Asperger syndrome is part of the autism spectrum disorder (ASD), a group of disorders that affects the development of social and communication skills. Unlike many children with ASD, children with Asperger syndrome do not have early language delays, and often have well developed language skills and normal to above average intelligence. However, they may use unusual speech patterns and have a hard time understanding irony, humor, and sarcasm or gestures and social cues important to normal conversation. Many children with Asperger syndrome develop an obsessive interest in one topic or object. They may use high-level vocabulary or complex statistics in conversation. Children with Asperger syndrome may have delayed motor skills and thus can appear uncoordinated and clumsy compared to their peers. Other features of Asperger syndrome include difficulty interacting with peers, inappropriate social or emotional behavior, and engaging in repetitive routines. Both children and adults with Asperger syndrome are at an increased risk for depression, attention deficit hyperactivity disorder (ADHD), mood and anxiety disorders, and other mental health disorders. The cause of Asperger syndrome, like most ASDs, is not fully understood, but there is a strong genetic basis, which means it does tend to run in families. Multiple environmental factors are also thought to play an important role in the development of all ASDs. Many people with Asperger syndrome can learn strategies to manage their symptoms.