Zhonghua Yan Ke Za Zhi. 2011 Dec; 47(12): 1080-3
She CY, Gu H, Xu J, Ma K, Liu NP

To identify the disease-causing mutation in a family of Leber hereditary optic neuropathy (LHON).Clinical data and family information were collected. Peripheral venous blood was drawn from patients and family members who agreed to donate the blood samples. Genomic DNA was extracted from blood leukocytes. Three primary mitochondrial DNA (mtDNA) mutations, G3460A, G11778A, and T14484C were screened using a method of polymerase chain reaction (PCR) followed by direct sequencing.This 3-generation family had 14 members. Seven family members were affected, including 5 female patients and 2 male patients. Pedigree analysis showed maternal inheritance. Mutation analysis in 4 affected and 3 unaffected family members showed G11778A mutation in all 4 affected and 2 of the 3 unaffected individuals.G11778A mutation in mtDNA is the disease-causing mutation in this family of LHON. For the mutation carriers, early intervention may prevent or delay the onset of the disease.

J Neuroophthalmol. 2012 Mar; 32(1): 95-96
Hashemi N, Yalamanchili SS, Zhang J, Lee AG

J Neuroophthalmol. 2012 Mar; 32(1): 54-7
Sabet-Peyman EJ, Khaderi KR, Sadun AA

ABSTRACT: A 31-year-old woman developed subacute bilateral visual loss over a 2-week period. Two months later, the diagnosis of Leber hereditary optic neuropathy (LHON) 11778/ND4 was established and the patient was treated with 900 mg of idebenone daily. Over the ensuing 9 months, visual acuity improved from 20/200 to 20/25 in each eye with near-total resolution in visual field abnormalities. Our case report is in agreement with 2 large published series of patients with LHON treated with idebenone, raising hope for treatment of this visually devastating mitochondrial disorder.

Acta Anaesthesiol Scand. 2012 Jan 19;
Vanlander AV, Jorens PG, Smet J, DE Paepe B, Verbrugghe W, VAN DEN Eynden GG, Meire F, Pauwels P, VAN DER Aa N, Seneca S, Lissens W, Okun JG, VAN Coster R

Propofol is an anesthetic agent widely used for induction and maintenance of anesthesia, and sedation in children. Although generally considered as reliable and safe, administration of propofol can occasionally induce a potentially fatal complication known as propofol infusion syndrome (PRIS). Mitochondrial dysfunction has been implicated in the pathogenesis of PRIS. We report on an adult patient with Leber hereditary optic neuropathy (LHON) who developed PRIS. He was a carrier of the m.3460G>A mutation, one of the major three pathogenic point mutations associated with LHON. The propositus was blind and underwent propofol sedation after severe head injury. Five days after start of propofol infusion, the patient died. The activity of complex I of the oxidative phosphorylation (OXPHOS) system was severely deficient in skeletal muscle. Our observation indicates that fulminate PRIS can occur in an adult patient with an inborn OXPHOS defect and corroborates the hypothesis that PRIS is caused by inhibition of the OXPHOS system.

Front Biosci (Elite Ed). 2012; 4: 1830-5
Tonska K, Bartnik E

Men and women not only look different, but they have different risks of multiple diseases like migraine, neurodegenerative disorders or numerous cancers. Even the nerve cells may die in different ways and exhibit different sensitivity to pro-apoptotic factors. Some of the differences can be explained by the action of sex hormones, but the experiments on four core genotype mouse model, in which XX and XY mice can be of either sex showed that not all differences are due to hormones. An example of a disease with no simple explanation of sex bias is Leber hereditary optic neuropathy, a mitochondrial disease with about 4:1 male to female ratio. The apoptotic death of retinal ganglion cells forming an optic disc is a proposed mechanism of the disease pathophysiology. The mechanisms causing different sensitivity of the nerve cells of male and female subjects may be responsible for the gender bias in LHON and merit further studies.

