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https://www.readbyqxmd.com/read/28219732/all-trans-retinal-levels-and-formation-of-lipofuscin-precursors-after-bleaching-in-rod-photoreceptors-from-wild-type-and-abca4-mice
#1
Leopold Adler, Chunhe Chen, Yiannis Koutalos
The accumulation of lipofuscin in the cells of the retinal pigment epithelium (RPE) is thought to play an important role in the development and progression of degenerative diseases of the retina. The bulk of RPE lipofuscin originates in reactions of the rhodopsin chromophore, retinal, with components of the photoreceptor outer segment. The 11-cis retinal isomer is generated in the RPE and supplied to rod photoreceptor outer segments where it is incorporated as the chromophore of rhodopsin. It is photoisomerized during light detection to all-trans and subsequently released by photoactivated rhodopsin as all-trans retinal, which is removed through reduction to all-trans retinol in a reaction requiring metabolic input in the form of NADPH...
February 17, 2017: Experimental Eye Research
https://www.readbyqxmd.com/read/28192797/aberrant-buildup-of-all-trans-retinal-dimer-a-nonpyridinium-bisretinoid-lipofuscin-fluorophore-contributes-to-the-degeneration-of-the-retinal-pigment-epithelium
#2
Junli Zhao, Yi Liao, Jingmeng Chen, Xinran Dong, Zhan Gao, Houjian Zhang, Xiaodan Wu, Zuguo Liu, Yalin Wu
Purpose: Nondegradable fluorophores that accumulate as deleterious lipofuscin of RPE are involved in pathological mechanisms leading to the degeneration of RPE in AMD. A2E, a major component of RPE lipofuscin, could cause damage to RPE cells. Nevertheless, all-trans-retinal dimer (atRAL dimer) was found to be much more abundant than that of A2E in eyes of Abca4-/-Rdh8-/- double-knockout (DKO) mice, a rodent model showing the typical characteristics of retinopathies in AMD patients. Our aim was to elucidate the effect and mechanism of atRAL dimer-induced RPE degeneration...
February 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28149006/role-of-lipids-in-retinal-vascular-and-macular-disorders
#3
REVIEW
Gunjan Prakash, Rachit Agrawal, Tanie Natung
Retinal diseases are significant by increasing problem in every part of the world. While excellent treatment has emerged for various retinal diseases, treatment for early disease is lacking due to an incomplete understanding of all molecular events. With aging, there is a striking accumulation of neutral lipids in Bruch's membrane. These neutral lipids leads to the creation of a lipid wall at the same locations where drusen and basal linear deposit, pathognomonic lesions of Age-related macular degeneration, subsequently form...
March 2017: Indian Journal of Clinical Biochemistry: IJCB
https://www.readbyqxmd.com/read/28147405/prominent-optic-disc-featured-in-inherited-retinopathy
#4
M G Todorova, R I Bojinova, C Valmaggia, D F Schorderet
Background We investigated the relationship between prominent optic disc (POD) and inherited retinal dystrophy (IRD). Patients and Methods A cross-sectional consecutive study was performed in 10 children and 11 adults of 7 non-related families. We performed clinical phenotyping, including a detailed examination, fundus autofluorescence, and colour fundus and OCT imaging. Genetic testing was subsequently performed for all family members presenting retinal pathology. Results In 4 members of a 3-generation family, hyperfluorescent deposits on the surface of POD were related to a p...
February 1, 2017: Klinische Monatsblätter Für Augenheilkunde
https://www.readbyqxmd.com/read/28130426/genetic-analysis-of-ten-pedigrees-with-inherited-retinal-degeneration-ird-by-exome-sequencing-and-phenotype-genotype-association
#5
Pooja Biswas, Jacque L Duncan, Bruno Maranhao, Igor Kozak, Kari Branham, Luis Gabriel, Jonathan H Lin, Guilio Barteselli, Mili Navani, John J Suk, Michelle Parke, Catherine Schlechter, Richard Weleber, John R Heckenlively, Gislin Dagnelie, Pauline Lee, S Amer Riazuddin, Radha Ayyagari
PURPOSE: To identify causative mutations and characterize the phenotype associated with the genotype in ten unrelated families with autosomal recessive retinal degeneration. METHODS: Ophthalmic evaluation and DNA isolation was carried out in 10 pedigrees with IRD. Exomes of probands from 8 pedigrees were captured using Nimblegen V2/V3 or Agilent V5+UTR kits, and sequencing was performed on Illumina HiSeq. The DHDDS gene was screened for mutations in the remaining two pedigrees with Ashkenazi Jews ancestry...
January 27, 2017: Physiological Genomics
https://www.readbyqxmd.com/read/28118664/mutation-spectrum-of-the-abca4-gene-in-335-stargardt-disease-patients-from-a-multicenter-german-cohort-impact-of-selected-deep-intronic-variants-and-common-snps
#6
Heidi L Schulz, Felix Grassmann, Ulrich Kellner, Georg Spital, Klaus Rüther, Herbert Jägle, Karsten Hufendiek, Philipp Rating, Cord Huchzermeyer, Maria J Baier, Bernhard H F Weber, Heidi Stöhr
Purpose: Stargardt disease (STGD1) is an autosomal recessive retinopathy, caused by mutations in the retina-specific ATP-binding cassette transporter (ABCA4) gene. To establish the mutational spectrum and to assess effects of selected deep intronic and common genetic variants on disease, we performed a comprehensive sequence analysis in a large cohort of German STGD1 patients. Methods: DNA samples of 335 STGD1 patients were analyzed for ABCA4 mutations in its 50 coding exons and adjacent intronic sequences by resequencing array technology or next generation sequencing (NGS)...
