Inherited mitochondrial disease

Inherited disorders that affect mitochondrial function are an exceedingly diverse group of conditions with different pathophysiological mechanisms and highly variable clinical phenotypes. Paediatric patients may present with a defined clinical syndrome or, more commonly, with non-specific signs of mitochondrial disease. Recognition of mitochondrial disease relies on having a high index of suspicion when faced with a multisystem disorder of unclear aetiology, in addition to knowledge of the various defined mitochondrial clinical syndromes. However, diagnosis remains a particular challenge, owing to the lack of sensitive and specific biomarkers. Evidence of mitochondrial dysfunction should be sought from a variety of organ systems using both functional and biochemical testing, although recent advances in genomic technology are changing the approach to diagnosis. Treatment of mitochondrial disease also presents a significant challenge, since although a few disease specific therapies exist, treatment remains predominantly supportive. Some cofactors, vitamins and antioxidants are commonly used to enhance mitochondrial function, although there is little evidence to support their efficacy.