Abstract
CONTEXT: Plasma acylcarnitines are biomarkers of β-oxidation and are useful in diagnosing several inborn errors of metabolism but have never been investigated systematically in patients with mitochondrial myopathy.
OBJECTIVE: We hypothesized that acylcarnitines can also be biomarkers of mitochondrial myopathy and sought to investigate the prevalence and pattern of elevated acylcarnitines.
DESIGN: This was a prospective cohort study of patients with confirmed mitochondrial myopathy followed at Copenhagen Neuromuscular Center, Rigshospitalet, Copenhagen, Denmark.
PATIENTS: We included 35 patients (44 ± 15 years, 15 women) with mitochondrial myopathy caused by single, large-scale deletions of mitochondrial DNA (n = 17), pathogenic variants in mitochondrial transfer RNA (n = 13), or in proteins of the respiratory chain complexes (n = 5).Concentrations of 35 acylcarnitines were measured using ultra-HPLC and tandem mass-spectrometry. Findings were compared with muscle mutation load in all patients and to respiratory chain activity in 26 patients.
MAIN OUTCOME MEASURES: Prevalence of elevated concentrations of acylcarnitines related to acyl-coenzyme A (CoA) dehydrogenases in patients with mitochondrial myopathy and relation to genotypes/phenotypes.
RESULTS: In total, 27 (77%) patients had elevated concentrations of acylcarnitines related to acyl-CoA dehydrogenases. Elevated concentrations of seven acylcarnitine species were more common in patients compared with a control cohort of >900 individuals, and a specific pattern involving hydroxylated long-chain acylcarnitines occurred in 22 (63%) patients. Severity of derangements was correlated with muscle mutation load and genotypes/phenotypes.
CONCLUSION: In conclusion, elevated concentrations of acylcarnitines is common in patients with mitochondrial myopathy and shows a specific pattern affecting hydroxylated long-chain acylcarnitines, which can have implications for future diagnostic workup of patients.
Original language | English |
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Journal | The Journal of clinical endocrinology and metabolism |
Volume | 104 |
Issue number | 12 |
Pages (from-to) | 5968-5976 |
Number of pages | 9 |
ISSN | 0021-972X |
DOIs | |
Publication status | Published - 1 Dec 2019 |