Researchers have made an important discovery in the search for
answers to the mystery of autism, according to a large study in
U.S. quoted by media reports on Thursday.
They found that a rare genetic variation dramatically raises the
risk of developing autism. In fact, kids with the genetic flaw have
a 100-fold increased chance of developing autism than kids without
it.
The study's senior author, Dr. Mark Daly, of the Massachusetts
General Hospital Center for Human Genetic Research, said that those
people who have this chromosomal abnormality have "a very, very
high risk of autism."
The researchers found that a segment of chromosome 16 is either
missing or duplicated in about one percent of individuals with
autism or related disorders.
"We've provided very compelling evidence that this particular
small stretch of the genome provides an important clue to the
biological roots of autism," Dr. Mark Daly said.
When the biological pathways involved are figured out,
scientists can try to design drugs to target chemicals in the brain
to treat autism.
Autism, a complex, poorly understood disorder, is characterized
by repetitive behaviors and poor social interaction and
communication skills. The research has mainly centered on genetic
causes, and on whether it could be caused by the mercury-based
preservative once used in childhood vaccines, which has been
repeatedly discounted.
The number of children diagnosed with autism has risen in recent
years to as many as one in 150 American children, but experts are
unsure whether its prevalence really is increasing or the trend is
due to a broader definition of autism.
(Agencies via Xinhua News Agency January 11, 2008)