Cause of Death in Children With Mitochondrial Diseases

Background We investigated the clinical characteristics that represent risk factors for death in pediatric patients with mitochondrial diseases. Methods The medical records of mitochondrial disease pediatric patients attended between 2006 and 2015 (n = 221) were reviewed for clinical characteristics, diagnosis, hospitalization, follow-up, survival, and cause of death. Results The global mortality rate in the cohort was 14% (average age at death, six years). By syndromic diagnosis, the mortality rates were as follows: Leigh syndrome, 17% (15 of 88); mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes, 50% (two of four); and nonspecific mitochondrial disease, 11% (14 of 129). Data regarding 31 patients (17 males) were included in the analysis of cause of death. The age at symptom onset, lead time to diagnosis, duration of illness, and duration of life were 1.8 ± 2.0, 1.7 ± 1.5, 4.3 ± 2.7, and 6.1 ± 2.9 years, respectively. The most common causes of death were sepsis, pneumonia, disseminated intravascular coagulation, and sudden unexpected death (55%, 42%, 29%, and 29%, respectively). Early death (age six years or younger) was associated with lesions in the thalamus, number of organs involved, and Leigh syndrome. Conclusions Careful monitoring of the medical condition and early intervention are key to improving survival in pediatric patients with mitochondrial disease.