Autism spectrum disorder (ASD) is a complex disorder involving both genetic and environmental contributions to the risk. It appears that heritable genetic factors play a large role in liability at the population level. There are, however, some results that seem at odds with our understanding of ASD genetic risk. For example, there is a low correlation of parents and probands in autistic traits. This deviation could be due to ascertainment in research studies, or it could be due to a lack of fit of the model. Thus an important part of the ASD risk puzzle could be missing.
To form a complete picture of the architecture of genetic risk for ASD, we must understand better the relationship between genetic risk for ASD and autistic traits in the population. We propose to do so here by examining this relationship both in ASD families and in the general population.