Accelerated head growth can predict autism before behavioral symptoms start

January 30, 2008

Children with autism have normal-size heads at birth but develop accelerated head growth between six and nine months of age, a period that precedes the onset of many behaviors that enable physicians to diagnose the developmental disorder, according to new research from the University of Washington’s Autism Center.

The study also indicates that this aberrant growth is present in children who have the early onset form of autism as well as those later diagnosed with the regression type of the disorder, according to Sara Webb, who led the research.

“We know there are a number of risk factors for autism, and if we can pinpoint them we have better ways of identifying children at risk so we can get them into prevention or monitoring,” said Webb, a UW research assistant professor of psychiatry and behavioral sciences.

“This abnormal or accelerated rate of head circumference growth is a biological marker for autism. It occurs before the onset of behavioral symptoms at 12 months of age such as a child’s failure to respond to their name, a preoccupation with certain objects, not pointing to things, a lack of interest in other people and the absence of babbling.

“By itself, head growth is not an indicator of autism,” she said, “because kids are going to be getting bigger and development is so variable. However, if you notice it and some of these other symptoms, it is a red flag to seek evaluation.”

She said is it important understand that the data used in this study were based on three measurements made during the first three years of life, not from single point in time. To do this, the researchers obtained the medical records of 28 boys who had been diagnosed with autism spectrum disorder between the ages of 3 and 4 at the UW Autism Center and eight boys with developmental delay. All of the boys were participating in a larger longitudinal study.

Infant head measurements are typically done on a regular basis by pediatricians through the first 18 months of life, but are not reliably done after that. Head circumference is calculated from the brow, or ridge above the eyes, around to the bony bump on the back of the skull and back around to the brow. Three measurements, including at birth, were required to chart the growth of each child and compare it with the range of normal development.

Webb said in most cases parents would have a difficult time detecting abnormal growth because there is a range of normal head sizes. Approximately 20 percent of children with autism have abnormally large head sizes, or what is called macrocephaly.

“Some of the children in our study started with a very small head size and later their growth accelerated. What we are looking for is disproportionate growth in children compared to the rest of their body. In this study nearly 60 percent of the autistic children had accelerated growth but only six of the children met the criteria for macrocephaly.”

Webb said she sees this information being used by pediatricians to screen children and refer them earlier rather than later for evaluation and intervention before other symptoms develop. The UW researchers plan to further explore the implications of abnormal head size as part of a larger autism prevention study of 200 infants at high risk for the disorder that has just started. These youngsters have older siblings already diagnosed with autism and have a one in five chance of developing the disorder, which has a strong genetic component. The typical risk for autism is now believed to be one in 150.

Earlier research at the UW Autism Center by its founding director Geraldine Dawson showed that accelerated head growth in children with autism slows down in the second year of life and this deceleration coincides with a with a period of worsening symptoms of autism.

Source: University of Washington

Explore further: Neuroscientist sees disease-fighting potential in brain organoids

Related Stories

Neuroscientist sees disease-fighting potential in brain organoids

December 12, 2018
Human brain disorders have always presented researchers with a daunting challenge. They're hard to study in laboratory mice because they affect the very organ that separates us from animals. And they're difficult to study ...

Drug candidate may recover vocal abilities lost to ADNP syndrome

November 15, 2018
Activity-dependent neuroprotective protein syndrome (ADNP syndrome) is a rare genetic condition that causes developmental delays, intellectual disability and autism spectrum disorder symptoms in thousands of children worldwide. ...

Boys with regressive autism, but not early onset autism, have larger brains

November 28, 2011
In the largest study of brain development in preschoolers with autism to date, a study by UC Davis MIND Institute researchers has found that 3-year-old boys with regressive autism, but not early onset autism, have larger ...

Small changes to a child's head size should not concern parents

May 18, 2015
Measuring the size of a child's head is done routinely worldwide to screen for possible learning or developmental problems but new research out today [18 May] suggests that differences within the normal range of measurements ...

Scientists find mechanism for altered pattern of brain growth in autism spectrum disorder

July 15, 2015
As early as 1943, when autism was first described by psychiatrist Leo Kanner, reports were made that some, but not all, children with autism spectrum disorder have relatively enlarged heads. But even today, more than half ...

Discovering Autism: An unsettling boom

December 19, 2011
Amber Dias couldn't be sure what was wrong with her little boy.

Recommended for you

Discovery of novel mechanisms that cause migraines

December 17, 2018
Researchers at CNRS, Université Côte d'Azur and Inserm have demonstrated a new mechanism related to the onset of migraine. They found how a mutation that causes dysfunction in a protein which inhibits neuronal electrical ...

Small-scale poultry farming could mean big problem in developing countries

December 16, 2018
Small-scale farming in developing countries provides those in rural communities with income and access to protein, but it may have a large impact on antibiotic resistance, according to a new University of Michigan study.

RNA processing and antiviral immunity

December 14, 2018
The RIG-I like receptors (RLRs) are intracellular enzyme sentries that detect viral infection and initiate a first line of antiviral defense. The cellular molecules that activate RLRs in vivo are not clear.

Faster test for Ebola shows promising results in field trials

December 13, 2018
A team of researchers with members from the U.S., Senegal and Guinea, in cooperation with Becton, Dickinson and Company (BD), has developed a faster test for the Ebola virus than those currently in use. In their paper published ...

Urbanisation and air travel leading to growing risk of pandemic

December 13, 2018
Increased arrivals by air and urbanisation are the two main factors leading to a growing vulnerability to pandemics in our cities, a University of Sydney research team has found.

Drug targets for Ebola, Dengue, and Zika viruses found in lab study

December 13, 2018
No drugs are currently available to treat Ebola, Dengue, or Zika viruses, which infect millions of people every year and result in severe illness, birth defects, and even death. New research from the Gladstone Institutes ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.