Parental germline exposures hypothesis

Instead of direct in‑womb environmental effects, some researchers propose that toxic exposures acting on parents' germ cells (sperm or eggs) could raise autism risk in offspring—blurring the line between 'genetic' and 'environmental' causes because the mechanism is mutation or epigenetic change in gametes. This reframes research priorities toward measuring parental exposures, germline mutation rates, and paternal‑age effects rather than only prenatal exposures. — If valid, this hypothesis changes how public health evaluates environmental risks, designs studies, and communicates about causes of autism without reviving vaccine myths.