Is autism genetic? This is a major question of many people who are concerned about the possibility of the occurrence of this disorder in themselves or their loved ones.
Autism research suggests several genetic factors associated with birth defects that can lead to autism. Other than the genetic factors, several environmental risk factors and nongenetic factors can be responsible for this disorder in autistic children.
This article covers genetic factors behind ASD, the autism risk factors, and how genetic mutations affect the child with an increased risk of autism spectrum disorders.
Is Autism Genetic?
Is autism genetic? The short answer is that we don’t know. Autism is a complex disorder that may be caused by a combination of genetic and environmental factors. Researchers have identified a number of genes that may be associated with autism.
However, it’s unclear how these genes interact with each other and the environment to cause autism. While there is no definitive answer to whether autism is genetic, research suggests that it likely has a strong genetic component.
Studies suggest that autism is a strongly genetic disorder.
Even though some studies suggest that autism is a strongly genetic disorder, recent studies indicate that the development of autism results from genetic, nongenetic, and environmental factors that are associated with autism.
Even though there is not a single gene that causes autistic spectrum disorders in children, there are hundreds of gene variations that affect brain development which results in the increased risk of autism. These factors can indicate the possibilities of autism genetic.
Autism spectrum disorder (ASD) is one of the most prevailing neurodevelopmental disorders that can affect an estimated 1.7% of children. ASD is highly genetically heterogeneous which can occur both due to the inherited genes and de novo genetic variations.
Genetic risk factors of autism:
Research suggests that autism is hereditary and runs in families. Although studies show that if a family history of a child has autism genetics in their parents – either father or mother- and even the father or mother carries a single gene or multiple genes of autism, it can possibly cause autism in the child, even if the parents do not have autism.
In the case of de novo genetic variations, genetic changes due to spontaneous mutations affect the embryo or the sperm and egg that create an embryo with the combination of two. These genetic influences do not specifically cause autism but they increase the risk factors of the development of autism.
Environmental risk factors of autism:
Research suggests that environmental influences can also affect the autism risk factors in people with a genetic predisposition to autism spectrum disorders.
An environmental risk factor results in an increased risk of autism in the child for people with pregnancy and birth complications. Whereas, prenatal vitamins during pregnancy, before conception, and after conception can decrease environmental risk factors of autism.
Link of Fragile X syndrome with autism:
Studies suggest that fragile x syndrome is the chief genetic cause of autism or autism spectrum disorders in children. It is also identified as one of the most common genetic factors and the cause identified for intellectual disability in children.
The diagnostic and statistical manual of mental disorders includes Asperger syndrome, pervasive developmental disorders (PDD), and even fragile x syndrome with autism spectrum disorders.
Research suggests that 1 in 3 people who are having this syndrome will have autism too. Even those people with this syndrome who don’t have autism, share certain autistic traits like eye contact avoidance and difficulty in public interactions, etc.
In short, genetic risk factors and environmental risk factors can both contribute to the development of autism in children.
Even the development of these rare mutations doesn’t necessarily mean that the child will develop autism.
Is autism from the mother or father?
Previously, researchers suggested that women are more prone to genetic risk factors of autism in their children as they have fewer autistic symptoms. Furthermore, they also thought that women have the same genetically engineered risk factors in them as in men, they tend to contribute more to the genetic risk factors in autistic children, being autism genetic.
But recent studies of inherited genes implicated that genetic mutations may get inherited in the children from their fathers.
During the research, the team found that only half of the structural variants of mothers are passed on to their autistic children, which suggests that the variants of the inherited genes from mothers did not have an association with autism.
On the other hand, fathers surprisingly pass on more than 50% of their variants to autistic children, which makes them the major contributor of autism in children.
Furthermore, recent research during the study of noncoding DNA reveals that the alterations in regions during brain development in regions involved in the regulation of gene activity may also become the leading cause of autism. And these gene variations are inherited from the father.
In short, studies mostly put fathers as the leading contributor of genetic factors that cause autism spectrum disorders in children.
All of this research can give you a brief idea of autism genetic.
Does ASD run in families?
Autism spectrum disorders have a high tendency to the genetic influence of autism to run in families. The children are at a higher ASD risk of developing autism spectrum disorders if their ancestors have gene changes associated with autism.
Although autism spectrum disorders have the tendency to run in families, the pattern of its inheritance is unknown.
Twin and family studies:
These studies suggest a strong indication that some people with autism already have a genetic predisposition to the disorder. According to the identical twin studies, if one of the two identical twins has this disorder, there is up to a 90% chance that the other twin will be an affected child.
In a study conducted by the researchers about autism genetic, they took a sample of 78 twin pairs, and 64 pairs out of these had autism in both identical twins.
What genes cause autism?
Considering autism genetic, the chances of autism spectrum disorders in children are increased if the parents are the silent carriers of the gene that causes autism.
It is a gene mutation that causes autism in the offspring. These mutations are of two types, namely mutations in inherited genes and de novo genes (not inherited genes).
According to Joseph Gleeson, MD, professor of neurosciences and pediatrics, University of California, the common cause of autism in children is the recessive (from both copies of the gene) genetic mutations in the gene ACTL6B. The mutations in this gene also lead to epilepsy and intellectual disability.
Who is at high risk for autism?
There are some factors that decide who is at the higher risk factors of autism:
1) Age of Parents:
Children who are born to dads older than 50 years have a higher chance of developing autism. The reason behind this is that the genetic mutations in sperms increase with age. Likewise, women who give birth after the age of 40, increase the chances of birth complications and the development of autism in the offspring.
2) Exposure to chemicals
Certain chemicals when exposed to the babies before birth increase the chances of autism in the children. The babies exposed to chemicals like pesticides and harmful chemicals found in plastic results in increased ASD risk in children.
3) Males vs Females:
If you are a male, you have a higher chance of developing autism. Recent research suggests that males are five times more prone to autism than females.
4) Exposure to pollution:
If a pregnant mother is more exposed to pollution, the offspring will be at a higher risk of developing autism.
Is autism genetic or hereditary?
Autism is caused by both genetic factors, nongenetic factors, and environmental risk factors. Research estimates that autism is autism comes under 40-80% chances of being heritable.
Other than that, research also suggests genes involved in the development of autism, i.e. genes contribute to the potential of autism in people.
Although this is not in control of the parents of autistic individuals, the rare de novo mutations were studied comparing the autistic individuals and unaffected family members, which showed that spontaneous mutations that arise after conception also contribute to the development of autistic traits in individuals even if the parents don’t carry the hereditary genes of autism.
What increases the risk for autism?
There are many genetic factors, nongenetic factors, and potential environmental factors that increase the risk of autism in individuals.
Some of the common factors are listed above which are considered some major factors that contribute to the development of autism in individuals.
Concluding, all the information provided above is meant to help the reader in analysing the possible and explanatory answers to the question ‘Is autism genetic?’