In autism, the genetic etiology is about 10%. In recent years, environmental factors have come to the forefront more. Genetic relationships are more commonly observed in syndromic conditions, meaning; autism is part of the overall picture, but other significant clinical findings and problems (such as developmental delay, mental deficiency, deficiencies in fine and gross motor skills, and epileptic seizures) are also present.

In genetic predisposition, the expression of genes; disorders in expression or genetic sequences; are characterized by mutations. In such cases, karyotyping, WES, or CES can be performed, and the genome is screened. In the event of a mutation being found, further examinations and procedures may be carried out to clarify the situation, that is, to distinguish whether it is a VUS or a true pathogenic change.

Environmental factors, genetic factors, and epigenetic changes are in mutual interaction with each other. For example, it has been found in many scientific studies and findings that environmental factors such as inflammation or microbiota composition disorders play a significant role in both the expression of genetic traits and the occurrence of epigenetic changes, thus completing the cycle.