Dear Editor,
I read with great interest the article titled “Plasma Levels of Alpha and Gamma Synucleins in Autism Spectrum Disorder: An Indicator of Severity” by Al-Mazizi and Al-Ayadhi [1]. The authors evaluated the association between plasma α-synuclein, plasma γ-synuclein, and clinical severity in children with autism spectrum disorder (ASD). They observed a significant decrease in plasma levels of α-synuclein and increase in plasma γ-synuclein in children with ASD, and these two biomarkers were significantly associated with the severity of ASD. I have queries regarding characteristics of the two biomarkers.
The authors expressed the unit of two biomarkers as picograms per milliliter, but the detection limit by ELISA kit should be mentioned correctly. According to the homepage of the EIAab Science Company (Wuhan, China), the range of the measurement by ELISA Kit for α-synuclein and γ-synuclein is 15.6–1,000 pg/mL and 0.78–50 ng/mL, respectively. I believe that nanograms per milliliter may be appropriate and suggest that the authors check and confirm the units.
Regarding distribution of these biomarkers, the authors may consider presenting the data as log-normal distribution for each indicator. This means that mean ± SD in Table 1 by Al-Mazizi and Al-Ayadhi [1] should be changed to median (range) or geometric mean (geometric SD). As the sample sizes are limited, the statistical procedure is very important for reaching a conclusion.
Conflict of Interest Statement
The author has no conflicts of interest to declare.
Funding Sources
The author received no financial support for the research, authorship, and publication of this letter.
References
- 1.Al-Mazidi S, Al-Ayadhi LY. Plasma levels of alpha and gamma synucleins in autism spectrum disorder: an indicator of severity. Med Princ Pract. 2021;30((2)):160–7. doi: 10.1159/000513935. [DOI] [PMC free article] [PubMed] [Google Scholar]