vs. Essential Autism
From Pediatric News October 2003 , Vol. 37 ,
By Sally Koch Kubetin.
Columbia, MO. - Autistic children with dysmorphic
facial features have a different variant of the
disorder than do their nondysmorphic peers, Dr.
Judith Miles said at a meeting on common pediatric
problems sponsored by the University of Missouri-Columbia.
Children with what geneticists call dysmorphic
features need not be
unattractive. "These can be cute kids, but
on close inspection one can see
that something went awry during the first part
of pregnancy," said Dr.
Miles, who is a professor in the department of
child health at the
The dysmorphia can be subtle. Some examples include
hair whorl, frontal hair upsweep, medial left
eyebrow flair, long flat
philtrum with attenuated philtral ridges, broad
forehead, pointed chin,
small face, pointed finger nails, and small mouth.
Researchers only recently have begun to examine
the clinical and
genetic heterogeneity of autism and have found
some significant differences
in presentation. "About 30% of our autism
clinic population [78/260
children] have complex autism," she said.
In these children, autism occurs in combination
with dysmorphic facial
features, microcephaly, and/or structural brain
abnormalities on magnetic
resonance imaging. The ratio of boys to girls
with complex autism is close
to 1:1, she reported.
The other variant of the disorder is essential
children do not have dysmorphic features, small
heads, or structural brain
abnormalities; many more boys than girls have
"Think of complex autism as being a sort
of birth defect while
essential autism is more of a biochemical disorder
that may involve
abnormalities of neurotransmitters," said
Dr. Miles, who is a geneticist.
Children with complex autism have higher rates
of mental retardation
and seizures than do those with essential autism.
However, essential autism
is more likely to run in families.
In a retrospective study, Dr. Miles collaborated
with Matthew P.
Stoelb, Ph.D., of the department of education
at the university, to look at
a group of 19 autistic children.
Dr. Stoelb conducted intensive, early, one-on-one
therapy with the
children to help them acquire speech and overcome
delays; he worked with the children 22 hours weekly
for 1 year.
Dr. Miles then applied her observations about
dysmorphia in autism to
the children's outcomes at the end of therapy.
Findings from a linear
regression model showed that the presence of dysmorphia
was the most
statistically significant predictor of failure
to acquire language.
Increased Autism Prevalence Is Not An 'Epidemic'
prevalence of autism over the past decade and
a half does not represent an
epidemic, according to Dr. Miles.
She noted that the prevalence of autism has increased
the 15 years that she has been in the field. Autism
affected 4-5 of every
10,000 children during the years before the 1990s;
over the course of the
1990s, the prevalence increased to 16.8 cases/10,000
Some parents are concerned that the increased
prevalence of autism
reflects an epidemic, one that may result from
an environmental factor such
as the use of mercury in vaccines. However, it
is unlikely that the
increased prevalence is anything other than the
result of detecting subtler
variants of autism.
"There are no epidemics in genetics, and
autism has an inheritability
index of 90%," she said. (Editor: See next
article for an opposite point of view)
Many of the autistic children who are diagnosed
now have higher IQs
than those diagnosed 15 years ago. "These
are the kids whom we did not pick
up before because they were functioning well,"
Copyright © 2003 by International Medical
News Group, an Elsevier