Leber's hereditary optic neuropathy mitochondrial DNA mutations at nucleotides 11778 and 3460 in multiple sclerosis

Poor visual prognosis of Asian patients with 3460 mitochondrial DNA mutation in Leber's hereditary optic neuropathy

BACKGROUND

Among the 3 primary mutations of Leber's hereditary optic neuropathy (LHON), the incidence of LHON with a mutation at nucleotide position 3460 is the lowest in Asians. Therefore, information about the clinical manifestations of LHON mutations in Asians with the 3460 mutation is limited.

OBJECTIVE

To determine the clinical manifestations including visual prognosis of Asians with the LHON 3460 mutation.

METHODS

We performed a retrospective study of 5 Korean LHON patients with the 3460 mutation.

RESULTS

All patients were male, and the age of onset for visual impairment varied from 17 to 35 years, with an average of 25.4 ± 7.16 years. Among the 10 affected eyes, only 1 eye of 1 patient showed visual improvement to 20/50 at 2 years after onset. The remaining patients had a visual acuity of worse than 20/200.

CONCLUSION

The visual prognosis of Korean patients with the LHON 3460 mutation was generally poor. Further studies regarding Asian patients with the LHON 3460 mutation are necessary.

Leber Mitochondrial Optic Neuropathy in Pediatric Females With Focus on Very Early Onset Cases

The aim of this study was to describe the phenotype of Leber hereditary optic neuropathy occurring in pediatric females. This disease generally affects young adult males, but it can occur also in females, and research data in this population is lacking. The very early onset can challenge the diagnosis and delay treatment. We searched PubMed through February 2021 and identified 226 pediatric females with genetically confirmed Leber hereditary optic neuropathy and added a new case of a 3-year-old female. The male-female ratio was 1.8:1; the mean onset age in females was 11 years with the onset at 3 years of age occurring in 3 females only. Acute onset with mild visual impairment was the most common presentation, associated with optic disc edema in 16%. Differential diagnoses are pseudotumor cerebri, optic nerve drusen and optic neuritis. The outcome is poor with partial recovery in 50%, despite some receiving Idebenone therapy.

Analysis of Visual Field Defects Obtained with Semiautomated Kinetic Perimetry in Patients with Leber Hereditary Optic Neuropathy

Purpose

To analyse visual field (VF) defects obtained using semiautomated kinetic perimetry (SKP) in patients suffering from Leber hereditary optic neuropathy (LHON).

Methods

Twenty-two eyes of eleven consecutive LHON male patients with confirmed mitochondrial 11778G>A DNA mutation were prospectively examined with the V4e stimulus of SKP in both eyes. The mean time after the onset of LHON was one year. The area of obtained isopters was measured in square degrees (deg²). Additionally, static automated perimetry (SAP) within 30° was performed.

Results

Visual acuity ranged from counting fingers to 50 cm to 0.4. VFs obtained with SKP showed central scotomas in 18 eyes (82%); the periphery of the VF in these eyes remained intact. The mean area of central scotoma was 408.8 deg², and the mean area of the peripheral VF was 12291.1 deg²; SAP also revealed central scotoma in these patients. In four eyes (18%) with the worst visual acuity, only the residual central island of VF was found using SKP (mean area 898.4 deg²). SAP was difficult to obtain in these patients.

Conclusions

SKP provides additional clinical information in regard to the visual function of LHON patients. SKP enables the quantification of the area of central scotoma, preserved peripheral VF, and residual central island of vision. Using V4 stimulus is especially useful in LHON patients with poor visual acuity, when SAP is difficult to obtain.

Multiple sclerosis associated with Leber's Hereditary Optic Neuropathy

The cause of multiple sclerosis is unknown although it is recognised to involve an inflammatory process associated with demyelinating plaques and more widespread neurodegeneration. It appears to have become progressively more common in females which is further discussed in this issue, and genetic factors, as identified to date, appear to play only a moderate role. One curious observation is that Leber's Hereditary Optic Neuropathy (LHON), a rare genetic syndrome, presents clinically overwhelmingly in males, but can be associated with an MS-like illness and when it does it occurs mainly in females. It is interesting to examine this further to assess if this could give us any clues as to the pathogenesis of MS.

Optic neuropathy related to hydrogen peroxide inhalation

Optic neuropathy related to toxins is a complex, multifactorial disease potentially affecting individuals of all ages. We report a case of presumed toxic optic neuropathy secondary to H2O2 exposure. This has not been previously reported, and the temporal relationship of the exposure to the optic neuropathy is compelling, although not definite, evidence of a causal relationship.

Leber's hereditary optic neuropathy--case report and literature review

CONTEXT

Leber's hereditary optic neuropathy is an important cause of progressive painless visual loss among young male patients.

OBJECTIVE

To report on a case of a young patient with a clinical and neurophysiological condition suggestive of Leber's hereditary optic neuropathy, confirmed by genetic testing.

CASE REPORT

We describe a 17-year-old male with progressive bilateral visual loss. Two maternal uncles had had similar patterns of visual loss. The patient had a history of smoking and alcohol abuse. Neuro-ophthalmological examination revealed visual acuity of 20/800 in both eyes, with decreased direct and consensual pupillary light reflexes. Fundus examination demonstrated pale optic discs. The visual evoked potential test showed signs of conduction disturbances in both optic nerves and campimetric study showed complete visual loss in all fields of both eyes. A diagnosis of bilateral optic neuropathy with a clinical suspicion of Leber's hereditary optic neuropathy was made. A blood sample was submitted to genetic analysis in relation to the principal mutations of this disorder, and homoplasmic mutation in 11778 was detected, thereby confirming the diagnosis of Leber's hereditary optic neuropathy.

Lack of Association between Leber’s Hereditary Optic Neuropathy Primary Point Mutations and Multiple Sclerosis in Iran

The hypothesis that mitochondrial genes may implicate susceptibility to multiple sclerosis (MS) is supported by an increasing number of case reports on Leber's hereditary optic neuropathy (LHON)-associated mitochondrial DNA (mtDNA) point mutations in patients with MS. A number of mtDNA mutations with primary pathogenic significance for LHON, a maternally inherited disease causing severe bilateral visual loss predominantly in young men, have been detected in patients with an MS-like phenotype. To evaluate the link between MS and LHON primary point mutations, we investigated 31 non-related Iranian clinically definite MS patients (23 females and 8 males) with optic nerve involvement, as well as 25 patients (16 females and 9 males) without involvement of the optic nerve as controls. Three patients had severe bilateral visual loss without any recovery. We searched for the presence of LHON mitochondrial mutations at nucleotide positions (np) 11,778, 3,460, and 14,484 by mutation-specific polymerase chain reaction and restriction fragment length polymorphism. Our results suggest that there is no association between Iranian patients with MS and mtDNA point mutations at np 11,778, 3,460, and 14,484.

Leber's hereditary optic neuropathy mutations in Korean patients with multiple sclerosis

Several different mitochondrial DNA (mtDNA) sites for mutations of Leber's hereditary optic neuropathy (LHON) have been reported to be present in patients with multiple sclerosis (MS). To further study this association of LHON and MS in the Korean population, we tested 20 MS patients for the presence of mtDNA mutations at nucleotide (nt) 11778 in all 20 patients, and at nt 14484, nt 3460 and nt 15257 in 15, 12 and 12 patients, respectively. However, none of the MS patients exhibited any pathogenic LHON mtDNA mutations. In conclusion, we found no evidence for any association between MS and the LHON mutation in the Korean population.