ABSTRACT
The aetiology of autism is unclear and autistic symptoms had been attributed to an abnormal functional imbalance in neurotransmitter amines such as dopamine, noradrenaline and serotonin. To study plasma essential and non-essential amino acid levels, protein electrophoresis, serum ammonia, and urea in autistic children in comparison with controls. Twenty autistic children were compared to twenty healthy age and sex matched normal children serving as control, where serum amino acids, urea, ammonia and protein electrophoresis were estimated. As regards essential amino acid levels, autistic children had significant lower plasma levels of leucine, isoleucine, phenylalanine, methionine and cystine than controls [P < 0.05],while there was no statistical difference in the level of tryptophan, valine, threonine, arginine, lysine and histidine [P > 0.05]. In non-essential amino acid levels, phosphoserine was significantly raised in autistic children than in controls [.P < 0.05]. Autistic children had lower level of hydroxyproline, serine and tyrosine than controls [P < 0.05]. On the other hand there was no significant difference in levels of taurin, asparagine, alanine, citrulline, GABA, glycine, glutamic acid, and ornithine [P > 0.05]. There was no significant difference between cases and controls as regards the levels of urea, ammonia, total proteins, albumin and globulins [alpha 1, alpha 2, beta and gamma] [P > 0.05]. Autistic children had lower levels of some plasma amino acids except for glycine and glutamic acids and phosphoserine were increased with normal serum levels of urea, ammonia, total proteins, albumin and globulins [alpha 1, alpha 2, beta and gamma]