Consider Testing Hair
Research, clinincal and parental experience has shown that a large majority of children with ASD's are heavy metal toxic. This is thought to be due to a faulty detoxification system with a concomitant rise in exposure to toxins, particularly, Mercury in the form of Thimerosal, a preservative in some vaccines.
Obtaining an Elemental Hair Analysis through Doctors Data Laboratory in the USA will enable you to apply the Counting Rules and give you the probability of Mercury toxicity based on a diagnosis of Disordered Mineral Transport. (You can do this through a UK handling laboratory although it is cheaper to go direct)
This will provide you with safe, non-invasive, relatively cheap clues for direction in helping your child. Any Practitioner will find this information useful too.
It is suggested you do this at the very beginning of your journey, so the results reflect the base-line position.
The test costs between £40-£65 depending on who handles the test for you.
Full details of how and why to test hair, including details of how to interpret the results can be found in by clicking HERE.
Generation Rescue has great information on the issues of Mercury and Heavy Metal toxicity