Abstract: Objective Analysis of 22 kinds of organic acid metabolites in myasthenia gravis, mitochondrial myopathy and healthy urine was performed so to provide data and basis for clinical screening. Methods The principal component and the corresponding principal component equation were obtained, and the physical and chemical significance of the principal component was explained. Results The cumulative contribution rate of the first five principal components reached 86.89%, was identified as the main component, then established the principal component function expression, and analyzed the relationship between the principal component and the original variable. It was found that the phenyl saturated acid might be a potential biomarker of the two diseases, and the hippuric acid was an early warning component of the two diseases.Conclusion Urine organic acid metabolic profile principal component analysis is helpful to find biomarker of disease and could assisted clinical diagnosis on the scientific basis.

Key words: Principal component analysis 1, Mitochondrial myopathy 2, Myasthenia gravis 3, Urine organic acid metabolic profile 4