Is the disease risk and penetrance in Leber hereditary optic neuropathy actually low?

Pedigree analysis showed that a large proportion of Leber hereditary optic neuropathy (LHON) family members who carry a mitochondrial risk variant never lose vision. Mitochondrial haplotype appears to be a major factor influencing the risk of vision loss from LHON. Mitochondrial variants, including m.14484T>C and m.11778G>A, have been added to gene arrays, and thus many patients and research participants are tested for LHON mutations. Analysis of the UK Biobank and Australian cohort studies found more than 1 in 1,000 people in the general population carry either the m.14484T>C or the m.11778G>A LHON variant. None of the subset of carriers examined had visual acuity at 20/200 or worse, suggesting a very low penetrance of LHON. Haplogroup analysis of m.14484T>C carriers showed a high rate of haplogroup U subclades, previously shown to have low penetrance in pedigrees. Penetrance calculations of the general population are lower than pedigree calculations, most likely because of modifier genetic factors. This Matters Arising Response paper addresses the Watson et al. (2022) Matters Arising paper, published concurrently in The American Journal of Human Genetics.

Transcriptomic and proteomic retinal pigment epithelium signatures of age-related macular degeneration.

There are currently no treatments for geographic atrophy, the advanced form of age-related macular degeneration. Hence, innovative studies are needed to model this condition and prevent or delay its progression. Induced pluripotent stem cells generated from patients with geographic atrophy and healthy individuals were differentiated to retinal pigment epithelium. Integrating transcriptional profiles of 127,659 retinal pigment epithelium cells generated from 43 individuals with geographic atrophy and 36 controls with genotype data, we identify 445 expression quantitative trait loci in cis that are asssociated with disease status and specific to retinal pigment epithelium subpopulations. Transcriptomics and proteomics approaches identify molecular pathways significantly upregulated in geographic atrophy, including in mitochondrial functions, metabolic pathways and extracellular cellular matrix reorganization. Five significant protein quantitative trait loci that regulate protein expression in the retinal pigment epithelium and in geographic atrophy are identified - two of which share variants with cis- expression quantitative trait loci, including proteins involved in mitochondrial biology and neurodegeneration. Investigation of mitochondrial metabolism confirms mitochondrial dysfunction as a core constitutive difference of the retinal pigment epithelium from patients with geographic atrophy. This study uncovers important differences in retinal pigment epithelium homeostasis associated with geographic atrophy.

Single-cell eQTL mapping identifies cell type-specific genetic control of autoimmune disease.

The human immune system displays substantial variation between individuals, leading to differences in susceptibility to autoimmune disease. We present single-cell RNA sequencing (scRNA-seq) data from 1,267,758 peripheral blood mononuclear cells from 982 healthy human subjects. For 14 cell types, we identified 26,597 independent cis-expression quantitative trait loci (eQTLs) and 990 trans-eQTLs, with most showing cell type-specific effects on gene expression. We subsequently show how eQTLs have dynamic allelic effects in B cells that are transitioning from naïve to memory states and demonstrate how commonly segregating alleles lead to interindividual variation in immune function. Finally, using a Mendelian randomization approach, we identify the causal route by which 305 risk loci contribute to autoimmune disease at the cellular level. This work brings together genetic epidemiology with scRNA-seq to uncover drivers of interindividual variation in the immune system.

Retinal ganglion cell-specific genetic regulation in primary open-angle glaucoma.

To assess the transcriptomic profile of disease-specific cell populations, fibroblasts from patients with primary open-angle glaucoma (POAG) were reprogrammed into induced pluripotent stem cells (iPSCs) before being differentiated into retinal organoids and compared with those from healthy individuals. We performed single-cell RNA sequencing of a total of 247,520 cells and identified cluster-specific molecular signatures. Comparing the gene expression profile between cases and controls, we identified novel genetic associations for this blinding disease. Expression quantitative trait mapping identified a total of 4,443 significant loci across all cell types, 312 of which are specific to the retinal ganglion cell subpopulations, which ultimately degenerate in POAG. Transcriptome-wide association analysis identified genes at loci previously associated with POAG, and analysis, conditional on disease status, implicated 97 statistically significant retinal ganglion cell-specific expression quantitative trait loci. This work highlights the power of large-scale iPSC studies to uncover context-specific profiles for a genetically complex disease.

