Mitochondrial Disease an Enormous Burden on U.S. Patients, Study Finds

Mitochondrial disease is very costly to American patients and better therapies are needed urgently, say researchers at the Children’s Hospital of Philadelphia (CHOP).

Their National Institutes of Health-funded study, “Hospitalizations for mitochondrial disease across the lifespan in the U.S.,” appeared in the April 2017 issue of Molecular Genetics and Metabolism.

Mitochondria are tiny structures found in large numbers within cells. They work as cellular power plants, transforming nutrients in energy to fuel human bodies. They carry their own DNA and genetic profile, but when disease-causing mutations strike these genes, patients may suffer from a series of disorders called “mitochondrial diseases” that impair energy production in cells.

The CHOP study, which compared U.S. hospitalization costs using national databases, found that patients with mitochondrial disease pay way more for hospital treatment than most other patients. In addition, they suffer higher-than-normal rates of co-morbid diseases and in-hospital mortality because of how available treatments are administered — underscoring the urgent need for lower-risk, novel therapies.

“There have been few systematic investigations of the public health burden of mitochondrial disease, even as these disorders are being diagnosed more frequently than ever before,” Dr. Shana E. McCormack, study author and CHOP pediatric researcher, said in a press release. “We hope that our initial efforts to define the scope of this problem will lead to better medical practice in helping patients and families.”

Analyzing a national database from 2012, researchers studied the hospitalization records of 3,200 children and 2,000 adults. They found that estimated costs of a hospital visit were twice as high for patients with a mitochondrial disease as for patients without mitochondrial disease.

Researchers also found in-hospital mortality rates of 2.4 percent for children and 3.0 percent for adults with mitochondrial disease — about six times the average for kids and three times the average for adults in the general population. A separate analysis of California hospitals from 2007 to 2011 found that  mitochondrial disease patients with at least one hospitalization during that time had an average 1.1 hospitalizations yearly after that. Children under two years of age were hospitalized most frequently.

According to the CHOP study, mitochondrial disease occurs in one of 4,300 U.S. births — and actual costs and disease burden could well be higher than estimated, since hospital discharge records often fail to register mitochondrial disease.

“We hope that better knowledge of the economic burden of mitochondrial disease will lead to improved funding for research and drug development,” said Dr. Marni J. Falk, the study’s co-author and executive director of CHOP’s Mitochondrial Medicine Center. “In addition, understanding the true health burden may help healthcare providers and administrators to refocus efforts to prevent death and severe disability from mitochondrial disorders.”