can result in autism. The mutation of DNA is intricate and complicated, and as mentioned, differs from one person to the next.
Since the autism twin study, several twin studies have followed. All of the results show that autism is very likely hereditary between twins, with an 80 percent chance between identical twins.
It’s worth mentioning that many experts believe that genetic mutations are not the sole cause of autism. It’s believed that some environmental factors and maternal immune issues may also contribute.
While these causes are not ruled out completely, they most likely only influence or intensify certain autism traits. At the end of the day, it’s genetics that dictates autism development.
Now, you might be wondering, is there such a thing as an ASD gene? And the simple answer is, no, not necessarily. There is no singular type of gene that causes autism.
Autism tends to stem from mutations within a number of different genes. However, there are some conditions that relate to autism that stem from mutations in one single gene. These include Rett syndromes, Down Syndrome, and fragile X syndrome.
So, in short, there is no singular type of mutated gene in all people living with autism. Nor is there one type of gene that causes autism if it mutates.
At present, there are over 100 different types of genes and mutations linked with autism. Most of these mutations impact the communication between neurons as well as the expression of other genes.
What researchers do know is that mutation of the EN2 gene has a significant impact on the likelihood of developing autism. It’s this gene that impacts the development of the brain.
Can genetics explain why a greater number of males tend to inherit autism than females? In some cases, yes. Research shows that females with autism display a much greater amount of genetic mutations than their male counterparts.
Whereas in males, it appears to take less genetic mutation to develop this condition. Males also tend to inherit their autism from unaffected mothers who might carry the DNA and pass it down.
Basically, this shows us that females are a little more resistant to genetic mutations and therefore need a much greater genetic ”hit” to develop ASD.
So, is autism hereditary? Your family genetics can play a key role in whether your child develops ASD or not, but when you get the right testing done you can better prepare for diagnosis like ASD and other rare diseases. Knowledge is key to knowing what works best for you and your family.
If you’re interested in getting to know more about your DNA and any genetic predispositions you might have, then Sequencing is your go-to. We offer clinical-grade, safe and secure kits to test your DNA in the privacy of your own home. Sequencing’s Rare Disease Screening package includes an assessment for rare causes of autism, but it can’t detect a genetic cause in the majority of people diagnosed with autism.
It’s as simple as a mouth swab and you could learn a plethora of information about your health. Find out more about how it works, here.