Measurement of arylesterase enzymatic activity and assessment of genetic polymorphisms located in the PON1 gene as a diagnostic tool in autism-spectrum disorders

The present invention concerns a method for detecting the presence of or predisposition to autism, an autism spectrum disorder, or an autism-associated disorder in a subject, the method comprising measuring an arylesterase enzymatic activity in a sample from the subject, optionally combined with the determination of alleles of PON1 polymorphisms.