Plasma amino acid profile in autism spectrum disorder (ASD).

OBJECTIVE: In our study, we aimed to reveal pathophysiologic mechanisms in ASD by comparing plasma amino acid levels between patients and healthy controls while considering vitamin B12 and D levels. PATIENTS AND METHODS: The study included 21 patients aged 2-18 years-old who were followed with a diagnosis autism spectrum disorder (ASD) and 21 age and sex-matched healthy children from our outpatient clinic as control group. RESULTS: The study included 42 children and adolescents aged 2-18 years-old (19 girls and 23 boys). There were no significant differences in terms of body weight and height between the groups. We found significant differences in levels of ammonium, phosphoethanolamine, histidine, homocysteine, carnosine, methionine, cystathionine, cystine, threonine, 3-methyl histidine and phenylalanine/tyrosine ratio between patient and control groups. Both vitamin B12 and D were significantly lower in the ASD group compared to controls. In the variance analysis with vitamin B12 and D as covariates, significant differences persisted for only phosphoethanolamine (p=0.04), cystathionine (p<0.001), cystine (p=0.006) and threonine (p=0.02). CONCLUSIONS: Further studies are needed on the amino acids that show variations in children with ASD in order to reveal their role in the etiology and therapeutic use in ASD.