Affiliations: Department of Biochemistry, Science College, King Saud
University, Riyadh, Saudi Arabia | Department of Medicinal Chemistry, National Research
Centre, Giza, Egypt | Department of Research on Children with Special Needs,
National Research Centre, Giza, Egypt | Department of Physiology, Faculty of Medicine, King
Saud University, Riyadh, Saudi Arabia
Note: [] Correspondence: Dr. Nagwa A. Meguid, National Research Centre,
Tahrir St., Dokki, Cairo, Egypt. Tel.: +20 1223316372; Fax: +20 237601877;
E-mail: meguidna@yahoo.com
Abstract: Autism spectrum disorders are complex developmental disorders with
increasing incidence and poorly understood etiology. Imbalance of amino acids
profoundly influences brain function, and is thought to be one of the key
players in the pathophysiology of autism. This study aimed to measure the
plasma amino acid profiles of 20 Egyptian and 20 Saudi autistic patients in
comparison to matching healthy controls to clarify the role of impaired amino
acid concentrations in the etiology of autism. Plasma amino acids profiles were
measured using high performance liquid chromatography. While plasma levels of
glutamic, aspartic, and glycine recorded the most significant percentage
elevated amino acids, glutamine, asparagine, arginine, tyrosine and isoleucine
recorded the most remarkable percentage decrease in autistic patients from both
populations compared to controls. Among the calculated relative values, only
acidic/basic, and glutamate/glutamine ratios were significantly higher in
autistics compared to controls. Non-essential/essential and
glucogenic/ketogenic ratios were unaltered in autistics compared to controls.
Increased plasma glutamate/glutamine ratio, together with increased glycine,
arginine, aspartate, aspargine levels, and acidic/basic amino acid ratio can
serve as a predictive tools for the early detection of autism. These findings
suggest that glutamatergic abnormalities in the brain may be associated with
the pathobiology of autism.
