Commentary: We've only just begun: unravelling the underlying genetics of neurodevelopmental disorders - a commentary on Kiser et al. (2015)

Kiser and colleagues (this issue) have presented us with a comprehensive and bold review that describes current understanding of the genetic influences that underpin three of the most important neurodevelopmental disorders: attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and intellectual disability (ID), and explores several new avenues of thinking that are opening up based on this knowledge. Based on phenotypic overlap, comorbidity and a sharing of genetic and environmental risks they propose that ADHD, ASD and ID together form part of a continuum. The idea that disorders we have traditionally seen as being separate are in fact inter-related is, of course, not an entirely new one and indeed has similarly been proposed for the developmental disorders by Gillberg and in a more general way as a part of the NIMH Research Domain Criteria (RDoC) project. Where this review differs is in the authors' attempts to look at several possible mechanisms for these.