Mol Vis. 2011; 17: 3175-9
Amaral-Fernandes MS, Marcondes AM, Miranda PM, Maciel-Guerra AT, Sartorato EL

There are many similarities in the clinical presentation of Leber hereditary optic neuropathy (LHON) and in patients who have optic neuropathy and a history of heavy tobacco and alcohol consumption. The main objective of this study is to investigate the frequency of primary and secondary mitochondrial DNA (mtDNA) mutations for LHON in patients diagnosed as having alcohol and tobacco optic neuropathy (ATON).Twenty-six patients who had a history of heavy alcohol and tobacco consumption and who developed bilateral optic neuropathy were tested for primary mutations (G11778A, T14484C, and G3460A) by restriction analysis, and 14 secondary mutations in the genes mitochondrially encoded NADH dehydrogenase 1 (MT-ND1), mitochondrially encoded NADH dehydrogenase 4 (MT-ND4), mitochondrially encoded NADH dehydrogenase 4L (MT-ND4L), mitochondrially encoded NADH dehydrogenase 5 (MT-ND5), mitochondrially encoded NADH dehydrogenase 6 (MT-ND6), and mitochondrially encoded cytochrome B (MT-CYB) by direct sequencing.Four (15.4%) of 26 patients tested positive for LHON primary mutations, two for the G11778A mutation, and two for the T14484C mutation. No patient tested positive for any of the 14 secondary mutations. Familial recurrence was present in four patients, and only three of these patients have presented the LHON mutation.The diagnosis of LHON should be considered in all patients diagnosed as having optic neuropathy, particularly those with familial recurrence of vision loss.

PLoS One. 2011; 6(11): e27750
Zhang AM, Jia X, Bi R, Salas A, Li S, Xiao X, Wang P, Guo X, Kong QP, Zhang Q, Yao YG

Recent studies have shown that mtDNA background could affect the clinical expression of Leber hereditary optic neuropathy (LHON). We analyzed the mitochondrial DNA (mtDNA) variation of 304 Chinese patients with m.11778G>A (sample #1) and of 843 suspected LHON patients who lack the three primary mutations (sample #2) to discern mtDNA haplogroup effect on disease onset. Haplogroup frequencies in the patient group was compared to frequencies in the general Han Chinese population (n = 1,689; sample #3). The overall matrilineal composition of the suspected LHON population resembles that of the general Han Chinese population, suggesting no association with mtDNA haplogroup. In contrast, analysis of these LHON patients confirms mtDNA haplogroup effect on LHON. Specifically, the LHON sample significantly differs from the general Han Chinese and suspected LHON populations by harboring an extremely lower frequency of haplogroup R9, in particular of its main sub-haplogroup F (#1 vs. #3, P-value = 1.46×10(-17), OR = 0.051, 95% CI: 0.016-0.162; #1 vs. #2, P-value = 4.44×10(-17), OR = 0.049, 95% CI: 0.015-0.154; in both cases, adjusted P-value <10(-5)) and higher frequencies of M7b (#1 vs. #3, adjusted P-value = 0.001 and #1 vs. #2, adjusted P-value = 0.004). Our result shows that mtDNA background affects LHON in Chinese patients with m.11778G>A but not suspected LHON. Haplogroup F has a protective effect against LHON, while M7b is a risk factor.

Biochim Biophys Acta. 2012 Feb; 1817(2): 312-8
Pätsi J, Maliniemi P, Pakanen S, Hinttala R, Uusimaa J, Majamaa K, Nyström T, Kervinen M, Hassinen IE

