Linshinski, Angela

ABSTRACT 3‐hydroxy acylcarnitines (3‐OH‐ACs) are key biomarkers for screening of long‐chain 3‐hydroxyacyl‐CoA dehydrogenase and trifunctional protein deficiencies (LCHADD/TFPD). The utility of this biomarker for disease monitoring in identified patients remains debated, and recent suggestions have highlighted the potential use of lipidomics for diagnosis, monitoring, prognosis, and/or identification of new biomarkers. We evaluated the use of omics in LCHADD/TFPD patients by analyzing plasma acylcarnitine profiles, metabolomics, and lipidomics, combined with genotype, visual assessments, and dietary records. Fasting plasma from 39 participants with LCHADD/TFPD and 32 control subjects were analyzed through untargeted metabolomic and lipidomic analyses. In LCHADD/TFPD participants, acylcarnitine profiling, visual and retinal function assessments were performed, and 3‐day diet records were collected. Relationships between acylcarnitines, metabolomics, lipidomics, along with visual outcomes and dietary intake were investigated. Plasma of LCHADD/TFPD participants exhibited elevated 3‐OH‐ACs, which correlated with genotype and visual outcomes. Metabolomics successfully distinguished LCHADD/TFPD from controls, and the biggest divergence was observed in lipid pathways. Metabolomic profiles tightly correlated with 3‐OH‐ACs, genotype, and visual outcomes. Lower concentrations of total lipids and some individual lipid species such as phosphoethanolamines (PE) were detected in LCHADD/TFPD, except for elevations in several certain triglycerides. LCHADD/TFPD participants followed a diet low in long‐chain fat (LCFA) as recommended. LCFA intake did not correlate with either plasma 3‐OH‐ACs or metabolomics. 3‐OH‐ACs are strong consistent biomarkers of LCHADD/TFPD that are associated with clinical parameters of vision and genotype. We did not observe a relationship between dietary LCFA intake and 3‐OH‐ACs.