Analysis of urinary 8-hydroxy-2-deoxyguanosine as a biomarker of oxidative DNA damage in pediatric children with autism spectrum disorder

Background: Autism spectrum disorder (ASD) is a neurodevelopmental condition that manifests itself in infancy. While genetic factors are the most important in its development, numerous other variables, as neurological, environmental, and immunological factors, have been found. The imbalance of oxidants and antioxidants has a role in the pathogenesis of ASD. We evaluated children with autism for the presence of oxidative DNA damage (ODD) biomarker 8-hydroxy-2-deoxyguanosine (8OHdG) and assessed its association with disease severity, and omega supplementation. Methods: A total of 102 children (51 children with ASD and 51 typically developed children) were recruited for this observational controlled cross-sectional study. Childhood Autism Rating Scale (CARS) was used to measure the severity of autism. The urinary 8-OH-dG was determined using the ELISA method.Results: urinary 8-OH-dG/creatinine levels were significantly higher in children with autism compared to their healthy peers (P < 0.001) with positive significant association with disease duration, severity, and positive family history (P = 0.03, P < 0.001, P = 0.03 respectively). Using a cut-of value of > 1.7, urinary 8-OHdG/creatinine ratios showed sensitivity and specificity 80.39% and 74.51% respectively as a good discriminating power between normal and autistic children. Additionally, statistically lower significant urinary 8-OHdG/creatinine was found among ASD children received omega 3 than those who didn't receive it (p < 0.001).Conclusion: Increased urinary 8-OHdG/creatinine levels indicate an important role of oxidative DNA damage in ASD, and its significant higher level in ASD children with severe social impair-ment may be used as a potential non-invasive biomarker for disease severity.