A Case of Mitochondrial Disease First Diagnosed Over 30 Years After Onset

Abstract

Mitochondrial disease is induced by mutations in both mitochondrial DNA and DNA of nuclear genes that encode mitochondrial proteins, and there is a general lack of genotype-phenotype correlation in many mitochondrial disorders, which makes the diagnosis of mitochondrial disease difficult. We treated a 37-year-old woman with congenital cataract, bilateral sensory deafness, severe bilateral ptosis, oculomotor disorder in all directions and systemic muscular atrophy and weakness. These clinical characteristics made us perform further examinations, and we found ischemic change in brain and remarkable atrophy of extraocular muscles by magnetic resonance imaging (MRI), optic atrophy by fundus examination and high levels of serum lactate and lactate/pyruvate ratio, which confirmed the diagnosis of mitochondrial disease. Finally, she was diagnosed with having mitochondrial disease for over 30 years after onset. J Endocrinol Metab. 2018;8(6):149-152 doi: https://doi.org/10.14740/jem542