"Little glitches in the DNA of people with autism suggest that the disease might be caused by as many as 100 different genes, researchers reported Thursday.
The study is one of several new reports on autism in recent months, which have shown the disease is far more common and more complex than many experts had believed.
"These findings certainly complicate the search for genes contributing to autism. These are rare changes, dispersed across the genome, and they tell us that autism may be the final common path for many different genetic abnormalities," said Dr. Thomas Insel, director of the National Institute for Mental Health, which helped fund the study.
The small changes are not what people usually think of as genetic mutations but are called copy number variations -- extra copies or missing stretches of DNA.
For instance, one child with Asperger's syndrome was missing DNA from a stretch of 27 genes.
The findings suggest that autism spectrum disorder may involve 100 or more genes, the researchers report in Friday's issue of the journal Science."
"Usually, tests of DNA of people with diseases show that everyone in a family who has the disorder carries the same mutation or pattern of mutations.
But that's not the case here. The researchers found numerous spontaneous mutations in 14 of 195 people with autism spectrum disorders compared to two of 196 unaffected people.
And of the 14 autism patients with mutations, only two had relatives with autism.
"Our results show conclusively that these tiny glitches are frequent in autism, occurring in at least 10 percent of cases, and primarily in the sporadic form of the disease, which accounts for 90 percent of affected individuals," Sebat said in a statement.
Dr. Jeffrey Lieberman, chairman of the department of psychiatry at Columbia University Medical Center in New York, said such work does not answer one overwhelming question about autism -- what causes these genetic changes in the first place."
I also heard about this in National Public Radio.
1 comment:
I have read so many opinions on what 'causes' autism that sometimes I think my brain is going to pop. I read something and think 'Yes I can go with that' and then I read something else and I think, Yes I can go with that too'.I have always thought that there were many possible reasons for the occurrence of autism and the research that you discussed appears to show this.Believing in the possibility of so many causes has at times made me feel gullible and stupid,thank goodness for research which constantly raises our awareness.
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