The presence of SPRED1 is particularly interesting given that deletions and point mutations in this gene are responsible for Legius syndrome, which is a genetic skin pigmentation disorder that is sometimes accompanied by other common manifestations, including moderate ID, ADHD, hypotelorism and pectus excavatum; these symptoms were present in the two patients with the 15q14q15.1 duplication. Here, SPRED1 is linked to attention deficit-hyperactivity disorder.