Plasma Acylcarnitine and Urinary Organic Acid Profiling for the diagnosis of Fatty Acid Oxidation Disorder and Organic Acidurias using tandem mass spectrometry (MS/MS) and gas chromatography tandem with mass spectrometry (GC-MS): A Retrospective Study

Abstract

Introduction: Plasma acylcarnitines (PLAC) and urinary organic acids (UOA) are essential diagnostic markers for some Inborn Errors of Metabolism (IEM) such as fatty acid oxidation disorders (FAODs) and disorders related to organic acids metabolism.

Objective: This study aimed to establish the PLAC and UOA profiles of Filipino newborn babies at risk for IEMs using FIA-MS/MS and GC-MS. Further, this study describes the process of determining the true positive cases of FAODs and some organic acidurias.

Methodology: PLAC and UOA analyses were performed using Waters® MS/MS and Agilent® GC-MS. Results were obtained from databases and IEM registry of the Biochemical Genetics Laboratory from 2015 to 2021. Descriptive statistics was used to evaluate the detection rates of FAODs and Organic Acidurias.

Results:Data from 2015-2021, indicated 176 true positives out of 1642 babies screened at risk for FAODs and organic acidurias. The use of MS/MS and GC-MS yielded a detection rate of 10.6% with 104 Filipino newborn babies with FAODs while 72 with organic acidurias. Medium-chain acyl-CoA dehydrogenase deficiency was reported to be the most common FAOD with 67 cases. Organic acidurias such as glutaric aciduria type 1 and 3-

Conclusion: The PLAC and UOA profiles of Filipino newborn babies with FAODs and organic acidurias were presented in this paper. This study emphasizes the importance of conducting confirmatory testing to establish the true positive cases. Thus, this study warrants further studies on the validation of analytical methodologies for targeted measurements of biomarkers of IEMs. Methylcrotonyl-CoA carboxylase deficiency were found to be common with 34 and 26 cases, respectively.