Posted by Ellena
on November 28, 2000 at 15:12:28:
Nov. 27, 2000 (Washington) -- Scientists have long theorized that about
15 different genes play a role in who is born with the severe brain disorder
autism -- and now they've finally found one of those genes.
A study of 57 autism patients found that 40% carry a mutated version of
the HOXA1 gene, which plays a crucial role in early brain development,
University of Rochester scientists reported Monday.
Children need to inherit just one copy of the mutated gene from one
parent to have autism. In fact, scientists found only one patient, a very
severe case, who inherited a copy of the bad gene from both parents,
suggesting that when that happens the fetus usually dies, said lead
researcher Patricia Rodier, who heads the university's National Institutes
of Health (NIH)-funded autism research center.
The NIH called the finding a significant step in understanding what
predisposes people to developing autism. More than 400,000 Americans
have the brain disorder, characterized by profound social withdrawal,
repetitive behavior and inability to communicate. Research suggests it's
caused when something goes wrong during critical fetal brain
development -- a theory that the gene discovery, which was published in
the December issue of the journal Teratology, supports.
Why don't parents who harbor the defective gene have autism
themselves? Some do have very subtle symptoms, suggesting that
something else, perhaps some other gene, keeps the autism-related
gene in check, Rodier said.
HOXA1 is one of a family of genes vital to early embryo development
because genes in the group turn on or off other genes. HOXA1's specific
role is in brain development. Mice who lack this gene have brainstem
damage, malformed ears and other classic signs of autism -- one reason
Rodier's research team decided to check the gene's role in people.
It's not the kind of gene that could ever be fixed with gene therapy. But
the discovery may help doctors unravel just how the brain changes when
HOXA1 is abnormal, Rodier said.
"If you figure out the brain changes, you're on your way, we hope, to
finding better treatments," she said.