Well documented causes of secondary ASD include conditions such as tuberous sclerosis, down syndrome, Fragile X syndrome (FXS), and some congenital infections (e.g., cytomegalovirus) (5–7).
Research suggests that autism genes are usually inherited from the father, despite some research showing it's passed down from the mother.
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.
Research indicates that genetics are involved in the vast majority of cases. Children born to older parents are at a higher risk for having autism. Parents who have a child with ASD have a 2 to 18 percent chance of having a second child who is also affected.
Genetics. Genetic factors may be the most significant cause of autism. Early studies of twins had estimated heritability to be over 90%, meaning that genetics explains over 90% of whether a child will develop autism.< This may be an overestimation, as later twin studies estimate the heritability at between 60 and 90%.
Key Autism Statistics & Facts
In 2023, the CDC reported that around 1 in 36 children in the U.S. is diagnosed with autism. Autism prevalence has increased 178% since 2000. The country with the highest rate of diagnosed autism in the world is Qatar, and the country with the lowest rate is France.
But the question in our mind is whether is it detectable even during pregnancy. Recent studies have shown that autism can be detected during pregnancy as early as the second trimester.
Several risk factors present during pregnancy have been associated with autism. Some, like older parental age and use of antidepressants, have strong research support. Others, such as Tylenol (acetaminophen) use and exposure to environmental toxins, need more investigation.
Autism may stem from a different — and larger — set of genetic mutations in women than it does in men, according to a new study1. The findings support a growing body of evidence suggesting that women require a bigger genetic hit than men do to have conditions that affect brain development, including autism.
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.
A number of studies have suggested that it takes a bigger genetic 'hit' to cause autism in girls than in boys — on average, girls who have autism tend to have more gene changes than boys do.
There are other brain disorders that mimic autism symptoms, like ADHD and anxiety disorders, including selective mutism. Autism can be misdiagnosed as another disorder with some shared symptoms.
Autism is a lifelong developmental disability which affects how people communicate and interact with the world. More than one in 100 people are on the autism spectrum and there are around 700,000 autistic adults and children in the UK.
Doctors look at the child's developmental history and behavior to make a diagnosis. ASD can sometimes be detected at 18 months of age or younger. By age 2, a diagnosis by an experienced professional can be considered reliable. However, many children do not receive a final diagnosis until much older.
Many children show symptoms of autism by 12 months to 18 months of age or earlier. Some early signs of autism include: Problems with eye contact. No response to his or her name.
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%.
There's no way to prevent autism spectrum disorder, but there are treatment options. Early diagnosis and intervention is most helpful and can improve behavior, skills and language development. However, intervention is helpful at any age.
ASD occurs in all racial, ethnic, and socioeconomic groups. It is more than 4 times more common among boys than among girls.
A common question after an autism diagnosis is what is the cause of autism. We know that there's no one cause of autism. Research suggests that autism develops from a combination of genetic and nongenetic, or environmental, influences. These influences appear to increase the risk that a child will develop autism.
Results from Jilin City, where both mainstream and special school data were available, revealed a similar prevalence of autism in China to the West, at around 1%.
The extreme male brain theory posits that it is an overdevelopment in the male traits of cognition that causes ASD patients to over-systematize, leading to a breakdown of verbal and social capacities. Some studies have found correlations between fetal testosterone levels and ASD.
The most effective interventions available are behavioral therapies based on applied behavioral analysis (ABA). There are many different types of ABA to choose from based on your child's strengths and needs.