Genetic Data Are a Prerequisite for Interpreting Clinical and Muscle Biopsy Findings in MELAS

With interest we read the article by Baek, et al.1 concerning the usefulness of muscle biopsy findings for diagnostic workup in patients with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. The authors concluded that muscle biopsy is of limited relevance for establishing the diagnosis MELAS.1 There are some concerns with regard to the reliability of the presented data