Study Design: Using the Seahorse Analyzer, investigators will develop profiles of mitochondrial function for individuals with ASD and known MD (ASD/MD) and individuals with ASD known not to have MD (ASD/NoMD). These two groups will serve as the two ends of the spectrum of mitochondrial function in children with ASD and will be compared to profiles from TD children. Investigators will then examine the profiles of mitochondrial function in a general population of individuals with ASD to determine how these individuals fall into this spectrum defined by the ASD/MD and ASD/NoMD groups, as well as DD and no ASD/MD. Glutathione redox metabolism will be measured in all participants. The relationship between mitochondrial function, redox metabolism and core ASD symptoms will be studied in the ASD groups with particular attention to whether ASD symptoms, language ability and adaptive behavior are directly related to mitochondrial function or indirectly related to mitochondrial function through its effect on redox metabolism.