A 71-year-old female presented with diplopia, ptosis, and nyctalopia. At 76 years, she had bilateral reduced visual acuity, reduced color vision, central scotomas, ptosis, and ophthalmoplegia. MRI showed thinned extraocular muscles, and a flash electroretinogram showed reduced cone function and borderline rod-function, bilaterally. In addition to ocular findings, the patient also had mild gait ataxia, progressive extremity weakness, and adrenal insufficiency. A quadriceps muscle biopsy showed the presence of a few ragged red fibers, which was nonspecific for her age.
She was suspected to have a mitochondrial disorder, therefore, a blood specimen and then, two months later, muscle tissue were sent for mitochondrial genome analysis.
|Nicole Boczek, Ph.D.
Fellow, Clinical Molecular Genetics
|Linda Hasadsri, M.D., Ph.D.
Senior Associate Consultant, Laboratory Genetics and Genomics
Assistant Professor of Laboratory Medicine and Pathology
Mayo Clinic College of Medicine