Here’s a good article on the criticality of early autism screening and detection testing beginning as soon as 18-24 months, from an article from our friends at the Reno Gazette Journal. http://www.rgj.com/story/life/wellness/2017/11/28/experts-recommend-screening-autism-18-and-24-months/902123001/
The article references a 23 point test for early autism detection, the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up, (M-CHAT-R/F)TM by Diana L. Robins, Ph.D, Deborah Fein, Ph.D and Marianne Barton, Ph.D. Here is the link to the original PDF you can download. Now of course this test should be administered only by an authorized medical provider.