Autism is characterized by a broad spectrum of clinical manifestations, including (a) qualitative impairments in reciprocal social interactions, (b) qualitative impairments in verbal and nonverbal communication, (c) restricted repetitive and stereotyped patterns of behavior, interests and activities and (d) onset prior to the age of 3 years [1]. In most cases, the etiology is unknown, and patients are diagnosed with idiopathic or non-syndromic autism [10, 43]. About 70% of individuals with idiopathic autism have essential autism, defined by the absence of physical abnormalities, but in 30%, complex autism with dysmorphic features such as microcephaly and/or a structural brain malformation is diagnosed [79]. In 5–10% of cases, autism is diagnosed in association with other disorders such as fragile X syndrome, Rett syndrome, Down syndrome, and tuberous sclerosis [94, 105]. Intellectual impairments, defined as intelligence quotient (IQ) scores less than 70, were reported in 44.6% of children diagnosed with autism [28]. Epilepsy is observed in up to 33% of individuals with autism [106].
