A Genetic Link to Autism Found? Sceptical.
Okay, I’m playing the sceptic very strongly here.
Vathara told me about an article on Science Daily on Friday that claimed that they’ve found a definite genetic link to autism that doesn’t involve Fragile-X (which is more linked to intellectual delay/disability than autism directly). According to the Science Daily article, and the abstract of the article it’s taken from, it involves a mutation in the CHD8 gene that results in GI tract issues, insomnia, macrocephaly (large heads and wide-set eyes), and being on the autism spectrum. Okay.
How did they discover this? They looked at over 6,000 kids on the spectrum, and found 15 displaying those characteristics. They interviewed those 15 kids. A genetic analysis determined that they all had the CHD8 mutation. They then disrupted the CHD8 gene in zebrafish and, lo and behold, the fish developed macrocephaly and GI tract issues.
Oh, but wait. There’s one thing that the Science Daily article and the abstract (which is all I can access) don’t say. Namely:
Where are the neurotypical control groups showing: A) macrocephaly; B) the same GI tract issues; C) the same sleep disturbance issues; D) the same GI tract issues and macrocephaly; E) the same GI tract and sleep disturbance issues; F) the same sleep disturbance issues and macrocephaly; and G) the same GI tract and sleep disturbance issues and macrocephaly?
Now, it’s quite possible that the researchers did look at those control groups (or at least control groups D, E, and G), and they just aren’t listed in the article or the abstract for some reason. If this is so, and any of my readers can access the full text of the article, please let me know.
If the researchers didn’t have those control groups, on the other hand… how can they possibly claim that the gene mutation is linked to autism? It’s quite possible that it’s linked to GI tract issues and macrocephaly, but has nothing to do with autism. Or at least has very little to do with autism. Certainly the zebrafish can’t tell if they’re autistic.
So… potential problem there. Does anyone have any answers?
(wry look) tagAught