Establishing risk of vision loss in Leber hereditary optic neuropathy.

We conducted an updated epidemiological study of Leber hereditary optic neuropathy (LHON) in Australia by using registry data to establish the risk of vision loss among different LHON mutations, sex, age at onset, and mitochondrial haplogroup. We identified 96 genetically unrelated LHON pedigrees, including 56 unpublished pedigrees, and updated 40 previously known pedigrees, comprising 620 affected individuals and 4,948 asymptomatic carriers. The minimum prevalence of vision loss due to LHON in Australia in 2020 was one in 68,403 individuals. Although our data confirm some well-established features of LHON, the overall risk of vision loss among those with a LHON mutation was lower than reported previously-17.5% for males and 5.4% for females. Our findings confirm that women, older adults, and younger children are also at risk. Furthermore, we observed a higher incidence of vision loss in children of affected mothers as well as in children of unaffected women with at least one affected brother. Finally, we confirmed our previous report showing a generational fall in prevalence of vision loss among Australian men. Higher reported rates of vision loss in males with a LHON mutation are not supported by our work and other epidemiologic studies. Accurate knowledge of risk is essential for genetic counseling of individuals with LHON mutations. This knowledge could also inform the detection and validation of potential biomarkers and has implications for clinical trials of treatments aimed at preventing vision loss in LHON because an overestimated risk may lead to an underpowered study or a false claim of efficacy.

The Effect of a 10-Week Physical Activity Programme on Fundamental Movement Skills in 3-4-Year-Old Children within Early Childhood Education Centres.

The objective of this study was to examine the effect of a 10-week physical activity (PA) programme, in early childhood education (ECE) settings, on 3 and 4-year-old children's fundamental movement skills (FMS). A further aim was to examine FMS three-months post-intervention. The PA instructors delivered one 45 min session/week over 10 weeks, to 3- and 4-year-old children (n = 46), across four ECE centres. These sessions involved participation from ECE teachers. Children in the control group (CON; n = 20) received no PA classes and completed pre- and post-intervention assessments only. Locomotor (e.g., running/hopping) and object-control (e.g., kicking/throwing) skills were assessed using the Test for Gross Motor Development-2 (TGMD-2), before and after the intervention and, for the intervention group (EXP), at 3 months. Locomotor and object-control skills significantly improved in the EXP group, with typically no change in the CON group. The EXP group's locomotor and object-control skills were maintained at 3 months. The 10-week PA intervention successfully improved 3- and 4-year-old children's FMS.

Longitudinal expression profiling of CD4+ and CD8+ cells in patients with active to quiescent giant cell arteritis.

BACKGROUND: Giant cell arteritis (GCA) is the most common form of vasculitis affecting elderly people. It is one of the few true ophthalmic emergencies but symptoms and signs are variable thereby making it a challenging disease to diagnose. A temporal artery biopsy is the gold standard to confirm GCA, but there are currently no specific biochemical markers to aid diagnosis. We aimed to identify a less invasive method to confirm the diagnosis of GCA, as well as to ascertain clinically relevant predictive biomarkers by studying the transcriptome of purified peripheral CD4+ and CD8+ T lymphocytes in patients with GCA. METHODS: We recruited 16 patients with histological evidence of GCA at the Royal Victorian Eye and Ear Hospital, Melbourne, Australia, and aimed to collect blood samples at six time points: acute phase, 2-3 weeks, 6-8 weeks, 3 months, 6 months and 12 months after clinical diagnosis. CD4+ and CD8+ T-cells were positively selected at each time point through magnetic-assisted cell sorting. RNA was extracted from all 195 collected samples for subsequent RNA sequencing. The expression profiles of patients were compared to those of 16 age-matched controls. RESULTS: Over the 12-month study period, polynomial modelling analyses identified 179 and 4 statistically significant transcripts with altered expression profiles (FDR < 0.05) between cases and controls in CD4+ and CD8+ populations, respectively. In CD8+ cells, two transcripts remained differentially expressed after 12 months; SGTB, associated with neuronal apoptosis, and FCGR3A, associatied with Takayasu arteritis. We detected genes that correlate with both symptoms and biochemical markers used for predicting long-term prognosis. 15 genes were shared across 3 phenotypes in CD4 and 16 across CD8 cells. In CD8, IL32 was common to 5 phenotypes including Polymyalgia Rheumatica, bilateral blindness and death within 12 months. CONCLUSIONS: This is the first longitudinal gene expression study undertaken to identify robust transcriptomic biomarkers of GCA. Our results show cell type-specific transcript expression profiles, novel gene-phenotype associations, and uncover important biological pathways for this disease. In the acute phase, the gene-phenotype relationships we have identified could provide insight to potential disease severity and as such guide in initiating appropriate patient management.

