what can cause autism

Autism is caused by a combination of multiple genetic and environmental factors, rather than a single cause. Genetic influences include both rare gene mutations and common genetic variations that together can increase the likelihood of autism. Environmental factors linked to autism risk include advanced parental age, prenatal exposure to air pollution or certain pesticides, maternal obesity, diabetes or immune system disorders, birth complications, and exposure to some toxic chemicals. Interaction between these genetic and environmental factors further affects the probability of a diagnosis. There is no evidence that vaccines cause autism. Autism is a complex neurodevelopmental disorder with contributions from genetics, prenatal environment, and possibly epigenetic mechanisms. Some maternal infections, autoimmune issues, or oxidative stress during pregnancy may also play roles. The understanding of autism causes is incomplete and likely involves many factors acting together.