Abstract: The present disclosure relates to methods and kits for the diagnosis and treatment of autism spectrum disorder (ASD) in human subjects. The disclosure also relates to computer-implemented methods for diagnosing and treating ASD. Current diagnostic protocols are mainly limited to behavioural examination as laboratory findings have been consistently abnormal in ASD. No currently reported biomarker holds promise as early developmental screen or an early diagnostic or prognostic tool for pediatric settings at young ages from birth through early childhood when these clinical tools are most needed. With the present disclosure, metabolomic profiles, protein profiles and combinations thereof for ASD are identified in the subject having ASD.