Early Signs of Autism Identified in Infants
Findings Could Lead to More Effective Treatment
April 29, 2005 -- Canadian researchers say they can recognize the early
in children as young as
6 months old, and they hope their findings will lead to
In their ongoing study that now includes autism centers across 14 cities in
Canada and the U.S., the researchers are following the progression of younger
siblings of children with autism.
According to the National Alliance for Autism Research, a child born into a
family in which an older child has been diagnosed with autism is 50 times more
likely to develop the disorder than a child with no afflicted siblings.
In this study, researchers show that by age 1, siblings who are later
diagnosed with autism may be distinguished from other siblings by early
"This is groundbreaking work that is pushing the frontier of what we
know about the biological nature of autism, and why it emerges so early in
life," says researcher Lonnie Zwaigenbaum, MD, of Ontario's McMaster
University. "Our hope is that it will lead to the development of new and
earlier treatments that could make a huge difference for these
High-Risk Kids Followed From Birth
Autism is typically diagnosed in children around the age of 2 or 3 years,
but parents often have concerns about developmental delays much earlier. There
is strong evidence that autism has its origin in
write the authors.
In an effort to better understand the early signs of autism, Zwaigenbaum and
colleagues have been observing more than 200 younger siblings of children with
autism, many of whom have been followed from birth.
They developed a 16-point observational checklist called the Autism
Observational Scale designed to map the development of infants as young as 6
Specific markers include making infrequent eye contact, not smiling in
response to smiles from others, and, in older children, exhibiting
Even as early as 6 months of age, the researchers found that certain
behaviors tended to distinguish siblings later diagnosed with autism from
siblings who developed normally. These behaviors included passivity and a
decreased activity level at 6 months of age, followed by extreme irritability,
a tendency to fixate on objects, reduced social interaction, and lack of facial
At 1 year, these same children also tended to have difficulty with language
and communication, and they used fewer gestures.
Zwaigenbaum noted that almost all of the children in the study who were
diagnosed with autism by age 24 months had seven or more of these markers by
the time they were a year old.
The findings are reported in the latest issue of the International
Journal of Developmental Neuroscience.
While the checklist may be useful for recognizing signs of autism in very
high-risk children like the ones in the study, its relevance as an
observational tool for other children is not yet known.