124 research outputs found
Whole exome sequencing implicates eye development, the unfolded protein response and plasma membrane homeostasis in primary open-angle glaucoma
No full textPurpose: To identify biological processes associated with POAG and its subtypes, high-tension (HTG) and normal-tension glaucoma (NTG), by analyzing rare potentially damaging genetic variants. Methods: A total of 122 and 65 unrelated HTG and NTG participants, respectively, with early onset advanced POAG, 103 non-glaucoma controls and 993 unscreened ethnicity-matched controls were included in this study. Study participants without myocilin disease-causing variants and non-glaucoma controls were subjected to whole exome sequencing on an Illumina HiSeq2000. Exomes of participants were sequenced on an Illumina HiSeq2000. Qualifying variants were rare in the general population (MAF < 0.001) and potentially functionally damaging (nonsense, frameshift, splice or predicted pathogenic using SIFT or Polyphen2 software). Genes showing enrichment of qualifying variants in cases were selected for pathway and network analysis using InnateDB. Results: POAG cases showed enrichment of rare variants in camera-type eye development genes (p = 1.40×10–7, corrected p = 3.28×10–4). Implicated eye development genes were related to neuronal or retinal development. HTG cases were significantly enriched for key regulators in the unfolded protein response (UPR) (p = 7.72×10–5, corrected p = 0.013). The UPR is known to be involved in myocilin-related glaucoma; our results suggest the UPR has a role in non-myocilin causes of HTG. NTG cases showed enrichment in ion channel transport processes (p = 1.05×10–4, corrected p = 0.027) including calcium, chloride and phospholipid transporters involved in plasma membrane homeostasis. Network analysis also revealed enrichment of the MHC Class I antigen presentation pathway in HTG, and the EGFR1 and cell-cycle pathways in both HTG and NTG. Conclusion: This study suggests that mutations in eye development genes are enriched in POAG. HTG can result from aberrant responses to protein misfolding which may be amenable to molecular chaperone therapy. NTG is associated with impaired plasma membrane homeostasis increasing susceptibility to apoptosis.Tiger Zhou, Emmanuelle Souzeau, Shiwani Sharma, John Landers, Richard Mills, Ivan Goldberg, Paul R. Healey, Stuart Graham, Alex W. Hewitt, David A. Mackey, Anna Galanopoulos, Robert J. Casson, Jonathan B. Ruddle, Jonathan Ellis, Paul Leo, Matthew A. Brown, Stuart MacGregor, David J. Lynn, Kathryn P. Burdon, Jamie E. Crai
Genome-wide association study of intraocular pressure uncovers new pathways to glaucoma
No full textPublished online: 27 July 2018Intraocular pressure (IOP) is currently the sole modifiable risk factor for primary open-angle glaucoma (POAG), one of the leading causes of blindness worldwide1. Both IOP and POAG are highly heritable2. We report a combined analysis of participants from the UK Biobank (n = 103,914) and previously published data from the International Glaucoma Genetic Consortium (n = 29,578)3,4 that identified 101 statistically independent genome-wide-significant SNPs for IOP, 85 of which have not been previously reported4-12. We examined these SNPs in 11,018 glaucoma cases and 126,069 controls, and 53 SNPs showed evidence of association. Gene-based tests implicated an additional 22 independent genes associated with IOP. We derived an allele score based on the IOP loci and loci influencing optic nerve head morphology. In 1,734 people with advanced glaucoma and 2,938 controls, participants in the top decile of the allele score were at increased risk (odds ratio (OR) = 5.6; 95% confidence interval (CI): 4.1-7.6) of glaucoma relative to the bottom decile.Stuart MacGregor, Jue-Sheng Ong, Jiyuan An, Xikun Han, Tiger Zhou, Owen M. Siggs, Matthew H. Law, Emmanuelle Souzeau, Shiwani Sharma, David J. Lynn, Jonathan Beesley, Bronwyn Sheldrick, Richard A. Mills, John Landers, Jonathan B. Ruddle, Stuart L. Graham, Paul R. Healey, Andrew J. R. White, Robert J. Casson, Stephen Best, John R Grigg, Ivan Goldberg, Joseph E. Powell, David C. Whiteman, Graham L. Radford-Smith, Nicholas G. Martin, Grant W. Montgomery, Kathryn P. Burdon, David A. Mackey, Puya Gharahkhani, Jamie E. Craig and Alex W. Hewit
A geometric morphometric assessment of the optic cup in glaucoma
