RIT1 and attention deficit-hyperactivity disorder: In addition to manifestations listed above, NS patients may experience short stature, autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD)10–13, gastrointestinal problems14, etc. The genetic etiology of NS is heterogeneous and most commonly results from mutations in PTPN11, SOS1, KRAS, and RIT1 genes9.