Genetics: Although not well-explained, Autism has been seen to have a genetic basis. More than one gene has been known to be concerned in the development of the condition, but no proof has been gathered as yet.
Further, children suffering from genetically determined diseases like Fragile X Syndrome, Rett Syndrome and Tuberous Sclerosis are more prone to being autistic as compared to other children.
Prenatal Infections: Infections like rubella and cytomegalovirus contagion occurring in the mother during pregnancy have been seen to have adverse effects on the foetus, including the development of autism.
Exposure to certain medications: Prenatal exposure to certain medicines like thalidomide, valproic acid and SSRI’s increase chances of the child developing autistic traits.
Perinatal conditions: Low birth weight and hypoxia (deficient oxygen) during birth have been seen to be associated with higher chances of children being autistic.
Post vaccination: It has been found studying many cases that post vaccination, the symptoms of Autism Spectrum Disorder can crop up.