Metabolic Processes in Adults and Adolescents With Autism Spectrum Disorder

The objective of this study is to gain preliminary information and knowledge on metabolic profile in ASD. The benefit of this study will be to expand our insight of the potential relationship in metabolic processes and neuropsychological functions in ASD. For example, based on the obtained data of the study we can determine whether there is a link between the tryptophan pathway and cognitive functions in autism. The project is based on a systematic and multidisciplinary approach using tracers for delineating the mechanism by which the metabolism of amino acids like TRP is involved in affective and cognitive functions in ASD. Using an innovative approach to the evaluation of amino acids has not been used in adults with ASD. In addition, the obtained data of the study holds promise to develop specific markers (metabolic and/or neuropsychological) for guiding the identification those individuals with increased risk of developing mood disturbances or cognitive impairment, and for predicting the therapeutic effect of a specific nutritional interventions in subjects with ASD.

This study investigates the metabolic profile of different amino acids and cognitive functions in adults and adolescents with ASD in comparison with age- and gender-matched healthy young adults. The study involves 1 screening visit of approximately 2 hours and 1 study day of 5 hours

The objective is to explore changes in amino acids (e.g. TRP pathway) in ASD and evaluate the function of TRP in neuropsychological functions by using the technique of stable isotope and our newly developed 'single pulse method' with multiple amino acid and keto-acid isotopes.

The aim of this study is to determine the underlying mechanism by which the metabolism of amino acids such as TRP are involved in mood and cognitive functions in ADS.

Eligibility Criteria:
Inclusion Criteria Healthy:

* Healthy male or female according to the investigator's or appointed staff's judgment
* Age 16 years or older
* Ability to walk, sit down and stand up independently
* Ability to lie in supine or elevated position for 4 hours
* Willingness and ability to comply with the protocol

Inclusion criteria subjects with Autism Spectrum Disorder (ASD):

* Healthy high functioning person diagnosed with autism spectrum disorder
* Age 16 years or older
* Ability to walk, sit down and stand up independently
* Ability to lie in supine or elevated position for 4 hours
* Willingness and ability to comply with the protocol

Exclusion Criteria:

* Any condition that may interfere with the definition 'healthy subject' according to the investigator's judgment (for healthy group)
* Failure to give informed consent
* Established diagnosis of Insulin Dependent Diabetes Mellitus
* Metabolic diseases, including hepatic or renal disorders
* Presence of acute illness or metabolically unstable chronic illness
* Presence of fever within the last 3 days
* Pre-planned surgery of procedures that would interfere with the conduct of the study
* Any other condition according to the PI or study physician that would interfere with proper conduct of the study / safety of the patient
* Current alcohol or drug abuse
* Use of protein or amino acid containing nutritional supplements within 5 days prior to the study days
* Use of long-term oral corticosteroids or short course of oral cortico-steroids 4 weeks preceding first test day
* Body Mass Index of \< 18.5 or ≥ 40 kg/m2
* Montreal Cognitive Assessment score of \< 20