Amino acids profiles of children who stutter compared to their fluent sibling

Purpose: This study scrutinises the abundances of 9 neurological-related amino acids of the scalp hair of 35 (5 females, 30 males) children who stutter and 30 normally fluent children (age and sex matched).Methods: Samples of hair from children who stutter aged (5-9 years) were collected from Speech Clinic at King Abdullah Hospital. The control subjects were selected from the same families of children who stutter to exclude the effect of nutritional, environmental, and biological factors. Amino Acid Analyser was used to measure the concentrations of amino acids in acid hydrolysed hair samples.Results: results indicated that the concentrations of threonine, tyrosine, and isoleucine (p = 0.001, 0.001, 0.02 respectively) are lower in hair samples of people who stutter compared with samples of normal fluent speakers.Conclusion: The findings of this study could introduce a new treatment protocol including the supplementation of reduced nutritional elements.KEY POINTSConcentrations of amino acids (threonine, isoleucine, and tyrosine) in the hair samples of people who stutter were significantly lower than the concentrations in the hair samples of control group.Concentrations of amino acids (histidine and glutamate) in hair samples of people who stutter were lower than control group with low significant values.The concentrations of amino acids (phenylalanine, serine, glycine, aspartate, glutamate) were not significantly different between hair samples of stuttering group and control group.The findings of the current study will be helpful in designing a new treatment method based on the supplementation of deficient amino acids.