Genetic and early brain-development factors
Autism spectrum disorder does not have a single clear cause. Most research describes autism as multifactorial, meaning it develops through a combination of genetic influences and early brain-development factors. Research also supports biological and genetic contributions rather than a single external factor, and it links autism to differences in early nervous system development.
Why autism does not have one single cause
Autism is not explained by one universal cause or one autism gene. Instead, many genes may affect the person’s chance of developing ASD, and for some people, inherited genetic factors play a larger role, while for others, additional developmental or biological influences are involved. This helps explain why autism is described as a spectrum, because two people can share the same diagnosis but still have different strengths, challenges, and support needs.
