Neurologists and child development specialists have learned quite a lot about
autism and its possible causes in recent years, but much remains poorly
understood. It is usually diagnosed “late” – around the age of three or four,
and the tests are still subjective.
Now Weizmann Institute of Science
researchers, along with colleagues at Carnegie Mellon University and the
University of California, San Diego, have found a method that can identify a
biological sign of autism in young toddlers that could lead to early diagnosis.
The research recently appeared in Neuron.
By scanning the brain activity
of sleeping children, the scientists discovered that autistic brains exhibited
significantly weaker synchronization between areas tied to language and
communication, compared to that of non-autistic children.
biological signs of autism has been a major goal for many scientists around the
world, both because these may allow early diagnosis, and because they can
provide important clues about the causes and development of the disorder,” says
post-doctoral fellow Dr. Ilan Dinstein, working with Prof.
who headed this study at the Rehovot institute’s neurobiology department. While
many scientists believe that faulty lines of communication between different
parts of the brain are involved in autism disorders, there was no way to observe
this in very young children, who are unable to lie still inside a functional MRI
scanner while they are awake.
But work by Malach’s group and other
research teams pointed to a solution. Their studies had shown that even during
sleep, the brain does not actually switch off. Rather, its electrical activity
switches over to spontaneous fluctuation coordinated across the brain’s two
hemispheres; each point on the left is synchronized with its corresponding point
in the right.
In sleeping autistic toddlers, the fMRI scans showed
lowered levels of synchronization between the areas known to be involved in
language and communication.
This pattern was not seen either in children
with normal development or in those with simple delayed language development. In
fact, the researchers found that this synchronization was strongly tied to the
autistic child’s ability to communicate: The weaker the synchronization, the
more severe the symptoms of autism. On the basis of the scans, the scientists
were able to identify 70 percent of autistic children between the ages of one
Dinstein concludes: “This biological measurement could help
diagnose autism at a very early stage. The goal for the near future is to find
additional markers that can improve the accuracy and reliability of the
diagnosis.”Moldy threat to health
Black mold on walls is not only
unesthetic and smelly; this growth on moist surfaces can also be harmful to
health. University of Cincinnati researchers write in the August issue of Annals
of Allergy, Asthma & Immunology that babies who live in “moldy” homes are
three times more likely to develop asthma by age seven than those living in
homes without such conditions.
“Early life exposure to mold seems to play
a critical role in childhood asthma development,” says Prof. Tiina Reponen, lead
study author and an expert in environmental health at the Ohio university.
“Genetic factors are also important to consider, since infants whose parents
have an allergy or asthma are at the greatest risk of developing
The university and Cincinnati Children’s Hospital Medical Center
researchers analyzed seven years of comprehensive data for 176 children to
evaluate the effects of mold exposure in early life as part of a long-term
population-based study that included more than 700 children from the greater
Cincinnati area. They analyzed the effects of environmental particles on
childhood respiratory health and allergy development, and identified children
who already in infancy were identified as being at high risk of developing
Mold exposure levels were measured using a DNA-based analysis
tool developed by the US Environmental Protection Agency – the environmental
relative moldiness index, which combines results of the analysis of 36 different
types of mold. Eighteen percent of the children were found to be asthmatic at
age seven. It is estimated that about 9% of school-age children in the US will
develop asthma; however, studies have shown that rates are often higher in
children from poor urban families. The disease cannot be accurately diagnosed
until age seven.
”The symptoms of pediatric asthma range from a nagging
cough that lingers for days or weeks to sudden shortness of breath and wheezing
that requires emergency treatment,” says allergist Dr. David Bernstein, a study
co-author. “If a young child’s symptoms persist, that’s a clue that it could be
Common symptoms of asthma include coughing, especially at night;
a wheezing or whistling sound when exhaling; difficulty breathing or rapid
breathing that causes the skin around the ribs or neck to pull in tightly; and
frequent colds that settle in the chest.
“This study should motivate
expectant parents – especially if they have a family history of allergy or
asthma – to reduce the mold burden in their homes,” adds Reponen.