ABSTRACT
The pathophysiology and genetics of communication disorders (e.g. stuttering), developmental disorders (e.g. autism spectrum disorders) and intellectual disabilities (e.g. phenylketonuria, Tay-Sachs disease and fetal alcohol syndrome) are discussed. The different disorders on the autism spectrum disorder continuum (e.g. Joubert syndrome, Asperger syndrome, progressive developmental disorder, childhood disintegrative disorder and Rett syndrome) are explained. Savant syndrome and savants are defined and discussed, both as a feature seen in some autism sufferers and as a separate phenomenon. Tic disorders such as Tourette syndrome are discussed in terms of pathophysiology and genetics. Environmental factors that may contribute to the cause of these disorders are considered.
