Diagnosing Mitochondrial Disease

Reaching a mitochondrial disease diagnosis can be a harrowing odyssey. People often shuttle between doctors, struggling with mysterious symptoms, uncertainty, anxiety and misinformation for years before finally getting a satisfying explanation for what is going on. A recent study found that patients saw an average of eight different clinicians before finally being diagnosed with a mitochondrial disease.

Mitochondrial diseases are so difficult to diagnose not just because they are rare, but because their symptoms are varied and also typical of much more common conditions. There are dozens of unique mitochondrial diseases, from Barth syndrome, which mainly affects the heart, to Leber’s hereditary optic neuropathy (LHON), which affects the eyes. The symptoms can differ vastly among them, and even among individuals with the same diagnosis. It can also be challenging for patients to have their concerns taken seriously because symptoms like weakness, fatigue and pain are invisible to others.

And none of these symptoms are unique to mitochondrial disorders. Since mitochondrial disease usually affects at least three different organ systems throughout the body, it usually takes a savvy doctor who recognizes a complex pattern of ”red flags” before considering the possibility of mitochondrial disease. Unfortunately, that revelation rarely comes early in the diagnostic odyssey, as multiple, more common possibilities are considered and then ruled out as symptoms continue.

"Since mitochondrial disease usually affects at least three different organ systems throughout the body, it usually takes a savvy doctor who recognizes a complex pattern of 'red flags' before considering the possibility of mitochondrial disease."

Mitochondrial disease symptoms can be easily mistaken for conditions like chronic fatigue syndrome or multiple sclerosis. Because symptoms of mitochondrial disease can be non-specific and “invisible” to others, doctors may think their patient has a psychiatric disorder. In some cases, patients may receive treatments for diseases they don’t actually have – treatments that do nothing to help their symptoms and may even expose them to harmful side effects.

Getting to a diagnosis of mitochondrial disease often involves a combination of fairly routine neurological exams and bloodwork. There could be additional testing that includes brain scans (MRIs), neuromuscular tests (electromyography), muscle biopsies and genetic tests. DNA sequencing techniques are still evolving and may be expensive, but can help reduce the need for other tests in some patients.

The end of the diagnostic odyssey is the beginning of another journey: living life as a mitochondrial disease patient. For some, simply having a name for their disease can be a big relief. For others, the knowledge presents new emotional challenges because of the lack of effective treatments. But as awareness of mitochondrial diseases increases and new treatments emerge, the journey to and beyond diagnosis may become a little easier.

The Journey

About 40,000 people in the United States are thought to have a mitochondrial disorder. Meet one of them.

Read Brandy's Story

The Caregivers

More severe mitochondrial disorders usually appear earlier in life. Find out what it's like to care for a child who has been diagnosed.

Read Cristy's Story