Asperger syndrome (AS), also known as Asperger’s, is a neurodevelopmental disorder characterized by significant difficulties in social interaction and nonverbal communication, along with restricted and repetitive patterns of behavior and interests.[6] It is an autism spectrum disorder (ASD),[11] but differs from other ASDs by relatively unimpaired language and intelligence.[12] Although not required for diagnosis, physical clumsiness and unusual use of language are common.[13][14] Signs usually begin before two years of age and in many cases never resolve.[6]