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  • A new study finds people with 1 of 4 genetic conditions have an increased chance of autism, but may not receive the evaluation, care, and services they need early enough in life.
  • According to the National Institute of Environmental Health ScienceS (NIEHS), scientists are still trying to understand why some people develop Autism spectrum disorder (ASD) and others don’t.
  • Risk factors include parental age at time of conception and prenatal exposure to air pollution, experts say.

Over half of people born with 1 of 4 genetic conditions experience symptoms of autism, despite not qualifying for a formal diagnosis, according to new research conducted at Cardiff University in the United Kingdom.

“Several genetic conditions have been linked to autism, and these conditions are increasingly being diagnosed within health services, yet information on behavioral outcomes has been previously lacking,” lead study author, Samuel Chawner, PhD, a post-doctoral research scientist at Cardiff University’s MRC Centre for Neuropsychiatric Genetics and Genomics, told Healthline.

“We wanted to do a detailed study to build the clinical evidence base of these autism-linked genetic conditions,” Chawner said.

The study’s findings show clinical services must adapt so people diagnosed with autism-linked genetic conditions aren’t mistakenly denied access to critical support services, researchers said.

And helping children early is key as a significant number of them are diagnosed with Autism spectrum disorder (ASD) in the United States.

“According to the most recent data from the CDC’s Autism and Developmental Disabilities Monitoring Network, the prevalence of autism spectrum disorder (ASD) is 18.5 per 1,000, or 1 in 54 children,” Dr. Alyson Gutman, a developmental and behavioral pediatrics specialist at Cohen Children’s Medical Center in New York, told Healthline.

Gutman was not involved in the research.

The international study analyzed data from 547 individuals previously diagnosed with 1 of 4 genetic conditions known as copy number variants (CNVs) associated with an increased chance of autism.

These CNVs are:

  • 22q11.2 deletion
  • 22q11.2 duplication
  • 16p11.2 deletion
  • 16p11.2 duplication

Researchers pooled data from eight separate clinical research centers that all used the Autism Diagnostic Interview-Revised (ADI-R) and IQ tests on study participants.

Findings suggest a high incidence of autism in people with these four genetic traits, ranging from 23 to 58 percent.

Chawner and the team also found over 50 percent of people with these genetic conditions who didn’t meet the full criteria for an ASD diagnosis still had increased levels of autism symptoms.

According to the Centers for Disease Control and Prevention (CDC), autism is a developmental condition that can cause “significant social, communication, and behavioral challenges.”

“ASD is a neurodevelopmental disability which involves impairments in social interactions and repetitive patterns of behavior,” Gutman said.

Gutman said that autistic children can present a wide range of symptoms that can include:

  • lack of eye contact
  • a preference to playing alone
  • difficulty making friends

“Children may exhibit repetitive movements, such as hand flapping or spinning, and repetitive language, such as repeating dialogue from videos,” Gutman added. “Other symptoms include having very narrow interests, difficulty with changes in routines, and being overly sensitive to sounds, textures, or smells.”

According to the National Institute of Environmental Health Sciences (NIEHA), scientists are still trying to understand why some people develop ASD and others don’t.

However, there are environmental risk factors that can increase the chance of having autism. These include:

  • advanced parental age at time of conception
  • prenatal exposure to air pollution or certain pesticides
  • maternal obesity, diabetes, or immune system disorders
  • extreme prematurity or very low birth weight

A recent study published in the Journal of the American Medical Association (JAMA) found pregnant people who used acetaminophen (Tylenol) birthed children with an increased chance of ASD.

There are genetic conditions associated with autism. Chawner said it’s still unknown whether different conditions cause different types of autism.

“Many in the field have previously hypothesized that different genetic conditions lead to different types of autism,” he said. “We, in fact, found small differences between genetic conditions, and we were surprised how variable clinical outcomes are within a genetic condition.”

Chawner also found that the differences in clinical outcomes within a genetic condition were greater than the differences between genetic conditions.

“To us this indicates that other factors are likely to play a more important role than the type of genetic condition in explaining outcome,” he said. “These possibly include additional genetic factors that modify clinical outcomes or environmental factors, such as access to healthcare and early educational support, and prenatal factors.”

“Early diagnosis for children with autism is critical because the sooner that child can get the support they need, the better their chances for positive outcomes as they grow,” Tom Frazier, PhD, chief science officer at Autism Speaks, said in an emailed statement.

Frazier emphasized that formal autism diagnosis can open the door to certain treatments.

He also said that children with “specific developmental delays like speech or motor issues” should be referred for services immediately without waiting for an autism diagnosis.

“This ensures that children can continue to make progress and develop early skills that help them reach their full potential,” he said.

According to Frazier, there’s no biological test available for autism.

The condition is clinically diagnosed using behavioral observation “such as the ADOS [autism diagnostic observation schedule], or for older children and adults, the ADI-R that was used in this study,” he said.

Frazier pointed out that in either case, it’s important for children diagnosed with autism to have genetic testing, as recommended by the American Academy of Pediatrics (AAP), to identify underlying genetic conditions.

On the other hand, children with genetic conditions can be evaluated for autism and related challenges, he said.

Even if a child doesn’t meet the criteria for a diagnosis of ASD, a developmental evaluation for children with a genetic disorder “can lead to identifying other conditions like social communication disorders, behavioral conditions or learning disabilities, and getting necessary supports and services in place that the child needs,” Frazier said.

According to Chawner, this study underscores the need to integrate genetic testing and autism diagnosis services so children with one of these CNVs can also be evaluated for ASD.

He emphasized the need “for greater awareness of genetics in psychiatry training and greater awareness of psychiatry in medical genetics training for medical professionals.”

Chawner specified other possible solutions, which include creating care pathways or services so that once a child receives results from testing that indicates they have a genetic condition linked to autism they get fast-tracked for an autism assessment.

“Also having psychology and psychiatry professionals embedded within medical genetic teams — medical genetics often has strong links to cancer or cardiology services but historically less so with psychiatry,” he said.

“A shift is needed in service delivery,” Chawner said.

A new study finds people with 1 of 4 genetic conditions have an increased chance of autism, but may not receive the evaluation, care, and services they need early enough in life.

Experts say this is because there isn’t sufficient integration between genetic and autism diagnosis services.

They also say one possible solution is creating service-care pathways that fast-track children with one of these genetic conditions for autism assessment.

Experts also say a shift toward embedding psychiatry or psychology professionals with medical genetics teams is needed to improve service delivery to autistic people.