Could a baby of 18 months with high levels of lead in her system be the cause of a diagnosis at age 6 of autisum spectrum disorder.

Autism spectrum: High lead levels at age six may be more responsible for brain damage.

No: There is no relation between the two. Strong genetic influence has been suspected.

Can contribute: But depends on length of time of exposure. If significant it can certainly compound symptoms formation. Definitely, the goal is to stop exposure to lead asap and to ensure this by ongoing blood work at least once per year. But it is not the only factor. Other big one is genetics. And Medical work up is key: genetics testing, hearing/vision testing, eeg (you listed) to check for seizures.