Vision Abnormality Seen in Close Relatives of Autism
MONDAY, Aug. 2 (HealthDay News) -- In another sign that autism
is at least partly inherited, a new study reveals that close
relatives of people with the disorder share something in common:
their eyes are much more likely than those of other people to
"There are brain abnormalities that run in families with autism," said study co-author John A. Sweeney. "These findings might be telling us that there's an important genetic contribution to autism."
The causes of autism, which affects an estimated one in 110
children in the United States, are unclear, according to the U.S.
Centers for Disease Control and Prevention. The number of children
diagnosed with the disorder has risen in recent years, but it's not
clear if that's largely due to more awareness or some other factor,
such as something in the environment around these children.
Previous research has suggested that family members of autism
patients are more likely to have some minor brain impairments than
other people, said Geraldine Dawson, chief science officer of
Autism Speaks, an advocacy organization.
In the new study, researchers looked for signs of eye
abnormalities that are common in people with autism. They often
have difficulty tracking moving objects in the first milliseconds
that they look at those objects, explained Sweeney, director of the
Center for Cognitive Medicine at the University of Illinois at
The abnormalities are minor and probably have no significant
impact on vision, Sweeney said. "These parents are walking around
fine, and it's unlikely that these [abnormalities] are going to
affect anyone's life."
Still, the vision abnormality suggests that something has gone
awry in the brain.
Sweeney and colleagues studied the eye movements of 57 close
relatives -- 42 parents and 15 siblings of people with autism. They
compared them to 40 other people who were similar to them in age,
gender and IQ but weren't close relatives of people with
More than 50 percent of the family members of people with autism
showed different signs of abnormal eye movements, Sweeney said. In
the general population, about 5 percent of people might have the
abnormalities, he added.
Essentially, the study suggests relatives of people with autism
share an abnormality in the brain that, for them, didn't fully
develop into autism.
Sweeney acknowledged that the study doesn't shed light on
exactly how responsible genetics are for autism. Still, the
findings fit in with research "that suggests the problems in autism
are much more the results of genetic than environmental factors,"
The study also provides evidence that the genes thought to carry
the risk for autism specifically affect parts of the brain such as
the cerebellum and frontal cortex, Dawson said.
The study findings are published in the August issue of the
Archives of General Psychiatry.
For more on
autism, try the U.S. National Institute of Neurological Disorders and Stroke.
Copyright © 2010
. All rights reserved.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.