Health
Is Autism Genetic
Gene Mutations, Genetic Testing, And The Importance Of The Family History Of Autism Spectrum Disorder (ASD) For Effective Treatment And Diagnosis, in Improving the Lives of Individuals With ASD
Autism, a complex neurodevelopmental disorder, has always been a puzzling condition for scientists, but recent breakthroughs are finally shedding light on its genetic basis.
For a long time, the exact causes of autism remained a mystery, but now, thanks to advancements in research, we’re beginning to understand the significant role that genetics plays in autism.
The knowledge of the genetics behind autism helps us better understand the complex causes of this condition, leading to better ways to spot it early on, personalized treatment choices, and provides valuable insights for affected individuals and their families.
In this article, we’ll dive into the world of genes and autism, exploring how genetics plays a major role in Autism.
Autism Genetics background:
Researchers have gained insights into the genetic contribution to autism through various studies. One important line of evidence comes from twin studies conducted since 1977. These studies have consistently shown that autism has a strong heritable component.
When one identical twin has autism, there is approximately an 80 percent chance that the other twin will also have it. In fraternal twins, the concordance rate drops to around 40 percent, indicating a lower genetic influence.
Certain environmental influences, such as maternal immune responses during pregnancy or birth complications including preterm birth, low birth weight, and maternal diabetes or high blood pressure during pregnancy, have been suggested to interact with genetic factors, potentially increasing the likelihood of autism or influencing its characteristics.
Therefore, researchers believe that a complex interplay between genetic and environmental factors contributes to the risk of autism.
Is autism caused by a single gene mutation?
In most cases of autism, it is not caused by a single gene. While certain genetic syndromes can be associated with autism and result from mutations in a specific gene, such as Fragile X syndrome and Rett syndrome, these cases are relatively rare.
For the majority of individuals with autism, multiple genes and genetic variations contribute to the condition. Approximately 100 genes are found to be strongly associated with autism.
Researchers have identified a growing list of genes that are believed to be involved in its development. Some of the commonly associated genes include SHANK3, CHD8, NLGN3/NLGN4, FMR1, PTEN, TSC1/TSC2, NRXN1, and CNTNAP2. These genes are believed to play a significant role in the development of the disorder.
The genetic basis of autism is complex and involves the interaction of various genes, genetic factors, and environmental influences. Therefore, it is not accurate to say that a single gene is responsible for autism in most cases.
How do these genes contribute to autism?
These genes linked to autism spectrum disorder (ASD) are like the building blocks of brain development. They control important processes that shape how our brains grow and work.
Some of these genes help create the special cells in our brains(Neurons), while others build the connections between neurons (synapses) or the projections that transmit signals within neurons (dendrites).
You can think of it as a complex construction project. These genes are the architects and builders, making sure everything is in the right place and functioning properly.
So, when there are changes or mutations in these genes associated with ASD, it can disrupt the construction process of the brain.
This can lead to an excess of neurons or abnormal growth in certain parts of the brain’s outer layer called the cortex. These irregularities in the brain can specifically affect the frontal and temporal lobes of the brain, which are involved in emotions, social behavior, and language.
That’s why individuals with ASD often show differences in social interaction, communication, and thinking patterns.
How do people acquire mutations?
While the specific causes of ASD are still not fully understood, research has shown that both inherited (germline) and de novo (spontaneous) gene mutations can contribute to the risk of developing ASD.
Inherited gene mutations are passed down from parents to their children. These mutations can be present in the germline cells (sperm and egg) and affect the genetic material inherited by the child.
De novo mutations, on the other hand, occur spontaneously in an individual and are not inherited from parents. They arise as new mutations during the formation of egg or sperm cells or early in fetal development.
These mutations contribute to the genetic risk and can disrupt genes involved in neurodevelopment, potentially increasing the likelihood of developing autism.
Why does autism strike four times as many boys as girls?
The Centers for Disease Control reports that autism prevalence is four times higher for boys than girls.
A study led by University of Minnesota researcher Nicola Grissom shed light on this phenomenon. The research, published in Molecular Psychiatry, highlighted the existence of a “female protective effect” in autism spectrum disorders. While the exact reasons for this protective effect remain elusive, the study opens a door to understanding and one day better treating the disorder.