No full textThe morphologic appearance of the optic disc is of interest in glaucoma. In contrast to descriptive classification systems that are currently used, a quantitative approach to the analysis of optic disc morphology is required. Our goal was to determine the optimal method for quantifying optic cup shape by comparing traditional (ovality, form-factor and neuroretinal rim (NRR) width ratio) and geometric morphometric approaches. Left optic disc stereophotographs of 160 (80 normal and 80 glaucomatous (stratified by severity)) subjects were examined. The optic cup margins were stereoscopically delineated with a custom tracing system and saved as a series of discrete points. The geometric morphometric methods of elliptic Fourier analysis (EFA) and sliding semi-landmark analysis (SSLA) were used to eliminate variation unrelated to shape (e.g. size) and yield a series of shape variables. Differences in optic cup shape between normal and glaucoma groups were investigated. Discriminant functions were computed and the sensitivity and specificity of each technique determined. Receiver operator characteristic (ROC) curves were calculated for all methods and evaluated in their potential to discriminate between normal and glaucomatous eyes based on the shape variables. All geometric morphometric methods revealed differences between normal and glaucomatous eyes in optic cup shape, in addition to the traditional parameters of ovality, form-factor and NRR width ratio (p<0.0005). SSLA (minimum bending energy criterion - 18 points) had the best sensitivity (83%) and area under the curve (AUC) (0.91). EFA (72 points) performed similarly well (74%, 0.89) as did the set of traditional shape-based variables (76%, 0.86). This study demonstrated that a geometric morphometric approach for discriminating between normal and glaucomatous eyes in optic cup shape is superior to that provided by traditional single parameter shape measures. Such analytical techniques could be incorporated into future automated optic disc screening modalities. (C) 2010 Elsevier Ltd. All rights reserved
Human TUBB3 mutations perturb microtubule dynamics, kinesin interactions, and axon guidance
No full textWe report that eight heterozygous missense mutations in TUBB3, encoding the neuron-specific beta-tubulin isotype III, result in a spectrum of human nervous system disorders that we now call the TUBB3 syndromes. Each mutation causes the ocular motility disorder CFEOM3, whereas some also result in intellectual and behavioral impairments, facial paralysis, and/or later-onset axonal sensorimotor polyneuropathy. Neuroimaging reveals a spectrum of abnormalities including hypoplasia of oculomotor nerves and dysgenesis of the corpus callosum, anterior commissure, and corticospinal tracts. A knock-in disease mouse model reveals axon guidance defects without evidence of cortical cell migration abnormalities. We show that the disease-associated mutations can impair tubulin heterodimer formation in vitro, although folded mutant heterodimers can still polymerize into microtubules. Modeling each mutation in yeast tubulin demonstrates that all alter dynamic instability whereas a subset disrupts the interaction of microtubules with kinesin motors. These findings demonstrate that normal TUBB3 is required for axon guidance and maintenance in mammals.Max A. Tischfield, Hagit N. Baris, Chen Wu, Guenther Rudolph, Lionel Van Maldergem, Wei He, Wai-Man Chan, Caroline Andrews, Joseph L. Demer, Richard L. Robertson, David A. Mackey, Jonathan B. Ruddle, Thomas D. Bird, Irene Gottlob, Christina Pieh, Elias I. Traboulsi, Scott L. Pomeroy, David G. Hunter, Janet S. Soul, Anna Newlin, Louise J. Sabol, Edward J. Doherty, Clara E. de Uzca´ tegui, Nicolas de Uzca´ tegui, Mary Louise Z. Collins, Emin C. Sener, Bettina Wabbels, Heide Hellebrand, Thomas Meitinger, Teresa de Berardinis, Adriano Magli, Costantino Schiavi, Marco Pastore-Trossello, Feray Koc, Agnes M. Wong, Alex V. Levin, Michael T. Geraghty, Maria Descartes, Maree Flaherty, Robyn V. Jamieson, H.U. Møller, Ingo Meuthen, David F. Callen, Janet Kerwin, Susan Lindsay, Alfons Meindl, Mohan L. Gupta, Jr., David Pellman, and Elizabeth C. Engl
The phenotypic spectrum of ADAMTSL4-associated ectopia lentis: Additional cases, complications, and review of literature
No full textPrior presentation of manuscript data: Presented at the Royal Australian and New Zealand College of Ophthalmologists (RANZCO) 52nd Annual Scientific Congress 2022.
