This brief description of an MRI study from Cambridge relates that two areas of the brain may affect sociability by affecting the value of social rewards to a person.
They found that the greater the concentration of tissue in the orbitofrontal cortex (the outer strip of the brain just above the eyes), and in the ventral striatum (a deep structure in the centre of the brain), the higher they tended to score on the social reward dependence measure.
Presumably some neurologists with access to a store of MRIs will think to do this comparison on an informal basis across a selection of ASD and NT patients to see if there are any differences that might correlate with the results of this study. Where does that lead?
One good thing about science is that it always brings something new to the table. As these various pieces of information work their way into the minds of researchers, someone will do a logical experiment, such as looking for known human genes (or, as always, related mouse genes) that affect the growth of these two structures, and compare them to genes implicated in various autism genetics studies and databases or add them to the list of possible targets to explore as new data are obtained. This constant upgrading of the number of things that one might want to check for is one overriding reason why I’m in favor of whole-genome sequencing being available for individuals, particularly when the tools encourage personal control over the data. Using gene chips to screen for any, even a vast number of, set of targets is necessarily limited, since testing for a new target requires a new chip and perhaps a new sample (or access to the old sample from storage). Add up those costs, and the problem takes on new dimensions. The alternative, running a BLAST (if I remember correctly) of some new interesting sequence from researchers against a database of my own DNA, is a trivial expense in terms of time, money, or computing power, and, almost as importantly, one that is becoming cheaper while storage and retrieval of physical samples is becoming more expensive.