Published online Sep 26, 2022. doi: 10.12998/wjcc.v10.i27.9945
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.
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.