Researchers Identify Most Common Causes of Death in Children with Mitochondrial Diseases

Researchers studied the risk factors for mortality in children with mitochondrial disease and determined that the main causes of death were sepsis, an infection of the blood, and pneumonia. The study emphasizes the importance of early diagnosis and careful monitoring of these young patients.

The paper, “Cause of Death in Children with Mitochondrial Diseases,” was published in the journal Pediatric Neurology.

Mitochondrial diseases can be many different conditions with an array of differing symptoms. They are caused by a defect in a cell’s organelle called the mitochondria, which produces the energy that keeps the body and its organs functioning.

These defects in mitochondrial function can occur in any organ, but tend to occur in organs that use a lot of energy, such as the brain, heart, liver, and skeletal muscles — muscles attached to the bones.

Researchers studied the records of 221 pediatric patients diagnosed with mitochondrial diseases and followed at the Gangnam Severance Hospital at Yonsei University College of Medicine in Seoul, South Korea, from January 2006 to January 2015.

The causes of death, number of deaths, gender, and measures of survival time, among other things, were investigated.

Of 221 children followed up in the study, 31 of them, or 14%, died. Most of the patients who died (23, or  75%) lived for three to nine years; five patients (16%) lived less than three years; and three patients (10%) lived more than nine years.

The causes of death in children under the age of 15 with mitochondrial diseases were mainly sepsis (17 patients, or 55%) and pneumonia (13 patients, or 42%).

The researchers noted that sepsis is not a major cause of death in adult patients with mitochondrial disease and so improving the immunity of younger patients may be key to reducing pediatric mortality.

“Our study has several limitations,” the researchers wrote. “First, the size of our study population was small, which may imply that the results are not sufficient for making generalized interpretations for each syndrome… Large-scale studies with long-term follow-up are warranted for a comprehensive assessment of mortality in mitochondrial diseases.”

“More substantial surveillance and preparation for intervention are needed for patients aged less than 6 years, who are at a higher risk of death because of their immature and often compromised immunity,” they added. “Special monitoring and magnetic resonance imaging of the brain are indicated during follow-up to identify patients with indicators of high risk such as multiple organ involvement.”