Scientists identify gene mutation in
autism
December 17, 2006
PARIS (Reuters)
French scientists have identified
genetic mutations in a small number of children with autism which
could provide insight into the biological basis of the disorder.
They sequenced a gene called SHANK3
in more than 200 people with autism spectrum disorders (ASD), which
includes autism, and found mutations in the gene in members of three
families.
ASD covers a range of problems that
affect communication, social interaction, verbal skills and
behavior.
"These mutations concern only a
small number of individuals, but they shed light on one gene ...
that is involved in autism spectrum disorders," Thomas Bourgeron, of
the Pasteur Institute in Paris, said in a report in the journal
Nature Genetics.
ASD, which affect six out of 1,000
children, range from mild to severe forms. The disorders are caused
by chromosomal rearrangements in 3 to 6 percent of cases.
In people with cognitive deficits
and with autistic behavior a part of their chromosome 22 is often
affected. That region contains the SHANK3 gene.
In all three families identified in
the study, the researchers found they had various types of mutations
in the gene. Two brothers in one family had small deletions, while
another child in a different family had significant deletions.
A girl with a deletion of SHANK 3
in the third family suffered from autism while her brother, who had
an additional copy of the gene, had a mild form of autism called
Asperger syndrome.
The cause of autism is unknown. It
usually develops before the age of 30 months. A minority of autistic
children, who are known as autistic savants, show remarkable
artistic, musical or mathematical skills.
The protein encoded by SHANK3
interacts with other proteins called neuroligins, which have a role
in giving impulses to the brain, spinal column and nerves.
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