Geo-epidemiology of temporal artery biopsy-positive giant cell arteritis in Australia and New Zealand: is there a seasonal influence?

OBJECTIVE: Previous studies, although inconclusive, have suggested possible associations of environmental risk factors with the development of giant cell arteritis (GCA). We aim to investigate seasonal influence on the incidence of GCA across Australia and New Zealand. METHODS: In establishing an international study to investigate the molecular aetiology of GCA, archived temporal artery biopsy (TAB) specimens primarily from Australia and New Zealand were obtained. Demographic details including age, sex and date of TAB were collected from collaborating pathology departments. The season in which GCA was diagnosed was determined and compared with previous reports investigating the association between environmental risk factors and GCA. RESULTS: Our study comprises data from 2224 TAB-positive patients with GCA; 2099 of which were from patients in Australia and New Zealand. The mean age at time of diagnosis was 76.4 years of age. The female-to-male ratio was 2.2:1. We noted equal distribution of the incidence rate across all four seasons (530-580 cases diagnosed every quarter). Statistical analysis of seasonal variation by Poisson regression and cosinor methods showed no incidence preponderance across seasons. Our results do not support a seasonal component contributing to the onset of disease. Our literature search identifies no consistent environmental risk factor in association with GCA. CONCLUSION: This is the largest GCA data set reported outside of Europe. Our results demonstrate equal distribution of the incidence rate across all four seasons. In contrast to some earlier reports, we did not identify evidence of a seasonal component contributing to the onset of disease.

Mitochondrial replacement in an iPSC model of Leber's hereditary optic neuropathy.

Cybrid technology was used to replace Leber hereditary optic neuropathy (LHON) causing mitochondrial DNA (mtDNA) mutations from patient-specific fibroblasts with wildtype mtDNA, and mutation-free induced pluripotent stem cells (iPSCs) were generated subsequently. Retinal ganglion cell (RGC) differentiation demonstrates increased cell death in LHON-RGCs and can be rescued in cybrid corrected RGCs.

Development of a Modular Automated System for Maintenance and Differentiation of Adherent Human Pluripotent Stem Cells.

Patient-specific induced pluripotent stem cells (iPSCs) have tremendous potential for development of regenerative medicine, disease modeling, and drug discovery. However, the processes of reprogramming, maintenance, and differentiation are labor intensive and subject to intertechnician variability. To address these issues, we established and optimized protocols to allow for the automated maintenance of reprogrammed somatic cells into iPSCs to enable the large-scale culture and passaging of human pluripotent stem cells (PSCs) using a customized TECAN Freedom EVO. Generation of iPSCs was performed offline by nucleofection followed by selection of TRA-1-60-positive cells using a Miltenyi MultiMACS24 Separator. Pluripotency markers were assessed to confirm pluripotency of the generated iPSCs. Passaging was performed using an enzyme-free dissociation method. Proof of concept of differentiation was obtained by differentiating human PSCs into cells of the retinal lineage. Key advantages of this automated approach are the ability to increase sample size, reduce variability during reprogramming or differentiation, and enable medium- to high-throughput analysis of human PSCs and derivatives. These techniques will become increasingly important with the emergence of clinical trials using stem cells.

Heterogeneity of Human Research Ethics Committees and Research Governance Offices across Australia: An observational study.