Defects in complex I due to mutations in mitochondrial DNA are associated with clinical features ranging from single organ manifestation like Leber hereditary optic neuropathy (LHON) to multiorgan disorders like mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome. Specific mutations cause overlap syndromes combining several phenotypes, but the mechanisms of their biochemical effects are largely unknown. The m.3376G>A transition leading to p.E24K substitution in ND1 with LHON/MELAS phenotype was modeled here in a homologous position (NuoH-E36K) in the Escherichia coli enzyme and it almost totally abolished complex I activity. The more conservative mutation NuoH-E36Q resulted in higher apparent K(m) for ubiquinone and diminished inhibitor sensitivity. A NuoH homolog of the m.3865A>G transition, which has been found concomitantly in the overlap syndrome patient with the m.3376G>A, had only a minor effect. Consequences of a primary LHON-mutation m.3460G>A affecting the same extramembrane loop as the m.3376G>A substitution were also studied in the E. coli model and were found to be mild. The results indicate that the overlap syndrome-associated m.3376G>A transition in MTND1 is the pathogenic mutation and m.3865A>G transition has minor, if any, effect on presentation of the disease. The kinetic effects of the NuoH-E36Q mutation suggest its proximity to the putative ubiquinone binding domain in 49kD/PSST subunits. In all, m.3376G>A perturbs ubiquinone binding, a phenomenon found in LHON, and decreases the activity of fully assembled complex I as in MELAS.

Rinsho Shinkeigaku. 2011 Oct; 51(10): 781-3
Hayashi S, Okamoto K

A previously healthy 34-year-old man sustained multiple skull fractures in a traffic accident. Radiological findings and visual field examination did not detect any abnormality. Shortly after the accident, he noticed blurred vision in both eyes. Six months after the accident, he gradually developed disturbance of visual acuity in the right eye. His best corrected visual acuity (BCVA) was 0.8 OD and 1.2 OS and brain MRI did not show any abnormality, while Humphrey visual field analysis demonstrated right homonymous hemianopsia. Two months after the initial presentation, his BCVA showed 0.1 OD and 0.08 OS. Visual field examination suggested that both right homonymous hemianopsia and left blind spot had become enlarged. Mitochondrial DNA analysis demonstrated G11,778A mutation and a diagnosis of Leber's hereditary optic neuropathy (LHON) was made. A few reports have documented mild acute insult to the head or blunt optic trauma as triggers of optic neuropathy in subjects with LHON. Although, the precise mechanism of LHON following trauma remains unknown, it appears that an acute insult may be sufficient to precipitate neuropathy in the optic nerve already compromised by mitochondrial dysfunction. Asymptomatic carriers should be advised to avoid possible precipitating factors such as head trauma.

J Child Neurol. 2011 Oct; 26(10): 1332-4
Frye RE

J Child Neurol. 2011 Oct; 26(10): 1331-2
Castro-Gago M, Pérez-Gay L, Eirís-Puñal J

Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2011 Oct; 28(5): 501-6
Zhang Y, Zhang JJ, Ji YC, Zhang ML, Tong Y, Zhao FX, Qu J, Zhou XT, Guan MX

To explore clinical, genetic and molecular features of two Chinese Han families with Leber's hereditary optic neuropathy (LHON).Ophthalmologic examinations revealed variable severity and age-at-onset of visual loss among probands and other matrilineal relatives of both families. The families exhibited extremely low penetrance of visual impairment. The entire mitochondrial genome of two probands was amplified by PCR in 24 overlapping fragments using sets of oligonucleotide primers.Sequence analysis of complete mitochondrial genome in the pedigrees excluded three common LHON associated mutations G11778A, G3460A and T14484C, but revealed the presence of a known homoplasmic tRNA(Thr) A15951G mutation. It also showed distinct sets of mtDNA polymorphisms belonging to Eastern Asian haplogroup D4b1. The A15951G mutation is located at the extremely conserved nucleotide (conventional position 71) of tRNA(Thr). Thus, this mutation may alter the structure and stability of mitochondrial tRNA(Thr), thereby leading to a failure in the tRNA metabolism and mitochondrial dysfunction, causing visual impairment.The results suggested that the A15951G mutation might be involved in the pathogenesis of Leber's hereditary optic neuropathy in the two families.