Early Signs of Autism Identified in Infants

Findings Could Lead to More Effective Treatment

Medically Reviewed by Brunilda Nazario, MD on April 29, 2005
From the WebMD Archives

April 29, 2005 -- Canadian researchers say they can recognize the early signs of autism in children as young as 6 months old, and they hope their findings will lead to better early treatments for the disorder.

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 developmental behaviors.

"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 children."

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 abnormal brain development early in prenatal life, 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 months.

Specific markers include making infrequent eye contact, not smiling in response to smiles from others, and, in older children, exhibiting delayed language skills.

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 expression.

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.

"Many of these behaviors are pretty common in early development, so they are not necessarily a cause for concern," Zwaigenbaum tells WebMD. "The next step is to take this experience working with high-risk infants out to the general community to see if these observations have meaning."

In the meantime, the findings may immediately lead to an earlier suspicion of autism and possibly earlier intervention in children at high risk.

"The message is that we need to start working with these kids as early as possible instead of telling families that they should wait and see what happens," Zwaigenbaum says.

Autism expert Andy Shih, PhD, tells WebMD that it is increasingly clear that early intervention can make a big difference in the outcome of children with autism. Shih is chief science officer for the National Alliance for Autism Research.

"The evidence suggests that early behavioral interventions can actually translate into better prognosis for these children," he says. "I foresee this research having a tremendous impact on the diagnosis and care of children with autism. The ability to provide even earlier interventions would have a tremendous impact on the quality of life of many children out there and their families."

Show Sources

SOURCES: Zwaigenbaum, L. International Journal of Developmental Neuroscience, April 2005; vol 23: pp 143-152. Lonnie Zwaigenbaum, MD, developmental pediatrician, department of pediatrics, McMaster Children's Hospital, McMaster University, Hamilton, Ontario, Canada. Andy Shih, PhD, chief science officer, National Alliance for Autism Research.

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