Methylmalonic acidemia (MMA), propionic acidemia (PA), and cobalamin C deficiency (cblC) share a defect in propionic acid metabolism. In addition, cblC is also involved in the process of homocysteine remethylation. These three diseases produce various phenotypes and complex downstream metabolic effects. In this study, we used an untargeted metabolomics approach to investigate the biochemical differences and the possible connections among the pathophysiology of each disease. The significantly changed metabolites in the untargeted urine metabolomic profiles of 21 patients (seven MMA, seven PA, seven cblC) were identified through statistical analysis (p < 0.05; log2FC > |1|) and then used for annotation. Annotated features were associated with different metabolic pathways potentially involved in the disease’s development. Comparative statistics showed markedly different metabolomic profiles between MMA, PA, and cblC, highlighting the characteristic species for each disease. The most affected pathways were related to the metabolism of organic acids (all diseases), amino acids (all diseases), and glycine and its conjugates (in PA); the transsulfuration pathway; oxidative processes; and neurosteroid hormones (in cblC). The untargeted metabolomics study highlighted the presence of significant differences between the three diseases, pointing to the most relevant contrast in the cblC profile compared to MMA and PA. Some new biomarkers were proposed for PA, while novel data regarding the alterations of steroid hormone profiles and biomarkers of oxidative stress were obtained for cblC disease. The elevation of neurosteroids in cblC may indicate a potential connection with the development of ocular and neuronal deterioration.

A variant of the analysis of biological tissue (standard liver specimen, NCSZC 85005 Beef liver), where its reference specimen is q standard specimen of the geological matrix (soil, IAEA Soil-7), is...

A significant number of inherited neurodegenerative metabolic diseases (NMD) arise from altered lipid metabolism, including impaired degradation of sphingolipids and dysfunction in organelle-related machineries involved in lipid processing and trafficking. These lipid dysregulations profoundly impact cellular membranes, signaling pathways, and myelin integrity, contributing to the complex and multisystemic clinical phenotypes characteristic of NMD, which often complicate diagnosis and delay treatment initiation. Here, we present a high-throughput, multiplex liquid chromatography-mass spectrometry (LC-MS/MS) method for the analysis of an extended panel of NMD biomarkers in plasma and dried blood spots. One-step sample extraction and targeted LC-MS/MS acquisitions in positive and negative ionization allowed the simultaneous meausurement of 13 diagnostic biomarkers associated with GM1 and GM2 gangliosidosis, Fabry, Gaucher, and Krabbe diseases, acid sphingomyelinase deficiency (ASMD), Niemann-Pick disease type C (NPC), X-linked adrenoleukodystrophy (X-ALD), peroxisomal biogenesis disorders (PBD, Zellweger syndrome), metachromatic leukodystrophy (MLD), and MEDNIK/MEDNIK-like syndromes, a disorder of cellular trafficking. The method was analytically and clinically validated, confirming the diagnosis of all targeted NMDs in samples from 89 patients. Additionally, the method allowed the differentiation of X-ALD from PBD and revealed the elevation of C18- and C16-sulfatides in Krabbe-disease and MEDNIK-syndromes, respectively. This multiplex assay enhances diagnostic efficiency and expands the discovery of novel biomarkers, enabling the quantification of diagnostic markers for a wide range of NMDs. The method is suitable for diagnosis of NMD, as a first- or second-tier test in neonatal screening, as confirmatory testing of variant of unknown significance in genetic panels and for longitudinal monitoring in treatable diseases.

Methylmalonic acidemia (MMA), propionic acidemia (PA), and cobalamin C deficiency (cblC) share a defect in propionic acid metabolism. In addition, cblC is also involved in the process of homocysteine remethylation. These three diseases produce various phenotypes and complex downstream metabolic effects. In this study we used an untargeted metabolomics approach to investigate the biochemical differences and the possible connections with the pathophysiology of each disease. Untargeted urine metabolomic profiles of 21 patients (7 MMA, 7 PA, 7 cblC) were identified through statistical analysis (p|1|) and then used for the annotation. Annotated features were associated with different metabolic pathways potentially involved in the diseases development. Comparative statistic showed markedly different metabolomic profiles between MMA, PA and cblC, highlighting characteristic species for each disease. The most affected pathways were related to the metabolism of organic acids (MMA, PA, cblC), amino acids (MMA, PA, cblC), glycine and its conjugates (PA), transsulfuration pathway (cblC), oxidative processes (cblC) and neurosteroid hormones (cblC). The untargeted metabolomics study highlighted the presence of significant differences between the three diseases, pointing to the most relevant contrast of cblC profile compared to MMA and PA. Some new biomarkers are proposed for PA, while novel data regarding the alterations of steroid hormone profiles and biomarkers of oxidative stress were obtained for cblC disease. The elevation of neurosteroids in cblC may indicate a potential connection with the development of ocular and neuronal deterioration.