BACKGROUND: Conducting ethically grounded research is a fundamental facet of all investigations. Nevertheless, the administrative burdens of current ethics review are substantial, and calls have been made for a reduction in research waste. AIMS: To describe the heterogeneity in administration and documentation required by Human Research Ethics Committees (HRECs) and Research Governance Offices (RGOs) across Australia. METHODS: In establishing a nationwide study to investigate the molecular aetiology of Giant Cell Arteritis (GCA), for which archived pathological specimens from around Australia are being recruited, we identified variation across separate HREC and RGO requirements. Submission paperwork and correspondence from each collaborating site and its representative office for research were reviewed. This data was interrogated to evaluate differences in current guidelines. RESULTS: Twenty-five pathology departments across seven Australian States collaborated in this study. All states, except Victoria, employed a single ethics review model. There was discrepancy amongst HRECs as to which application process applied to our study: seven requested completion of a "National Ethics Application Form" and three a "Low Negligible Risk" form. Noticeable differences in guidelines included whether electronic submission was sufficient. There was variability in the total number of documents submitted (range five to 22) and panel review turnaround time (range nine to 136 days). CONCLUSION: We demonstrate the challenges and illustrate the heavy workload involved in receiving widespread ethics and governance approval across Australia. We highlight the need to simplify, homogenise, and nationalise human ethics for non-clinical trial studies. Reducing unnecessary administration will enable investigators to achieve research aims more efficiently.

Child-led enquiry in primary science.

This research describes and evaluates the application of a child-led approach to scientific enquiry (the Community of Scientific Enquiry, CoSE) to children aged 8-11 (Key Stage 2) in Northern Ireland. Primary teachers were introduced to CoSE at a workshop and asked to evaluate its implementation with their class. Results from children (n = 364) and teachers (n = 19) found that CoSE engaged children with their science learning, and also developed confidence and oracy. However, teachers require more experience developing facilitation skills and in fitting science into a thematic teaching unit.

The role of anxiolytic premedication in reducing preoperative anxiety.

Prevention of preoperative anxiety with anxiolytic premedication is associated with improved preoperative outcomes in surgical patients. The objective of the authors' study was to evaluate the percentage of surgical patients that are prescribed premedication for preoperative anxiety before their anticipated surgical procedure. A prospective study was carried out by theatre nursing staff in the theatre reception bay of a university teaching hospital. A questionnaire was designed to record the number of patients that described symptoms consistent with preoperative anxiety. The number of patients that had been offered anxiolytic premedication for preoperative anxiety was also recorded. Consent was obtained from 115 consecutive surgical patients (male, n=52; female, n=63). Of these, 66% (n=76) reported anxiety before their surgical procedure (male: n=27, female: n=49). Premedication with a low-dose benzodiazepine was prescribed by an anaesthetist in 4% of cases (n=5). Patients that received premedication preoperatively reported effective relief of their anxiety symptoms This study demonstrates that preoperative patient anxiety is highly prevalent. The authors' findings suggest that premedication with anxiolytic pharmacological therapy may be an underused therapeutic resource for managing preoperative patient anxiety.

Natural history of hearing deterioration in intracanalicular vestibular schwannoma.

BACKGROUND: Intracanalicular vestibular schwannomas have a range of treatment options that can preserve hearing: microsurgery, stereotactic radiotherapy, and conservative observation. OBJECTIVE: To evaluate the natural course of hearing deterioration during a period of conservative observation. METHODS: A retrospective case review was performed on 47 patients with a unilateral intracanalicular vestibular schwannoma. Evaluation of growth was monitored by repeat MRI scanning. Repeated pure-tone and speech audiometry results were evaluated for subgroups of patients showing growth or no growth and by subsite location of tumor in the internal auditory canal. RESULTS: Patients had a mean follow-up of 3.6 years. Over the entire population, the pure-tone average thresholds at 0.5, 1, 2, and 3 kHz and the word recognition scores both significantly deteriorated from 38 to 51 dB HL, and from 66% to 55%, respectively. Overall, 74% of subjects with good hearing, according to the 50/50 rule, maintained hearing above this rule. There were no significant differences in hearing loss by subsite in the internal auditory canal (porus, fundus, central) or by growth status (stable, growing, shrinking). Only 6 patients showed a large hearing change. This happened early during follow-up, with relatively stable hearing after this. CONCLUSION: Hearing will deteriorate in some intracanalicular vestibular schwannomas, regardless of tumor growth. Hearing deterioration, if on a large scale, most likely occurs early in follow-up. The present results using conservative management in these tumors appear similar to those reported for stereotactic radiotherapy or microsurgery.

What is a good death? Stories from palliative care.

