Plasma Amino Acid Profile in Children with Autism Spectrum Disorder in Southern China: Analysis of 110 Cases

To retrospectively explore the characteristics of plasma amino acids (PAAs) in children with autism spectrum disorder and their clinical association via case-control study. A total of 110 autistic and 55 healthy children were recruited from 2014 to 2018. The clinical phenotypes included severity of autism, cognition, adaptability, and regression. Compared with the control group, autistic children had significantly elevated glutamate, gamma-Amino-n-butyric acid, glutamine, sarcosine, delta-aminolevulinic acid, glycine and citrulline. In contrast, their plasma level of ethanolamine, phenylalanine, tryptophan, homocysteine, pyroglutamic acid, hydroxyproline, ornithine, histidine, lysine, and glutathione were significantly lower. Elevated neuroactive amino acids (glutamate) and decreased essential amino acids were mostly distinct characteristics of PAAs of autistic children. Increased level of tryptophan might be associated with severity of autism.

Automated summary

This case-control study retrospectively explored the characteristics of plasma amino acids (PAAs) in children with autism spectrum disorder and their clinical association. Compared to the control group, autistic children exhibited elevated levels of glutamate, gamma-Amino-n-butyric acid, glutamine, sarcosine, delta-aminolevulinic acid, glycine, and citrulline, while plasma levels of ethanolamine, phenylalanine, tryptophan, homocysteine, pyroglutamic acid, hydroxyproline, ornithine, histidine, lysine, and glutathione were significantly lower. The increased neuroactive amino acids and decreased essential amino acids were distinct characteristics of PAAs in autistic children, and the elevated level of tryptophan may be associated with autism severity.