education / DIAGNOSIS
Traditionally, the diagnosis of mitochondrial disease required a muscle biopsy (the procedure performed under anaesthetic that sampled a small piece of muscle tissue, to be examined under the microscope). However, research has shown that changes seen in a muscle biopsy may not always be present in affected persons. More recently, the diagnosis of mitochondrial disease has included the use of genetic studies. Genetic studies show that mutations in both mitochondrial and nuclear DNA can cause mitochondrial disease. The disease may be transmitted (that is, run in families), but may also occur sporadically (i.e. in isolation). Multiple investigations are often required to diagnose and assess a patient with mitochondrial disease. These should be discussed with a medical practitioner.