Mitochondrial Myopathy

Mitochondrial myopathy is a neuromuscular disease that affects the cell's mitochondria. Mitochondrial diseases are relatively common. However, they are often misdiagnosed or undiagnosed, due to a lack of epidemiological studies, which makes getting accurate statistics difficult. Mitochondrial myopathy does not have a bias; it will affect everyone. It does not care about sexuality, someone's personal identification, religion, or ethnicity. It will affect everyone. Yes, that means you, too, Karen.

Mitochondrial myopathy is caused by a genetic mutation that affects the production of ATP in the mitochondria. According to the Children's Hospital of Philidelphia, "Mutations in this mtDNA or mutations in nuclear DNA (DNA found in the nucleus of a cell) can cause mitochondrial disorder. Environmental toxins can also trigger mitochondrial disease." A cell that has defective mitochondria throws the whole cell’s function off-kilter. It can cause a backlog of molecules that are used for fuel, along with a destructive form of oxygen called free radicals, as well as reactive oxygen species. These rogue oxygen molecules attack antioxidants that help fight off disease and aging. The mitochondria can also create excess lactic acid that causes muscle fatigue, and in some cases, damage to the muscles.

How is mitochondrial myopathy diagnosed? Well, a muscle biopsy is used to help aid the diagnosis. For those who don't know, a muscle biopsy is a minor surgery that takes a small sample of muscle and sends it off for testing. A muscle biopsy helps with testing a multitude of different bodily aspects such as electron microscopy (looking at the electrons in the muscles), respiratory chain enzymology (looking at ATP production), and histopathology (the changes in tissue due to disease). A muscle biopsy is truly pivotal to diagnosing mitochondrial myopathy. According to the BC Medical Journal, “diagnosis is complex and requires the integration of information obtained by history, laboratory testing, imaging, and muscle biopsy.” A test done to diagnose mitochondrial myopathy is blood and urine testing. In these tests, doctors look for abnormal levels of lactates. Lactate levels are commonly more prominent in individuals who have a more severe case of mitochondrial myopathy, though, this test is not always effective. Another test done is Electromyography (EMG), which is a test that records the electrical activity of the muscles. Individuals with mitochondrial myopathy will usually show more abnormalities on EMG testing. Mitochondrial myopathy is very difficult to diagnose. There is no singular test that says, “Yes, you have this.” Most of the time, individuals go undiagnosed.