The A8344G mutation in mitochondrial DNA associated with stroke-like episodes and gastrointestinal dysfunction.
We report an unusual case of encephalo-entero-myopathy associated with the A8344G mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA). This patient had mitochondrial myopathy, multiple lipomatosis, mild hearing loss, stroke-like episodes, and paralytic ileus, but she lacked the canonical clinical features of MERRF, myoclonus, epilepsy, or ataxia. We conducted genetic, biochemical, histochemical, and immunohistochemical studies in skeletal muscle, brain, intestine, and lipoma tissue. The mutation was abundant in all tissues, and cytochrome c oxidase (COX) activity was selectively decreased in brain and small intestine. COX deficiency was also documented histochemically and immunohistochemically in the small intestine, suggesting that mitochondrial dysfunction played a role in the pathogenesis of paralytic ileus. This case illustrates an unusual and dramatic clinical phenotype of the A8344G mutation, characterized by stroke-like episodes and acute ileus.
Tanji
Kurenai
K
Department of Pathology of the College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA.
Gamez
Josep
J
Cervera
Carles
C
Mearin
Fermin
F
Ortega
Arantxa
A
de la Torre
Javier
J
Montoya
Julio
J
Andreu
Antoni L
AL
DiMauro
Salvatore
S
Bonilla
Eduardo
E
D000328:Adult; D001921:Brain / Q000201:enzymology; D030401:Cytochrome-c Oxidase Deficiency / Q000150:complications; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D005767:Gastrointestinal Diseases / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry; D007421:Intestine, Small / Q000201:enzymology; D017243:MERRF Syndrome / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D012357:RNA, Transfer, Lys / Q000235:genetics*; D020521:Stroke / Q000150:complications / Q000201:enzymology / Q000235:genetics* / Q000473:pathology
D004272:DNA, Mitochondrial; D012357:RNA, Transfer, Lys; D003576:Electron Transport Complex IV