Characterization of Factors Associated With Death in Deceased Patients With Mitochondrial Disorders

BACKGROUND AND OBJECTIVES: Mitochondrial disorders are multiorgan disorders resulting in significant morbidity and mortality. We aimed to characterize death-associated factors in an international cohort of deceased individuals with mitochondrial disorders. METHODS: This cross-sectional multicenter observational study used data provided by 26 mitochondrial disease centers from 8 countries from January 2022 to March 2023. Individuals with genetically confirmed mitochondrial disorders were included, along with patients with clinically or genetically diagnosed Leigh syndrome. Collected data included demographic and genetic diagnosis variables, clinical phenotype, involvement of organs and systems, conditions leading to death, and supportive care. We defined pediatric and adult groups based on age at death before or after 18 years, respectively. We used Kruskal-Wallis with post hoc Dunn test with Bonferroni correction and Fisher exact test for comparisons, Spearman rank test for correlations, and multiple linear regression for multivariable analysis. On multivariate analysis, individuals with movement disorders and nuclear gene involvement had increased odds of any respiratory support use (OR 2.42 (95% CI 1.17-5.22) and OR 2.39 (95% CI 1.16-5.07), respectively). DISCUSSION: This international collaboration highlights the importance of respiratory care and infection management and provides a reference for prognostication across different mitochondrial disorders.