Abstract: Background: Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by altered metabolism, particularly in amino acid pathways.

Methods: A case-control study compared plasma amino acid profiles between 75 children with ASD and 75 typically developing controls. High-performance liquid chromatography-tandem mass spectrometry analyzed 20 standard amino acids.

Results: Significant elevations in glutamate (84.5 ± 12.3 vs 65.2 ± 10.8 μmol/L, p<0.001) and reductions in glutamine (445.2 ± 58.6 vs 512.4 ± 62.3 μmol/L, p<0.001) and tryptophan (42.3 ± 8.4 vs 52.6 ± 7.9 μmol/L, p<0.001) were observed in the ASD group. Strong correlations emerged between glutamate levels and ADOS-2 scores (r=0.62, p<0.001).

Conclusion: The study demonstrates distinct amino acid profiles in ASD, suggesting potential biochemical markers for diagnosis and monitoring. These findings may guide the development of metabolic screening tools and targeted therapeutic interventions.