Which mitochondrial disorder may present with symptoms including strokes and exercise intolerance?

The chosen answer, Mitochondrial Encephalopathy Lactic Acidosis and Stroke-like Episodes (MELAS), is the correct response as it directly describes a specific mitochondrial disorder characterized by a combination of neurological symptoms, metabolic disturbances, and significant stroke-like episodes. Individuals with MELAS often experience recurrent headaches, seizures, and cognitive decline, which are consistent with stroke-like episodes.

Additionally, they may have exercise intolerance due to the impaired energy production characteristic of mitochondrial dysfunction. This leads to fatigue and muscle weakness during physical activity, which is a notable part of their symptomatology.

In contrast, while POLG related disorders may also involve neurological aspects and can lead to various myopathic features, they are not specifically associated with the classic presentation of stroke-like events as seen in MELAS. Kearns-Sayre syndrome typically presents with progressive external ophthalmoplegia, pigmentary retinopathy, and cardiac conduction defects rather than strokes. Sengers syndrome is characterized by hypertrophic cardiomyopathy and exercise intolerance with lactic acidosis, but it does not emphasize stroke-like episodes as a key symptom. Therefore, MELAS is uniquely identified by the presence of stroke-like episodes alongside exercise intolerance, making it the most accurate answer in this context