Mitochondrial diseases are an important group of inherited neurometabolic disorders that invariably exhibit multi-organ involvement, are relentlessly progressive, and result in significant morbidity and mortality. They may manifest as discrete clinical syndromes such as mitochondrial encephalomyopathy, lactic acidosis, and stroke like episodes (MELAS), chronic and progressive external ophthalmoplegia (CPEO), and maternally inherited deafness and diabetes (MIDD), or more commonly with a wide overlapping spectrum of clinical features, including hypertrophic cardiomyopathy and gastrointestinal (GI) dysmotility (Gorman et al., 2016; Taylor & Turnbull, 2005).