Published 4 September 2022Purpose: ADAMTSL4-associated ectopia lentis is a rare autosomal recessive condition that is primarily associated with crystalline lens displacement. However, the prevalence of other ocular and systemic manifestations of this condition is poorly understood. In this study, we summarize the ocular and systemic phenotypic spectrum of this condition. Methods: A cross-sectional case study series of four individuals with biallelic pathogenic or likely pathogenic ADAMTSL4 variants was performed alongside a literature review of individuals with ADAMTSL4-associated ectopia lentis on September 29, 2021. Ocular and systemic findings, complications, and genetic findings of all four individuals were collected and summarized. Results: The phenotypic spectrum across 91 individuals sourced from literature and four individuals from this case study series was highly variable. The main ocular phenotypes included ectopia lentis (95/95, 100%), ectopia lentis et pupillae (18/95, 19%), iris transillumination (13/95, 14%), iridodonesis (12/95, 13%), persistent pupillary membrane (12/95, 13%), and early-onset cataract or lens opacities (12/95, 13%). Anterior segment features other than ectopia lentis appeared to be exclusively associated with biallelic loss of function variants (p<0.001). Pupillary block glaucoma had a prevalence of 1%. Post-lensectomy complications included retinal detachment (6/41, 15%), elevated intraocular pressure (4/41, 10%), and aphakic glaucoma (1/41, 2%). Most individuals were not reported to have had systemic features (69/95, 73%). Conclusions: The clinical phenotype of ADAMTSL4-associated ectopia lentis was summarized and expanded. Clinicians should be aware of the varied ocular phenotype and the risks of retinal detachment, ocular hypertension, and glaucoma in the diagnosis and management of this condition.Lachlan S.W. Knight, Sean Mullany, Deepa A. Taranath, Jonathan B. Ruddle, Christopher P. Barnett, Suzanne C.E.H. Sallevelt, Ella C. Berry, Henry N. Marshall, Georgina L. Hollitt, Emmanuelle Souzeau, Jamie E. Craig, Owen M. Sigg
The Australian and New Zealand Registry of Advanced Glaucoma: methodology and recruitment
No full textBACKGROUND: Glaucoma is a sight threatening disease affecting 2-3% of the population over the age of 40. Glaucoma is treatable, and severe vision loss can usually be prevented if diagnosis is made at an early stage. Genetic factors play a major role in the pathogenesis of the condition, and therefore genetic testing to identify asymptomatic at risk individuals is a promising strategy to reduce the prevalence of glaucoma blindness. Furthermore, unravelling genetic risk factors for glaucoma would also allow a better understanding of the pathogenesis of the condition, and the development of new treatments. DESIGN: The Australian and New Zealand Registry of Advanced Glaucoma is a prospective study which aims to develop a large cohort of glaucoma cases with severe visual field loss to identify novel genetic risk factors for glaucoma blindness. METHODS: Clinical information and blood are collected from participants after referral by eye practitioners. Samples are collected across Australia and New Zealand using postage kits. PARTICIPANTS: Our registry has recruited just over 2000 participants with advanced glaucoma, as well as secondary and developmental glaucomas. RESULTS: A positive family history of glaucoma is present in more than half of the advanced glaucoma cases and the age at diagnosis is significantly younger for participants with affected relatives, which reinforces the involvement of genetic factors in glaucoma. CONCLUSIONS: With the collection of glaucoma cases recruited so far, our registry aims to identify novel glaucoma genetic risk factors to establish risk profiling of the population and protocols for genetic testing.Emmanuelle Souzeau, Ivan Goldberg, Paul R Healey, Richard AD Mills, John Landers, Stuart L Graham, John RB Grigg, Bronwyn Usher, Tania Straga, April Crawford, Robert J Casson, William H Morgan, Jonathan B Ruddle, Michael A Coote, Andrew White, James Stewart, Alex W Hewitt, David A Mackey, Kathryn P Burdon, Jamie E Crai
