Leber's 'Plus' in a Korean Patient with 14484/ND6 Mutation

Leber hereditary optic neuropathy following head trauma and ocular trauma on contralateral eye: a case report

Purpose

To present a case of activation of Leber hereditary optic neuropathy (LHON) following head and ocular trauma of the fellow eye in the patient with no remarkable symptoms and normal visual acuity prior to trauma.

Case summary

A 31-year-old healthy man was referred to our hospital after a traffic accident. He had blowout fractures of medial and inferior orbital wall of the left eye, subcutaneous hematoma of the left forehead, and bony fragment that compressed the left optic nerve. Initially, best-corrected visual acuity (BCVA) was 20/20 in the right and 20/1000 in the left eyes. Relative afferent pupillary defect of the left eye was apparent, and fundus examination revealed choroidal rupture circumferentially crossing the macular area. Nine months later, the patient complained with gradual vision loss in the right eye, which was the contralateral eye of the ocular trauma. BCVA was 20/200, and perimetry revealed cecocentral scotoma in the right eye. BCVA in both eyes reduced to 20/2000 1 year post-trauma. Visual evoked potentials revealed markedly decreased in amplitudes and elongated latencies for both eyes. Mitochondrial DNA analysis revealed a G11778A mutation; therefore, a diagnosis of activation of LHON followed by trauma was made for the previously unaffected carrier.

Conclusions

This is a case in which activation of LHON occurred in a healthy carrier following head and ocular trauma of the fellow eye. This observation suggests the possibility that LHON activation in healthy carriers may occur in patients who experience head or ocular trauma even in the fellow eye.

Mutation analysis of Leber's hereditary optic neuropathy using a multi-gene panel

The present study investigates the spectrum and incidence of mitochondrial DNA (mtDNA) mutations associated with Leber's hereditary optic neuropathy (LHON) in a Han population using a multi-gene panel with 46 LHON-associated mutations among 13 mitochondrial genes. A total of 23 mutations were observed in a cohort of 275 patients and 281 control subjects using multi-gene panel analysis. The causative mutations associated with LHON were identified to be m.11778G>A, m.14484T>C, m.3460 G>A, m.3635G>A, m.3866T>C and m.3733G>A, responsible for 70.55% cases in the patient cohort. The secondary mutations in the Chinese LHON population were m.12811T>C, m.11696 G>A, m.3316G>A, m.3394T>C, m.14502T>C, m.3497C>T, m.3571C>T, m.12338T>C, m.14693A>G, m.4216T>C and m.15951A>G, with incidences of 5.09, 4.36, 4.00, 4.00, 4.00, 2.55, 1.82, 1.82, 1.45, 1.09 and 1.09%, respectively. Besides three hotspot genes, MT-ND1, MT-ND4 and MT-ND6, MT-ND5 also had a high incidence of secondary mutations. Those mutations reported as rare causative mutations in a European LHON population, m.3376G>A, m.3700G>A and m.4171C>A, m.10663T>C, m.13051G>A, m.14482C>G/A, m.14495A>G and m.14568C>T were undetected in the present study. The primary and secondary mutations associated with LHON in the present multi-gene panel will advance the current understanding of the clinical phenotype of LHON, and provide useful information for early diagnosis.