27 genes

27.

That's how many genes might be "associated with either Asperger Syndrome (AS) and/or autistic traits and/or empathy" according to a new study in the July 16th Autism Research. Led by Dr Bhismadev Chakrabarti and Professor Simon Baron-Cohen from the Autism Research Centre, researchers identified 68 genes because they were associated with:

(1) neural growth
(2) social behavior
(3) sex steroid hormones (e.g. testosterone and estrogen)---these were chosen because of the higher incident of Asperger's in males than in females and because of research by the ARC about fetal testosterone levels and autistic traits and empathy in typically developing children

As described in yesterday's Science Daily, the genes of 349 adults who had completed the Autism Spectrum Quotient (AQ) and the Empathy Quotient (EQ) were compared to those of 174 adults with a formal Asperger's diagnosis. The results:

The research found that single nucleotide polymorphisms (SNPs) in 27 out of the 68 genes were nominally associated with either AS and/or with autistic traits/empathy. 10 of these genes (such as CYP11B1) were involved with sex steroid function, providing support for the role of this class of genes in autism and autistic traits. 8 of these genes (such as NTRK1) were involved in neural growth, providing further support to the idea that autism and autistic traits could result from aberrant patterns of connectivity in the developing brain. The other 9 genes (such as OXTR) were involved in social behaviour, shedding light on the biology of social and emotional sensitivity.

A comment by Prof. Baron Cohen about why the study looked specifically at individuals with Asperger's Syndrome:

"We chose to look at the genetics of AS because all other genetic studies have focused on classic autism, which can include learning difficulties and language delay. AS is a more 'pure' condition because these other factors are absent."

Neural functioning, social behavior, and hormones (specifically testosterone) are being pinpointed as particularly characteristic of Asperger's and, perhaps, of being on the autism spectrum. It's quite apparent that there is something different--dysfunctional, if you will---about my son's neurology; it's quite an understatement to say that he struggles socially. (I'll refrain from going into testosterone; certainly it's been a topic around here as my son is an adolescent.) His limited language/communication and cognitive abilities make testing and evaluation always a bit more of a challenge for Charlie, and also make it harder to figure out if he's not (for instance) responding because he doesn't understand a question, or because he can't retrieve the words quickly enough to answer.

There also seems to be the whiff of a suggestion here that neural functioning, social behavior, and hormones have something in particular to do with the autism spectrum. This is of interest in light of the proposed revisions to the DSM regarding how autism is defined with regard to "severity."

27 genes found, at least 20 more questions to ask.