The method used in this artical is BRAIN SCAN, not GENETIC SCREENING .
The genetic related to Autism was found already: "Some of the candidate genes of idiopathic autism (90-95% of all cases) related to brain metabolism are AVPR1a, DISC1, DYX1C1, ITGB3, SLC6A4, RELN, RPL10 and SHANK3."
And, as the artical posted in main post mentioned, knowing the corresponding genes which triggers Autism progessses locating the specfic areas of the brain related to Autism. Which will drastically improve accuracy.