Letter to the Editor: Simultaneous presentation of hereditary hyperferritinaemia cataract syndrome and hereditary haemochromatosis
No full textThis article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving'. Copyright © 2018 Royal Australian and New Zealand College of Ophthalmologists
This author accepted manuscript is made available following 12 month embargo from date of publication (May 2018) in accordance with the publisher’s archiving policy"No abstract is available for this article"- Publishe
Glaucoma spectrum and age-related prevalence of individuals with FOXC1 and PITX2 variants
No full textPublished online 3 May 2017Variation in FOXC1 and PITX2 is associated with Axenfeld-Rieger syndrome, characterised by structural defects of the anterior chamber of the eye and a range of systemic features. Approximately half of all affected individuals will develop glaucoma, but the age at diagnosis and the phenotypic spectrum have not been well defined. As phenotypic heterogeneity is common, we aimed to delineate the age-related penetrance and the full phenotypic spectrum of glaucoma in FOXC1 or PITX2 carriers recruited through a national disease registry. All coding exons of FOXC1 and PITX2 were directly sequenced and multiplex ligation-dependent probe amplification was performed to detect copy number variation. The cohort included 53 individuals from 24 families with disease-associated FOXC1 or PITX2 variants, including one individual diagnosed with primary congenital glaucoma and five with primary open-angle glaucoma. The overall prevalence of glaucoma was 58.5% and was similar for both genes (53.3% for FOXC1 vs 60.9% for PITX2, P=0.59), however, the median age at glaucoma diagnosis was significantly lower in FOXC1 (6.0±13.0 years) compared with PITX2 carriers (18.0±10.6 years, P=0.04). The penetrance at 10 years old was significantly lower in PITX2 than FOXC1 carriers (13.0% vs 42.9%, P=0.03) but became comparable at 25 years old (71.4% vs 57.7%, P=0.38). These findings have important implications for the genetic counselling of families affected by Axenfeld-Rieger syndrome, and also suggest that FOXC1 and PITX2 contribute to the genetic architecture of primary glaucoma subtypes.Emmanuelle Souzeau, Owen M Siggs, Tiger Zhou, Anna Galanopoulos, Trevor Hodson, Deepa Taranath, Richard A Mills, John Landers, John Pater, James E Smith, James E Elder, Julian L Rait, Paul Giles, Vivek Phakey, Sandra E Staffieri, Lisa S Kearns, Andrew Dubowsky, David A Mackey, Alex W Hewitt, Jonathan B Ruddle, Kathryn P Burdon and Jamie E Crai
Primary congenital glaucoma due to paternal uniparental isodisomy of chromosome 2 and CYP1B1 deletion
No full text© 2019 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.
This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.Background: CYP1B1 variants and deletions are the most common cause of primary congenital glaucoma (PCG). Methods: We investigated an individual with PCG from the Australian and New Zealand Registry of Advanced Glaucoma. We performed sequencing of the CYP1B1 gene, followed by Multiplex Ligation-dependent Probe Amplification and SNP array. Results: We identified a homozygous deletion of the CYP1B1 gene by Multiplex Ligation-dependent Probe Amplification and confirmed that the father was heterozygous for a CYP1B1 deletion but the mother had normal gene copy number. SNP array identified paternal uniparental isodisomy of the entire chromosome 2. Conclusions: This study is the first report of a homozygous CYP1B1 whole gene deletion due to paternal uniparental isodisomy of chromosome 2 as a cause of PCG. These results illustrate the importance of genetic testing in providing appropriate genetic counseling regarding the risks of recurrence
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