RESUMO
BACKGROUND: Mitochondrial optic neuropathy is characterized by painless, progressive, symmetrical central vision loss, and dyschromatopsia owing to mitochondrial dysfunction. This report documents a rare case of mitochondrial optic neuropathy due to the SIRT3 gene mutation. CASE PRESENTATION: This report describes a case of a 17-year-old boy who presented with symptoms of bilateral painless, progressive vision decline over several years. Fundus examination revealed temporal pallor of the optic nerve head in both the eyes and an OCT showed considerable thinning of the retinal nerve fiber and ganglion cell layers. Pathogenicity was confirmed by decreased mitochondrial function measured by bioenergetic health index and oxygen consumption rate in this patient. Subsequent NGS revealed a missense mutation of the SIRT3 gene (c.1137G > C, p.Trp379Cys) in the patient. CONCLUSIONS: This case describes the clinical manifestation of mitochondrial optic neuropathy due to the SIRT3 gene mutation.