Acute Bilateral Vision Loss in a Young Male: A Case of Leber’s Hereditary Optic Neuropathy

Leber’s Hereditary Optic Neuropathy (LHON) is a rare mitochondrial genetic disorder that primarily affects young adult males, leading to acute or subacute painless central vision loss. The condition results from point mutations in mitochondrial DNA, most commonly affecting the ND1, ND4, or ND6 genes, which impair the function of complex I in the mitochondrial respiratory chain. This leads to selective degeneration of retinal ganglion cells and the optic nerve, causing severe and often…

Uncovering the Characteristics of Pupil Cycle Time (PCT) in Neuropathies and Retinopathies

Pupil cycle time (PCT) estimates the dynamics of a biofeedback loop established between pupil size and stimulus luminance, size or colour. The PCT is useful for probing the functional integrity of the retinopupillary circuits, and is therefore potentially applicable for assessing the effects of damage due to retinopathies or neuropathies. In previous studies, PCT was measured by manually counting the number of pupil oscillations during a fixed period to calculate the PCT. This method is scarce,…

Leber’s Hereditary Optic Neuropathy

CONCLUSION: Although still uncommon, the presentation of LHON in middle-aged women is possible and should be considered as one of the differential diagnoses in a patient when painless vision loss occurs.

Mitochondrial DNA Pathogenic Variant Prevalence in Primary Mitochondrial Disease Patients With African (L) Mitochondrial Genome Haplogroups

Primary mitochondrial diseases (PMD) are caused by pathogenic variants in over 350 genes, 37 of which are located in mitochondrial DNA (mtDNA). While more than 100 mtDNA variants have confirmed disease associations, there are few reports of mtDNA-related PMD in patients with African heritage, even in well-studied populations. We investigated the frequency of pathogenic mtDNA variants in African L-haplogroups in patients with confirmed PMD from two diagnostic cohorts. Data from genetically…

Leber’s hereditary optic neuropathy-associated ND1 3733G> C mutation ameliorates the mitochondrial quality control and cellular homeostasis

Leber’s hereditary optic neuropathy (LHON) is a paradigm for mitochondrial retinopathy due to mitochondrial DNA (mtDNA) mutations. However, the mechanism underlying LHON-linked mtDNA mutations, especially their impact on mitochondrial and cellular integrity, is not well understood. Recently, the ND1 3733G>C (p.E143Q) mutation was identified in three Chinese pedigrees with suggestively maternal inheritance of LHON. In this study, we investigated the pathogenic mechanism of m.3733G>C mutation…

Optic nerve MRI findings in Leber’s hereditary optic neuropathy

CONCLUSION: MRI lesions can extend from the intraorbital optic nerve to the chiasm and tract. Consistent with previous reports, chiasmal involvement was frequently observed and was more prevalent in younger patients. Recognition of these characteristic MRI and clinical findings is crucial in the differential diagnosis of subacute progressive optic neuropathy.

Early-Onset Hearing Loss in Leber’s Hereditary Optic Neuropathy: A Case Report

Leber hereditary optic neuropathy (LHON) is one of the most common mitochondrial disorders that is characterized in young adults and teenagers as bilateral, painless, subacute visual failure. Extraocular manifestations include neurological and cardiac features. Sensorineural hearing loss (SNHL) has not been reported as a clinical feature of this disorder. We report a patient diagnosed with LHON having the common m.11778G>A; p. Arg340 pathogenic variant who was also diagnosed with bilateral…

Nitric Oxide may Adversely Affect the Metabolism and Viability of Retinal Organoids Derived from Patients with Leber Hereditary Optic Neuropathy

Leber hereditary optic neuropathy (LHON) is a bilateral optic neuropathy associated with mitochondrial DNA (mtDNA) mutations characterized by parapapillary telangiectasia during the acute phase. However, its precise mechanism remains unclear. This study evaluated the effects of nitric oxide (NO) on retinal organoids (ROs) generated from induced pluripotent stem (iPS) cells derived from patients with LHON. Established iPS cells from three patients with the m.11778G>A mutation (patient group) and…