The urinary biopterin in autism spectrum disorder

Abstract Objective The aim of the study was to determine whether biopterin is present in significantly lower quantities in urine samples of patients with autism spectrum disorder (ASD) compared to healthy individuals. Methods The concentration of biopterin in urine samples was measured by ELISA using commercially available kit. The study involved 53 children aged 3–16 years with ASD and 60 healthy children aged 2–14 years. Results Significantly lower biopterin concentration was observed in autistic patients compared to the control group. However, no significant difference was observed between mild, moderate, and severe ASD. Conclusion One of the potential causes of decrease in urinary biopterin levels may be tetrahydrobiopterin (BH4) deficiency, which has extensive and serious health consequences for the nervous system. The results of measuring biopterin as a fully oxidized form of BH4 may suggest that biosynthesis or regeneration of BH4 may be decreased in children with ASD. On the other hand, decreased urinary biopterin levels in children with ASD may be due to BH4 overuse, a good regeneration process, and decreased urinary excretion; and abnormalities in BH4 metabolism appear to be related to the aetiology of ASD or may be due to ASD.