A recent study has found that reaching a correct diagnosis can be extremely challenging for people with mitochondrial disease, reports MedicalMalpractise. Patients are likely to have to undergo numerous different tests, speak to many doctors, and, for a significant proportion, have multiple misdiagnoses before mitochondrial disease is identified.
A large part of the reason this process is so difficult is the nature of the disease. The incidence rate is estimated to be 1 out of every 4,000 people in the U.S., but this is probably an underestimation of the actual number due to the difficulties around diagnosing the disease. Mitochondrial disease is usually caused by genetic mutations, and because it affects mitochondria, which are present in every cell, it can affect any body organ or tissue. This means that patients can exhibit a wide range of symptoms, the most common of which include limited growth, muscle weakness, seizures, developmental delays, hearing or vision impairment, and heart or liver disease. Furthermore, each patient will have a unique combination of cells that are affected. However, there are some combinations of symptoms that occur relatively frequently, and these have been grouped into subcategories of mitochondrial disease, like Leigh’s disease and Alper’s disease.
This range of symptoms makes mitochondrial disease difficult to identify. This problem is compounded by how difficult it is to test for mitochondrial disease, even when a doctor suspects it. Tests such as blood testing, muscle biopsies, MRI scans, and spinal fluid tests are often helpful, but can be misleading. Results from these tests can look ‘normal’ even when the patient has the disease. More recently, genetic testing has emerged as a possible way to identify the disease. However, it requires specialist equipment and is often expensive for patients. The combination of diverse symptoms and often inconclusive testing means that mitochondrial disease is frequently overlooked, which can be frustrating for patients who remain undiagnosed or incorrectly diagnosed.