It has become apparent that genetic structural variation contributes significantly to both neurocognitive and neuropsychiatric disease. Evan Eichler presents a detailed study of the genomes of children with developmental delay compared to adult controls and shows that as much as 14% of pediatric disease, including autism, epilepsy and intellectual disability, is caused by deletions and duplications of large segments of the genome involving multiple genes. These mutations can be either inherited or found in the parents of children depending on the size of the event. (#24426)