2007年VOA标准英语-Multi-Country Gene Study Points to Causes of Au（在线收听）

By Carol Pearson
Washington, DC
20 February 2007
 
watch Autism report

Scientists working to solve the mysteries of autism say their research points to genetic causes. The results come from the largest study ever done on the disorder. The study looked at the genes of almost 1,200 families.  Each had at least two autistic children.  VOA's Carol Pearson has more.

 
Autism was first believed to be caused by bad parenting
Autism is a complex neurobiological disorder.  It affects people throughout the world. Autism occurs in all racial, ethnic, and social groups and is four times more likely to strike boys than girls.

Theresa and Chris Waddell have two boys with mild autism. Theresa says they are both different. "Autism is such a wide spectrum.  Every child presents [manifests the symptoms] differently."

Which is why it is really a group of disorders called autism spectrum disorders, or ASD.  ASD impairs a person's ability to communicate and relate to others. Those most severely affected cannot even talk.

Scientists suspected a genetic cause -- and this may have been confirmed by a new international study. Computers that can read billions of DNA signals in minutes showed specific genes and genetic abnormalities unique to these families.

 
Joseph Buxbaum
Geneticist Joseph Buxbaum is one of the principal investigators in the study.  He explains what they found. "A smoking gun that implicates a series of genes that all work together, and may together cause autism."

The researchers say the new study also shows environmental toxins do not cause autism spectrum disorders. Professor Buxbaum adds, "The evidence suggests autism is over 90 percent caused by genes."

And not by just one gene but by combinations of genes that may cause the different degrees and kinds of autism.

Buxbaum says it is just the beginning, "We have the beginnings of the beginning, I would call it.  The message here is that there is great hope now." The researchers say they hope their findings will lead to drugs that could reverse autism in five to 10 years.

The researchers will now focus on the many genes they've identified in the autism families hoping to find the exact  roles of each gene or abnormality and how they interact.