Science Fair: Gene Markers
An occasional column about science news pertaining to autism
Compiled by Robert B. Waltz
Many of us on the spectrum are afflicted with prosopagnosia, or face blindness -- I, for one, find it easier to remember the Greek roots of that word (prosopon+a+gnosia, face-no-knowledge) than most people's faces. Now there is an explanation for why people with otherwise good memories have trouble with faces.
Commentary: This isn't an article about autism, of course, and it's possible that prosopagnosia in people with autism is somehow distinct. But odds are that the broken mechanisms are related somehow.
A new study of genes related to autism finds a number of new candidate genes and adds additional support to the hypothesis that some cases of autism are caused by so-called "de novo" mutations -- that is, genes that mutated in the gametes which produced the child and were not present in the parent. It also finds that it generally takes more such mutations to cause autism in females.
Commentary: The disclaimer here comes way down in the article: "The mutations we find are present in about 10% of individuals with autism." In other words, while this is a genuine cause of autism, it is a relatively minor one. And although the odds of a woman developing autism from these causes is less than those for a man, it does not explain the disproportionate rate of diagnosis, because it explains so few overall cases of autism. (In this context, it is worth remembering that autism is diagnosed based on symptoms, not on causes. So two people who have the same genes for autism, if they present slightly differently, may not get the same diagnosis. Since autism is defined mostly in terms of social behavior, and women are generally more social, the probability remains that many women who are "biologically" autistic are not clearly "symptomatically" autistic and go undiagnosed.)
And if you want more on the problem of autism and girls, here is a commentary from Slate.
Author bio: AuSM member Robert B. Waltz was diagnosed with autism in 2012. He earned his B.A. in physics and mathematics from Hamline University in 1985. He is the author of three books on folklore, the editor of the online folk music database The Traditional Ballad Index, and recently has been informally studying the biology of autism.