Diagnostic Utility of Hair Toxic Metals in Autism Spectrum Disorder: Unlocking Biomarkers Among Egyptian Children.

Researchers tested hair samples from 455 Egyptian children with autism and 230 children without autism to measure toxic metals. Children with autism had higher levels of aluminum, arsenic, cadmium, and lead in their hair. Aluminum levels were most useful for identifying autism risk and were linked to more severe autism symptoms. While these findings are interesting, hair metal testing should only be considered as part of a complete autism assessment, not as a standalone diagnostic tool.

This large Egyptian comparative study examined hair toxic metal levels in 455 children with clinically confirmed ASD versus 230 typically developing controls across eight governorates. Using inductively coupled plasma mass spectrometry, researchers found significantly elevated hair levels of aluminum, arsenic, cadmium, and lead in children with ASD, while mercury levels showed non-significant elevation. Aluminum demonstrated the strongest diagnostic performance with 89.4% sensitivity at a cutoff of ≥10.35 ppm and was the only metal positively correlated with ASD severity scores. The study established population-specific cutoff values for all five metals and suggests hair-based toxic metal profiling, particularly aluminum, may support early ASD risk detection when integrated within comprehensive diagnostic frameworks.

Hair toxic metal profiling may serve as a supportive tool in ASD risk assessment when combined with standard diagnostic procedures. However, it should not replace clinical judgment or established diagnostic criteria. Further validation across diverse populations and longitudinal studies are needed before clinical implementation.

Single-population study from Egypt limits generalizability. Study design not clearly specified. No information on potential confounding factors like diet, environment, or medication use. Causation versus correlation cannot be established. Long-term follow-up data not available.

This study aimed to assess the diagnostic utility of hair-based toxic metal profiling in Egyptian children with autism spectrum disorder (ASD). The objectives included establishing population-specific cutoff values for selected metals and examining their correlation with ASD symptom and severity. A national, facility-based comparative study was conducted across eight Egyptian governorates. It included 455 children with clinically confirmed ASD and 230 age- and sex-matched typically developing relatives.

ASD diagnoses were established using DSM-5 criteria and the Gilliam Autism Rating Scale, Second Edition (GARS-2). Hair samples were collected and analyzed for five toxic metals; aluminum (Al), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) using inductively coupled plasma mass spectrometry (ICP-MS). Receiver operating characteristic (ROC) curve analysis was applied to determine optimal diagnostic cutoffs. Sensitivity, specificity, and predictive values were calculated.

Correlation analyses were conducted to evaluate the association between metal levels and ASD severity. Children with ASD had significantly elevated hair levels of Al, As, Cd, and Pb compared to typically developing controls. Hg levels were statistically insignificant higher in the ASD group. Al showed the strongest diagnostic performance with 89.4% sensitivity and a cutoff ≥ 10.35 ppm.

Proposed cutoff values for the other metals were: As ≥ 0.10 ppm, Cd ≥ 0.10 ppm, Hg ≥ 0.31 ppm, and Pb ≥ 1.87 ppm. Only Al levels were positively correlated with ASD severity. Hair-based toxic metal profiling, particularly of Al, may support early ASD risk detection. However, it should be integrated within a broader diagnostic framework that includes clinical, behavioral, and environmental assessments.