While currently there is no known single cause for ASD, it is generally accepted that ASD is biological and affect brain development. In some cases, specific genetic syndromes, such as Rett’s Syndrome, Fragile X and tuberous sclerosis, result in symptoms of ASD. Other genetic causes, such as small copying errors in the genetic code, have recently been identified and research is investigating environmental factors that may be linked to ASD. In general, there appears to be different types of ASD which may be associated with many different causes.
