Friday, July 18, 2008

Lessons from gene deletions affecting learning and autism both

On the one hand, this article annoyed me. It demonstrates the usual confusion between association and causation, and it extrapolates from an exotic genetic disorder to the much larger group of children labeled as "autistic".

The reasoning errors, incidentally are not the journalist's. They come from the researchers. Researchers are as prone to this fallacy as anyone else.

On the other hand, it has some interesting hints. So I'll delete the worst parts, and focus on the interesting hints.
Autism Genes That Control Early Learning: Scientific American

A new genetic analysis of large, inbred Middle Eastern families... pinpointed six new genes that may contribute to autism ....
They report in Science that all of the linked genes are involved in forming new and stronger connections, called synapses, between nerve cells in the brain, which is the biological basis of learning and memory formation...

The researchers studied 88 families in which one or more children had been diagnosed with autism, and the parents of each autistic child were cousins. Marrying second and third—and even first cousins—is not uncommon in the Middle East...s
The team found a total of six mutations affecting genes that had previously not been linked to autism. The mutations came in the form of deletions, where part or all of both copies of the genes were missing in a child with the disorder. All of the genes are known to be involved in parts of the same process: creating and strengthening synapses...
...Walsh says the team believes these deletions—which in most cases found here only remove some, but not all, of the DNA that makes up a gene—may mean that the genes can regain some of their normal function. In fact, some of these genes may just be switched off. "This presents the possibility that in some kids we could get the gene going again without necessarily having to put it back in the brain," he says...
...Walsh notes that many children diagnosed with autism tend to show vast improvement when they are placed in environments that allow them to practice learning repetitively. He says that these activities essentially train the neurons to make up for their lost function.
From a science perspective it's another advance in studying neurodiversity, and it fits in the context that large numbers of "normal" people have significant neuro gene deletions.

From a parent's perspective, I was struck by the idea that these neurons can form connections, but they take a lot of persistence to form. In particular, highly repetive learning.

It's hard to do that kind of teaching in a conventional classroom. It bores most students and teachers to tears. This fits with our experience in trying to teach reading however ...

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