A Rare m.4171C>A (MT-ND1), p.(Leu289Met) Mutation in Leber’s Hereditary Optic Neuropathy: A Case Series from a Lebanese Armenian Family and a French Patient

To describe the clinical features of five patients with the rare m.4171C>A (MT-ND1), p.(Leu289Met) mutation associated with Leber’s Hereditary Optic Neuropathy (LHON). A retrospective analysis was conducted on four Lebanese Armenian patients and one French patient, all with the m.4171C>A (MT-ND1), p.(Leu289Met) mutation. Clinical data, including visual acuity, fundus examination, optical coherence tomography, and genetic testing, were reviewed. Ethical approval and consent were waived by the Institutional Review Board (IRB) as the report contains no identifiable patient information and has less than minimal risk. Verbal consent was obtained from all participants to publish their cases. The m.4171C>A (MT-ND1), p.(Leu289Met) mutation was associated with poor visual outcomes. Despite some reported improvement in visual acuity in three patients, most remained legally blind. The clinical presentation varied, with onset ages ranging from adolescence to 53 years. This variability underscores the unpredictable nature of LHON with this mutation. The m.4171C>A (MT-ND1), p.(Leu289Met) mutation in LHON demonstrates significant clinical variability and generally poor visual prognosis. Early diagnosis and genetic counseling are critical for managing expectations and planning treatment.