Studies link autism to two genetic defects

I read this interesting account in the Los Angeles Times about genetic defects proposed to be responsible for autism. This account was written up by By Thomas H. Maugh II, L.A. Times staff writer.

"Researchers this week identified two separate genetic defects linked to autism, one that directly causes the disorder in about 1% of all cases and a second that may play a role in a much larger percentage of patients by increasing their susceptibility to environmental or other genetic influences."

Yes, I figured that at least Sometimes, environmental triggers had to play a role in the development of autism, seeing as so many different types of stressors may lead to the same brain outcome: autism.

"The findings offer hope that it may be possible to identify vulnerable children early in life and begin treatment to mitigate the effects of the disabling disorder, which is marked by poor language ability and strong social isolation. Autism now affects one in every 150 U.S. children."

That would be incredibly awesome.

"In the first study, headed by geneticist Mark J. Daly of Massachusetts General Hospital, a multi-center team called the Autism Consortium reported Thursday in the New England Journal of Medicine that deletions or duplications of a specific small segment of chromosome 16 increases the risk of autism one-hundredfold."

Wow. That sounds like it means that it could happen somewhat commonly, as small genetic errors are common and do not always get fixed.

"The genetic defect was found in children with autism but not in their parents, indicating that it was a spontaneous mutation that occurred sometime after fertilization. The location, called 16p11.2, is what is known as a genetic "hot spot," meaning it is unusually susceptible to such mutations."

The sometime after fertilization being hopeful news to those parents who get "blamed" by critics in having done something wrong, lifestyle-wise or emotionally!

"The deletions or repetitions were found in 24 of 2,252 people in families with at least one autistic member but in only two out of 18,834 people without the disorder."

It sounds like that means there is some genetic predispositioning in the parents. But that the "hot spot" usually is left intact or repaired in most offspring?

"The team is now trying to identify the specific gene involved."
"The second defect was originally identified in 2006 in four Amish children. Three groups of researchers independently reported today in the American Journal of Human Genetics that they had identified the same defect in much larger groups of subjects."
"The gene they found is called contactin-associated protein-like 2,or CNTNAP2, which produces a protein that allows brain cells to communicate with one another."
" 'This gene not only may predispose children to autism,' said Dr. Daniel Geschwind of UCLA's David Geffen School of Medicine, who is one of the researchers involved, 'it may also influence the development of brain structures involved in language, providing a tangible link between genes, the brain and behavior.'"

Researchers know an increasing amount about brain cell communication - thank goodness. It is definitely key, writes this layperson. I like to read about neuroscience in a format I can understand, so I've read a tiny bit on neuronal activities. I don't really understand the electrical part that well, but I pretty much can wrap my mind around the chemical part.

"Although the mutated form could be inherited from either parent, children were about 20% more likely to develop autism if they inherited the gene from their mother."

Oh, oh, moms: you're not off the hook yet, if you have a mean-spirited, low-minded mother-in-law. Boo.

" 'We found a factor that is probably present in every autistic kid,' said geneticist Aravinda Chakravarti of the Johns Hopkins University School of Medicine, who led one of the studies. 'But while it may be necessary, it is not sufficient by itself to cause the disease.' "

Paraphrase: we have an idea as to the magnitude of the problem of studying autism, and we might have gotten a tiny key to unlock part of its solution.

©reated by Ribonuff on January 11, 2008 All Rights Reserved.