What causes autism? Researcher id 102 gene
associated with the condition
A large genetic study has given scientists a
deeper understanding of how genes cause changes in the brain that lead to
autism spectrum disorders.
- The
researchers analyzed more than 35,000 participant samples, including
nearly 12,000 samples from patients with ASD.
- Scientists
believe that genes and the environment were both involved in the
development of ASD, in which genetics played an important role.
In the largest
genetics study of its kind to date, scientists have identified 102 genes
associated with the risk of autism spectrum disorder (ASD).
The researchers also
learned more about which genes are associated with ASD and other disorders that
cause intellectual disability and developmental delay.
For the study, an
international team of researchers analyzed more than 35,000 participant
samples, including nearly 12,000 samples from patients with ASD.
The researchers used a
genetic technique called "exome sequencing," which looks at all
regions of a person's genetic information (or genome) that are translated into
proteins. This test can uncover rare genetic mutations that other methods may
not have.
Dr. Lonnie
Zwaigenbaum, a professor in the Department of Pediatrics at the University of
Alberta and chair of autism at the Stollery Children's Hospital Foundation,
called it an "exciting" study because it used sophisticated methods
and large sample sizes.
These allowed the
researchers to "identify more genes than ever before, leading to insight
into how these genes work and how they increase the risk of DEVELOPING,"
said Zwaigenbaum, who was not involved in the study.
The results were published in the journal
cell on January 23.
Better understand the genetics of ASD
ASD is a group of
neurological and developmental conditions that affect communication and
behavior. The type and severity of symptoms in patients with ASD vary widely.
Scientists believe
that genes and the environment were both involved in the development of ASD, in
which genetics played an important role.
"We know that
inherited and unique mutations in the genome are the primary source of risk for
developing ASD, but the specific cause of ASD is unclear," said Dr. Lori
J. Warner, director of the Center for Human Development. The Lindsay Foundation
Hope Center at Beaumont Children's Hospital in Royal Oak, Michigan, was not
involved in the study.
Although environmental
factors play a role in ASD, scientific learning has found no link between
receiving the vaccine and developing ASD.
The new study marks an
important step forward for scientists in understanding the genetic basis of ASD.
The researchers
identified genetic mutations and de novo mutations — mutations that occur
spontaneously when an egg or sperm is formed.
They also found that
the ASD gene found in the study can affect brain development or brain function.
They showed that the two main types of nerve cells are affected in ASD.
Of the 102 genes
identified in the study, 49 were associated with other developmental delays.
"Some genes
appear to be associated with the development of ASD, while others may increase
the risk of developing ASD and severe neurodevelopmental disorders,"
Warner said. "We don't fully understand this process yet, but
distinguishing ASD from other disorders is important for effective
treatment."
Zwaigenbaum says the
overlap between ASD and other neurodevelopmental disorders is consistent with
previous research.
"This study
reinforces that many genes may play a role in autism susceptibility, but also
have a broader role in early brain development," Zwaigenbaum said.
These genes "have
a wider expression of the developmental abilities and challenges of the
affected individuals."
Research points to treatment and diagnosis
As a result of this
study, scientists now have a better understanding of autism spectrum disorder,
but this kind of study also points to better ways to help children with an
autism spectrum disorder.
"The biggest
benefit of this type of study is to help researchers, families, and intervenors
better understand the actual role of genetic factors in the brain and body in
on-body development," warner said, "so that treatments can be
developed to improve or completely block the destructive changes that cause diseases
like ASD." ”
However, Zwaigenbaum
warns that the results of this study will not have immediate clinical benefits.
"A lot of
translational work is still needed to assess whether the results of this study
will directly inform assessment, diagnosis, or treatment," he said.
Still, he said the
results provide direction for future research into potential biological
therapies and genetic testing that can diagnose ASD early.
Warner said there are
currently some drugs approved for use in children with autism, but they target
symptoms such as anxiety or anxiety rather than the core social or behavioral
deficits of autism.
Early diagnosis is
another goal of the ASD study because "the sooner a child is identified
and properly assessed, the sooner families can receive the support they
need," Warner said.
However, ASD is a
complex disease, so genetic diagnosis isn't always that simple.
"While studies
like this continue to expand our understanding of the growing number of genes
associated with ASD, the reality is that even though the most sophisticated
genetic testing, most children with ASD rarely find genetic causes," said
Andrew Adesman, MD, director of developmental and behavioral pediatrics at
Cohen Children's Medical Center in Queens, N.Y., who was not involved in the
study.
However, he said
parents of children with autism still have value in seeking genetic testing,
especially as genetic technology advances.
"In terms of
diagnostic 'yields' from genetic testing, it has been growing steadily,"
Adelman said. "For this reason, parents of children with autism may want
to discuss with their pediatrician whether their child should undergo updated
genetic testing."
Without a simple test
for ASD, parents can still do something for their child.
"The most
important thing families and health care providers can do are understand the
risk factors and signs and symptoms of autism as early as
possible and connect with the services needed as soon as possible," Warner
said.