Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-Like Episodes (MELAS)

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a well-recognized clinical mitochondrial disease which causes typical symptoms of short stature, failure to thrive, recurrent headaches and vomiting, stroke-like episodes causing hemiplegia or vision loss, epilepsy, hearing loss, and diabetes. Additional manifestations include other endocrinopathies and cardiac involvement. MELAS is typically caused by a mitochondrial DNA point mutation (m.3243A>G) and is therefore maternally inherited. It is not at all unusual to find additional family members who are also affected or may be oligosymptomatic with other clinical phenotypes caused by this pathogenic variant such as maternally inherited diabetes and deafness (MIDD). Recognition of MELAS is critically important to ensure proper long-term surveillance and potential therapies. MELAS leads to overall morbidity and mortality due to recurrent stroke-like episodes, cerebral atrophy, and physical and mental deterioration over time.