Due to its lower prevalence in females, autism was always thought to have a maternal inheritance component. However, research also suggests that the rarer variants associated with autism are mostly inherited from the father.
Although the exact cause of autism is still unknown, there is evidence to suggest that genetics play a significant role. Since autism is less prevalent in females, autism was always thought to be passed down from the mother. However, research suggests that autism genes are usually inherited from the father.
But surprisingly, fathers did pass on substantially more than 50% of their variants. This suggests that autistic children might have inherited risk variants in regulatory regions from their fathers but not their mothers, the researchers report today in Science.
Having a family health history of ASD makes you more likely to have a child with ASD, or to have ASD yourself. If you have a child with ASD, you are more likely to have another child with ASD, especially if you have a daughter with ASD or more than one child with ASD.
Inheritance. ASD has a tendency to run in families, but the inheritance pattern is usually unknown. People with gene changes associated with ASD generally inherit an increased risk of developing the condition, rather than the condition itself.
There is not just one cause of ASD. There are many different factors that have been identified that may make a child more likely to have ASD, including environmental, biologic, and genetic factors.
According to the CDC, the prevalence of autism in the United States is approximately 1 in 54 children. This means that the odds of having a child with autism are less than 2%.
A great deal of evidence supports the idea that genes are one of the main causes of or a major contributor to ASD. More than 100 genes on different chromosomes may be involved in causing ASD, to different degrees. Many people with autism have slight changes, called mutations, in many of these genes.
Autism is not an illness
It means your brain works in a different way from other people. It's something you're born with. Signs of autism might be noticed when you're very young, or not until you're older. If you're autistic, you're autistic your whole life.
But a large 2014 study based on Swedish medical records hinted that the odds of autism among children born to fathers older than 45 are about 75 percent higher than for children born to fathers in their early 20s.
For starters, a recent study, partly funded by Autism Speaks, found that in families with one or more children with ASD, the chances that a baby sibling will develop autism are much higher than previously thought. In fact, the odds were around one in five, or 20 percent.
In the United States, prenatal genetic testing (PGT) for Autism Spectrum Disorders (ASD) is currently available via clinical genetic services. Such testing may inform parents about their unborn child's risk for ASD, prepare parents for the birth of an affected infant, and allow them to arrange for early interventions.
Scientists long thought that siblings born with ASD share more of their mother's genome than their father's. But CSHL Associate Professor Ivan Iossifov and Professor Michael Wigler have now shown that, in many cases, it's dad who might be playing a bigger genetic role.
The bottom line
If you already have one child with ASD, you have a 1 in 5 chance of your next child developing autism. If you have more than one child with ASD, the odds of having another child with ASD are even higher. Certain conditions, like ADHD, also appear to have some predictive value.
Autism Prevalence
Boys are four times more likely to be diagnosed with autism than girls. Most children were still being diagnosed after age 4, though autism can be reliably diagnosed as early as age 2.
It is estimated that 1 in 100 people in Australia have Autism. In 2018 there were 205,200 Australians with Autism, a 25.1% increase from the 164,000 in 2015 (Source: ABS SDAC 2018– Autism in Australia). This means that if you have Autism you are not alone.
Genes and Autism
Certain genetic variants are linked to a higher chance of a child being somewhere on the spectrum. Also, it takes fewer variants to predispose a boy to developing autism than it does a girl.
Over the years, services for autism have become more readily available. The availability of services has encouraged more people to seek a diagnosis in order to gain access to these services. Increase in parental age. Across the world, people are waiting longer to become parents.
While you can't prevent having a child with an autistic disorder, you can increase your odds of having a healthy baby by doing these lifestyle changes: Live healthy. Have regular check-ups, eat well-balanced meals, and exercise. Make sure you have good prenatal care, and take all recommended vitamins and supplements.
Depression isn't the only mental health factor that can influence pregnancy outcomes. High levels of stress during pregnancy may also be connected to autism in children. This connection appears to have the most impact when the parent experiences stress between weeks 25 and 28 of pregnancy.
Genetic factors, environmental chemicals, certain drugs and vaccines, maternal factors, and environmental stress may all be legitimate causes. Many conditions can present alongside autism, and dealing with them can help ensure a proper autism diagnosis.
In the largest study of its kind, researchers have shown that the risk of autism increases for firstborn children and children of older parents. The risk of a firstborn with an autism spectrum disorder triples after a mother turns 35 and a father reaches 40.
At the same time, firstborn children also showed an increased incidence — 30 percent more than second-borns and 70 percent more than those born third or later.
There are studies that suggest the average age of children diagnosed with autism is around three years old in both the United States (US) and in the United Kingdom (UK).