Case Report
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Sep 26, 2022; 10(27): 9945-9953
Published online Sep 26, 2022. doi: 10.12998/wjcc.v10.i27.9945
Familial mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episode syndrome: Three case reports
Xiao Yang, Le-Jun Fu
Xiao Yang, Le-Jun Fu, Department of Medical Imaging, Tianjin Huanhu Hospital, Tianjin 300350, China
Author contributions: Yang X was responsible for the data collection and drafted the manuscript; Fu LJ was responsible for interpreting the data and supervised the manuscript preparation; all authors have read and approved the final manuscript.
Informed consent statement: Informed written consent has been obtained from the patient for the publication of this report and any accompanying images.
Conflict-of-interest statement: All authors report no relevant conflict of interest for this article.
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Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Le-Jun Fu, MM, Attending Doctor, Department of Medical Imaging, Tianjin Huanhu Hospital, No. 6 Jizhao Road, Jinnan District, Tianjin 300350, China.
Received: May 21, 2022
Peer-review started: May 21, 2022
First decision: July 29, 2022
Revised: August 12, 2022
Accepted: August 21, 2022
Article in press: August 21, 2022
Published online: September 26, 2022

Mitochondrial encephalomyopathy (ME) is a multisystem metabolic disease that primarily affects the central nervous system and skeletal muscle. It is caused by mutations in mitochondrial or nuclear DNA, resulting in abnormal mitochondrial structure and function and insufficient ATP synthesis. The most common subtype is mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episode (MELAS) syndrome. In recent years, reports of MELAS syndrome have increased but familial cases are rare.


We report a case of familial MELAS syndrome. Cases 2 and 3 are sisters and case 1 is their nephew. All are short in stature and showed stroke-like episodes with rapid onset and no obvious symptoms such as paroxysmal headache, aphasia, or blurred vision. After admission, blood lactate levels were significantly higher than normal. The patients underwent magnetic resonance imaging of the head. Cases 1 and 2 were considered to have ME, whereas case 3 was considered to have a space-occupying lesion in the left temporal lobe. Pathological evaluation showed no obvious tumor cells in the brain lesions of case 3. Muscle biopsy or genetic test results were consistent with ME. The patients were diagnosed with MELAS syndrome and their symptoms improved with intravenous infusions of coenzyme Q10, coenzyme A, vitamin B, and vitamin C. At the 6 mo follow-up, there was no recurrence or progression.


When a patient has MELAS syndrome, familial MELAS syndrome should be considered if related family members have similar symptoms.

Keywords: Mitochondrial encephalomyopathy, Magnetic resonance imaging, Genetic testing, Pathological results, Case report

Core Tip: Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episode (MELAS) syndrome is a hereditary metabolic disease with complex clinical manifestations, and is often misdiagnosed as cerebral infarction and encephalitis. When the patient has a family history of this disease, blood lactate level is higher than normal, and imaging examination suggests MELAS syndrome, the possibility of MELAS syndrome should be considered. The diagnosis should be confirmed by muscle biopsy and genetic testing.