The components of good and bad deaths have not been well elucidated in the literature. Furthermore, the value of using narratives in palliative care research has not been extensively explored. We invited people involved in palliative care (patients, caregivers, physicians, and nurses) to tell us their stories of good and bad deaths, and 15 responded. We asked them to tell us about the good and bad deaths that they had witnessed and to describe what a good death and a bad death would be like for them, personally. Several common themes emerged from their good death narratives: a death free from pain, the sense of a life well lived, and a sense of community. Common bad death themes included a painful death and a loss of control and independence. We found that the use of story in palliative care provided an opportunity to create meaning and to heal for both the teller and the listener.

Neurofibromatosis 2--a family journey.

Neurofibromatosis 2 (NF2) is a complex autosomal dominant genetic disorder, now recognized to occur as a result of a mutation on chromosome 22. It is estimated to affect one in every 40,000 individuals worldwide. NF2's clinical manifestations of bilateral vestibular schwannomas and multiple other nervous system tumours have far-reaching implications for patients and families diagnosed with this challenging disorder. Management of these families should occur at specialty centres with the ability to provide treatment of these tumours, if necessary, as well as to have access to genetic testing and counselling. Decisions should be made with the quality of life of each individual as the cornerstone of care: knowing when to and when not to intervene is essential. The Atlantic Lateral Skull Base Clinic in Halifax follows approximately 400 patients with unilateral vestibular schwannomas and other skull base lesions. Twelve NF2 families are followed in this clinic. Several of their amazing stories will be shared in this presentation. Much can be done to effectively manage NF2 and help patients and families live healthy, happy and productive lives.

Exposure to "The Troubles" in Northern Ireland influences the clinical presentation of schizophrenia.

INTRODUCTION: This study investigates the effect of exposure to "The Troubles" (the period of civil unrest from 1968 onwards) in Northern Ireland on symptomatology in people with schizophrenia. METHOD: Eighty-two participants were assessed on a number of psychiatric rating scales and on measures of trauma, including an instrument designed to assess exposure to "Troubles"-related trauma. RESULTS: People with schizophrenia and a history of exposure to "The Troubles" had significantly higher levels of anxiety, depression, dissociative symptoms and number of admissions compared to those patients with no such exposure. DISCUSSION: "Troubles"-related trauma has a direct effect on the presentation of schizophrenia in Northern Ireland. Specific therapeutic intervention may be required in order to help patients come to terms with their experiences.

Vestibular schwannoma: how much residual hearing is useful?

OBJECTIVE: The objective of this study was to determine the usefulness of residual hearing in the tumour ear in vestibular schwannoma patients. DESIGN: A prospective case series study. SETTING: The study was performed at the Queen Elizabeth Health Sciences Centre in Halifax, Nova Scotia. METHODS: Thirty-three vestibular schwannoma patients and 13 controls underwent QuickSIN (Etymotic Research Inc, Elk Grove, IL) speech-in-noise testing with the tumour and good ears open and occluded. Nine testing conditions used three speakers with speech signal from the tumour side, the front, and the good ear side, with noise in other speakers. MAIN OUTCOME MEASURES: Tumour ear contribution (TEC) was calculated by the decrease in score with the index ear occluded. Multiple regression analysis and correlation coefficients were used to determine predictors of TEC. RESULTS: The strongest correlation was between the pure-tone average (PTA) and the TEC with signal from the tumour side. The speech discrimination score (SDS) was also significantly correlated with TEC in this condition. Neither PTA nor SDS correlated well with TEC with signal from other directions. Multiple regression analysis with TEC and sound from the tumour ear as the dependent variable showed that the SDS and PTA of the tumour ear are significant independent predictors (p = .049 and .037, respectively). There are no obvious breakpoints in the PTA or SDS to make 50%, 50 dB, or other operating points "special." CONCLUSION: The main contribution of residual hearing is in signals from the tumour side. The various rules are more or less equivalent in discriminating between those who will have a high TEC and those who will not.

The state tobacco settlement: where do we stand?

This paper reviews the history of the 1998 Master Tobacco Settlement and updates readers on the states' use of the resultant monetary windfall for tobacco prevention and cessation activities. It further defines mechanisms for otorhinolaryngology (ORL) nurses' political and social activism regarding tobacco issues.