Article Type

Original Study


Objective The aim of this study was to assess the plasma zinc (Zn)/serum copper (Cu) ratio as a biomarker in children with autism spectrum. Background Autism is a complex, behaviorally defined neurodevelopmental disorder characterized by significant impairments in social interaction, verbal and nonverbal communication, and restrictive, repetitive, and stereotypic patterns of behavior. The possible etiologies that precipitate autism symptoms remain controversial in many cases, but both genetic and environmental factors have been implicated. Children with autism spectrum disorder (ASD) appear to be at risk for Zn deficiency, Cu toxicity, and often have low Zn/Cu ratio. Patients and methods The present study was designed to be of a case–control type. It enrolled 40 children. Twenty patients with autism diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th ed., text revision and the Childhood Autism Rating Scales were included. The control group enrolled 20 apparently healthy children, matched to the patients' age and sex. All of them were subjected to biochemical analysis for assessment of plasma Zn level and serum Cu, followed by calculation of plasma Zn/serum Cu ratio. Results Plasma Zn was decreased in patients than in controls. Serum Cu was higher in patients than in controls. Lower Zn/Cu ratio was observed in cases in comparison with controls. intelligence quotient was lower in patients than in controls. There was a correlation between age and Zn/Cu ratio, but there was no correlation between Zn/Cu ratio and BMI. There was a negative correlation between Childhood Autism Rating Scales and Zn/Cu ratio. Zn/Cu correlated negatively with some selected symptom severity in autistic children and Zn/Cu ratio. According to receiver operating characteristic curve, the optimal cutoff value of serum levels of Zn/Cu was projected to be 0.81, with a sensitivity of 85% and a specificity of 85%, and the area under the curve was 0.93. Conclusion Our results suggested an association between blood levels of Zn and Cu with ASD among our patients, and the Zn/Cu ratio could be considered a biomarker of ASD.