title: Infantile mitochondrial disorder associated with subclinical hypothyroidism is caused by a rare mitochondrial DNA 8691A>G mutation: a case report.
abstract: Mitochondrial diseases, ~15% of cases, are because of mitochondrial DNA mutations. This study reported a case of an 11-month-old male infant with mitochondrial disease characteristics and subclinical hypothyroidism (a high thyrotropin level). Laboratory tests were all normal and the enzymatic activities of mitochondrial respiratory chain enzyme complexes I-IV were normal. However, thyroid tests showed abnormal results, and complex V showed a deficiency activity of 52.8% of the low limit of healthy individuals (normal activity is >60.7%). The patient experienced convulsions, and the 24-h ambulatory electroencephalography results showed abnormalities, but the electromyography results were normal. Axial brain MRI showed abnormal dysplasia over the white matter myelination in the bilateral horn of the lateral ventricle. Furthermore, DNA sequencing data showed a novel mutation at 8691A>G of the mitochondrial ATPase 6 gene. This case adds to the growing literature of mitochondrial disorders caused by mitochondrial ATPase 6 mutations.
authors.affiliation: aDepartment of Pediatric Neurology, The First Hospital of Jilin University bDepartment of Neurology, The China-Japan Union Hospital, Changchun, Jilin, China.
authors.forename: Xiaosheng
authors.initials: X
authors.lastname: Hao
authors.forename: Songyan
authors.initials: S
authors.lastname: Liu
authors.forename: Xuemei
authors.initials: X
authors.lastname: Wu
authors.forename: Yunpeng
authors.initials: Y
authors.lastname: Hao
authors.forename: Yinbo
authors.initials: Y
authors.lastname: Chen
mesh_terms: D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000235:genetics*; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D028361:Mitochondrial Diseases / Q000150:complications / Q000235:genetics*; D025261:Mitochondrial Proton-Translocating ATPases / Q000235:genetics; D009154:Mutation / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; C501005:MT-ATP6 protein, human; D025261:Mitochondrial Proton-Translocating ATPases