New research may shed more light on the disorder
By Deborah Jeanne Sergeant
When parents receive a diagnosis of autism spectrum disorder for their child, it’s only natural to want to know why their child will face these challenges.
A new study from University of California San Diego School of Medicine has looked at possible reasons behind autism to include genetics, environmental factors and prolonged activation of the cellular stress response at important developmental periods.
Potentially, early interventions could prevent or at least minimize two of the three factors, leaving only genetics as an immutable factor, since it appears that autism is not the result of only genes or only a certain environmental exposure, but is the outcome of a few different factors.
Researchers compared the possible reason behind autism as having similar action as the development of phenylketonuria (PKU), a genetic disorder that causes intellectual disability. If PKU is discovered and treated early, nearly all children experience typical development despite the gene. The thought is that if these three factors are the cause for autism, interrupting the causes that doctors can affect will reduce cases and help lower the extent of disability in children who will experience autism.
Healthcare providers would need to institute screening protocols for parents and newborns to assess risk for autism.
The study’s findings indicate that up to 50% of all cases of autism could be prevented or mitigated with prenatal and early interventions. Even now, early intervention strategies help children achieve better outcomes.
“There is not one known cause of autism, but what we do know is there is a variety of causes that are genetic and environmental,” said Nicole M. DeRosa, doctor of psychology, licensed behavioral analyst and chief clinical officer at Kelberman in Utica.
The University of California study looks at autism as a possible neurometabolic and neuroimmune condition, which may help more providers and researchers look at possible tools for earlier diagnosis and interventions that can help.
“We’re still learning more and more,” DeRosa said. “It continues to be a high area of research to identify known causes. Potential risk factors are what we know more about it, like a genetic component, such as if one sibling has it advanced parental age and complications at birth. But it’s important to recognize that if those risk factors are present, it won’t mean autism will be diagnosed.”
DeRosa advises parents to check the website of the Centers of Disease Control and Prevention for developmental milestones (www.cdc.gov/act-early/milestones) and if they notice any issues, they should discuss their observations with their child’s pediatrician.
The inheritability of autism is only one aspect of how autism is caused.
Physician Lou Pellegrino, associated professor of pediatrics with Upstate Medical University Golisano Center for Special Needs, said that “in twin studies of autism, there is a 98% concordance between identical twins, meaning that if one twin has autism there is a 98% likelihood that the other will as well. In families that have one child with autism, the recurrence risk of having another child with autism is about 10%; if they have more than one child with autism, the recurrence risk rises to 30%. This is compared to an autism rate of about 3.2% in the general population.”
Gene mutations are another contributing cause of autism spectrum disorder. Pellegrino said that more than 100 different genes have been associated with autism, but no one gene dominates.
“As many as 30% of children with autism spectrum disorder may a specific genetic mutation that can be identified by genetic testing,” Pellegrino said. “Currently, the recommended first-line test is called whole exome sequencing and is most often obtained as a cheek swab.”
He said that factors that may increase risk can include prenatal exposure to certain drugs, increased parental age, maternal autoimmune conditions, infection during pregnancy, prematurity and low birth weight.
Of course, this does not mean that each child with these risks will have autism, but they do increase risk.
Physician Chris Lucas, vice chair for hospital psychiatry and medical director of the bio-behavioral health unit at Upstate Medical University, said that environmental factors could include air pollution, water pollution, chemicals and pesticides.
“It’s probably more direct exposure, but there’s increasing epigenetic effects as to how well a gene is expressed,” Lucas said.
He added that there’s not a great deal that parents can do, but having children sooner than later is a good idea.
Lucas emphasized that vaccines do not cause autism and are not even correlated with autism.
“Theres’ absolutely no evidence and numerous studies disproving the idea,” he said. “The original study was flawed and there’s far more dangers about not being vaccinated than vaccinated.”
Researcher Andrew Wakefield, who published the now-debunked study, looked at only 12 children in 1998 in a non-controlled study regarding the routine childhood “MMR” (measles-mumps-rubella) vaccine containing thimerosal, a preservative used in MMR vaccines to prevent growth of bacteria and fungi.
Thimerosal was removed from the US vaccine supply in 2001. Infants typically receive MMR at about the developmental stage when autism traits present (although well-trained experts can spot autism traits much earlier). Parents whose children receive an autism diagnosis want answers and try to look for anything that happened that could be the cause.
“Many millions of births have been studied in Scandinavia and there’s no evidence whatsoever that vaccination has anything to do with autism,” Lucas said. “There’re 250 genes that might be implicated is not a great answer for parents who want to say, ‘It was caused by this.’”
Part of the reason that parents want to blame vaccination is that many of the vaccines are administered at about the time many parents notice that their child is not meeting milestones.
“About 20% of autism has regression,” Lucas said. “The child loses some skills-abilities they have and that happens around ages of 2 to 3 years which is many of the vaccines are being given. It’s one type of autism that exhibits at that age. Most types are right from the beginning and experts can fairly readily identify.”
The Associations for Autism and Neurodiversity states on its website that more than 40 high-quality studies of more than 5.6 million children across 25 years reach the same conclusion that vaccines do not cause autism.
This viewpoint is supported by the American Academy of Pediatrics, the American Public Health Association, the American Medical Association, the Infectious Diseases Society of America, and more than 50 other national organizations.