Childhood neurodevelopmental disorders such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and intellectual disability (ID) typically are complex, heterogeneous, conditions that show considerable clinical overlap.1 There are both genetic and environmental contributions to their aetiology, which are not yet fully elucidated. However, immense progress has been made in our understanding of their genetic basis in the last two decades. This short review aims to synthesise the key findings in this regard, with a focus on some of the factors that are most relevant to clinical practice.. To read the full article, log in using your NHS OpenAthens details.