A study was published on March 10, 2015 about the relationship between genetic risk factors for autism spectrum disorder (ASD) and intelligence. This reflects the impression that some people with ASD may have areas of superior intelligence (the so-called “Silicon Valley Syndrome”).
In this study, polygenic risk for ASD (and also for attention-deficit hyperactivity disorder – but this is not being summarized in this article) was calculated from genome-wide association studies of ASD that were conducted by the Psychiatric Genetics Consortium. In a cohort of 9863 people, the polygenic risk for ASD was positively correlated with general cognitive ability (i.e. intellectual ability was higher). The specific areas in which individuals with polygenic risk for ASD were superior were logical memory, vocabulary, and verbal fluency. This was replicated by these researchers in another cohort of 1522 people, in whom individuals with polygenic risk for ASD had higher full-range intelligent quotient (IQ).
These results, however, do not show that the genes for ASD create geniuses. The differences in cognitive scores between the individuals at polygenic risk for ASD and those who did not have this risk was small. The genetic risk scores explained less than one half of a percentage (0.5%) of the variation in the scores on cognitive tests.
This study also does not address the question of intellectual ability of people with ASD. Instead, it shows that the same genetic milieu that is associated with ASD is also associated with higher cognitive scores.
This study can easily be over-interpreted. But it may be taken to show that ASD, for some individuals and their families, can be a gift as well as a challenge.
Clarke T-K, Lupton MK, Fernandez-Pujals AM, et al. Common polygenic risk for autism spectrum disorder (ASD) is associated with cognitive ability in the general population. Molec Psychiatry 2015 March 10;epub ahead of print.