Man LiZong‐Han LinYing‐Cheng ChenPan LinYong Xin XieJames Cheng‐Chung Wei2026-02-032026-02-032023-09-2210.1111/1756-185X.14906https://scholars.csmu.edu.tw/handle/123456789/4826<jats:title>Abstract</jats:title><jats:p>A 35‐year‐old male patient presented fluctuating bilateral lower extremity weakness for 3 years. Physical examination showed grade 4 proximal muscle weakness in both lower extremities and grade 5 distal muscle weakness. Laboratory data revealed elevated creatine kinase, triglycerides, and cholesterol. Muscle pathology showed deposition of lipid droplet under the sarcolemma. Bone densitometry indicated severe osteoporosis. Next‐generation sequencing revealed a pathogenic mutation in the ETFDH gene. The patient was diagnosed with late‐onset multiple acyl‐CoA dehydrogenase deficiency. After riboflavin treatment, symptoms of the patient were relieved, physical endurance was restored, and bone mineral density was improved.</jats:p>journal-article