Grissom said; “Researchers have known about the ‘female protective effect’ in autism spectrum disorders for quite a while, but the reasons why girls might be protected while boys are vulnerable have remained mysterious.”
Overall, the study underscores the importance of further investigating the biological mechanisms underlying the sex differences in autism and their potential implications for diagnosis, treatment, and support for individuals on the autism spectrum.
Is there shared genetics between autism and other neurodevelopmental disorders?
Genetic studies have revealed overlapping genetic risk factors between autism and other neurodevelopmental disorders, such as:
- attention-deficit/hyperactivity disorder (ADHD)
- schizophrenia
- Intellectual disability
This shared genetic architecture suggests common underlying biological pathways and mechanisms. Understanding these shared genetics can potentially lead to the development of targeted interventions that benefit multiple disorders.
Is genetic testing available for ASD?
If your child receives a diagnosis of autism spectrum disorder (ASD), the doctor may recommend genetic testing. Genetic testing looks for causes of ASD but cannot be used to diagnose ASD. Some individuals with ASD have what is known as syndromic ASD, which means they have additional distinctive features or birth defects alongside ASD. Most people with syndromic ASD have a genetic cause for their ASD.
Genetic testing is more likely to find a genetic cause for ASD if
- Your child or another family member has syndromic ASD
- A family member has an ASD-related genetic change found through genetic testing
- Multiple family members have ASD.
The most common type of genetic test ordered for individuals with ASD is called chromosomal microarray (CMA). This test examines the chromosomes to detect any missing or extra parts that could contribute to ASD. CMA identifies a genetic cause in approximately 5% to 14% of individuals with ASD who undergo the test.
It is important to evaluate children with ASD for genetic disorders that can be associated with ASD. Fragile X syndrome, one of the most common causes of intellectual disability, is found in about 0.5% of individuals with ASD. Testing for Fragile X syndrome is recommended for all individuals with ASD.
Rett syndrome, which primarily affects females, is present in about 4% of females with ASD, warranting consideration for testing.
If CMA and genetic testing do not provide a definitive cause for ASD, whole exome sequencing may be recommended. This test examines the parts of DNA responsible for protein production and identifies genetic changes. Whole exome sequencing detects a cause in around 8% to 20% of individuals with ASD who undergo the test.
Even if you don’t have a family history of ASD, talk to your child’s doctor if you have concerns about your child’s development.
Why is it important to know if you have a family health history of autism spectrum disorder?
Knowing your family’s history with autism spectrum disorder (ASD) is super important for a few reasons.
- First, if ASD runs in your family, there’s a higher chance that you or your child could be affected. It’s like a heads-up that you might have a genetic predisposition to ASD.
- Second, understanding your family history helps you figure out the chances of having another child with ASD if you already have one. It’s good to know what you might be up against and be prepared for any potential challenges.
- When you’re planning a pregnancy or are already pregnant, sharing your family’s ASD history with your healthcare provider is crucial. They can keep an eye out for any red flags and provide the right support and guidance throughout your journey.
- By knowing your family’s ASD history, you can make informed decisions about genetic testing, prenatal care, and early interventions. Early interventions can make a world of difference in improving outcomes for individuals with ASD.
So, being aware of your family’s history empowers you to take proactive steps to support your child’s well-being and give them the best possible start in life.
Conclusion:
The role of genetics in autism has emerged as a crucial area of research, offering valuable insights into the underlying biology and potential therapeutic targets. While genetic factors are not the sole cause of autism, they contribute significantly to its etiology and have implications for diagnosis, treatment, and support.
Continued research into the genetics of autism holds the promise of improving our understanding of neurodevelopmental disorders and paving the way for more personalized and effective interventions, ultimately improving the lives of individuals on the autism spectrum and their families.
I appreciate your Attention. Your suggestions or feedback related to it are more than welcome in the comment section.
Join me on a healthier life journey. Check my article on things you shouldn’t be doing to your eyes if you love them. As a new creator on Medium, I need your support to continue delivering engaging content. Your contribution as a member or by sharing my work through this link makes a world of difference. Let’s inspire and connect through words together. Thank you for your support!