January 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28095140/prom1-gene-variations-in-brazilian-patients-with-macular-dystrophy
#7
Mariana Vallim Salles, Fabiana Louise Motta, Elton Dias da Silva, Patricia Varela Lima Teixeira, Kárita Antunes Costa, Rafael Filippelli-Silva, Renan Martin, João Bosco Pesquero, Juliana Maria Ferraz Sallum
BACKGROUND: Although the pathogenicity of the prominin-1 (PROM1) gene has already been described as associated with autosomal dominant Stargardt disease, little is known about sequence variations in this gene. PURPOSE: The aim of this study was to evaluate PROM1 gene sequence variations in patients with macular dystrophy. MATERIAL AND METHODS: This retrospective study evaluated variations in the PROM1 gene detected by next-generation sequencing test in patients with macular dystrophy and Stargardt disease...
January 2017: Ophthalmic Genetics
https://www.readbyqxmd.com/read/28061825/new-cdh3-mutation-in-the-first-spanish-case-of-hypotrichosis-with-juvenile-macular-dystrophy-a-case-report
#8
Fiona Blanco-Kelly, Luciana Rodrigues-Jacy da Silva, Iker Sanchez-Navarro, Rosa Riveiro-Alvarez, Miguel Angel Lopez-Martinez, Marta Corton, Carmen Ayuso
BACKGROUND: CDH3 on 16q22.1 is responsible for two rare autosomal recessive disorders with hypotrichosis and progressive macular dystrophy: Hypotrichosis with Juvenile Macular Dystrophy and Ectodermal Dysplasia, Ectrodactyly and Macular Dystrophy. We present a new case of Hypotrichosis with Juvenile Macular Dystrophy. CASE PRESENTATION: A Spanish male born in 1998 from non-consanguineous healthy parents with a suspected diagnosis of Keratosis Follicularis Spinulosa Decalvans and Retinitis Pigmentosa Inversa referred to our Genetics Department (IIS-Fundación Jiménez Díaz)...
January 7, 2017: BMC Medical Genetics
https://www.readbyqxmd.com/read/28044389/in-silico-functional-meta-analysis-of-5-962-abca4-variants-in-3-928-retinal-dystrophy-cases
#9
Stéphanie S Cornelis, Nathalie M Bax, Jana Zernant, Rando Allikmets, Lars G Fritsche, Johan T den Dunnen, Muhammad Ajmal, Carel B Hoyng, Frans P M Cremers
Variants in the ABCA4 gene are associated with a spectrum of inherited retinal diseases (IRDs), most prominently with autosomal recessive (ar) Stargardt disease (STGD1) and ar cone-rod dystrophy. The clinical outcome to a large degree depends on the severity of the variants. To provide an accurate prognosis and to select patients for novel treatments, functional significance assessment of nontruncating ABCA4 variants is important. We collected all published ABCA4 variants from 3,928 retinal dystrophy cases in a Leiden Open Variation Database, and compared their frequency in 3,270 Caucasian IRD cases with 33,370 non-Finnish European control individuals...
January 3, 2017: Human Mutation
https://www.readbyqxmd.com/read/28035529/hereditary-retinal-dystrophy
#10
Thomas C Hohman
As our understanding of the genetic basis for inherited retinal disease has expanded, gene therapy has advanced into clinical development. When the gene mutations associated with inherited retinal dystrophies were identified, it became possible to create animal models in which individual gene were altered to match the human mutations. The retina of these animals were then characterized to assess whether the mutated genes produced retinal phenotypes characteristic of disease-affected patients. Following the identification of a subpopulation of patients with the affected gene and the development of techniques for the viral gene transduction of retinal cells, it has become possible to deliver a copy of the normal gene into the retinal sites of the mutated genes...
December 30, 2016: Handbook of Experimental Pharmacology
https://www.readbyqxmd.com/read/28005406/a-report-on-molecular-diagnostic-testing-for-inherited-retinal-dystrophies-by-targeted-genetic-analyses
#11
Hema L Ramkumar, Harini V Gudiseva, Kameron T Kishaba, John J Suk, Rohan Verma, Keerti Tadimeti, John A Thorson, Radha Ayyagari
AIM: To test the utility of targeted sequencing as a method of clinical molecular testing in patients diagnosed with inherited retinal degeneration (IRD). METHODS: After genetic counseling, peripheral blood was drawn from 188 probands and 36 carriers of IRD. Single gene testing was performed on each patient in a Clinical Laboratory Improvement Amendment (CLIA) certified laboratory. DNA was isolated, and all exons in the gene of interest were analyzed along with 20 base pairs of flanking intronic sequence...
February 2017: Genetic Testing and Molecular Biomarkers
https://www.readbyqxmd.com/read/28002570/asymmetric-inter-eye-progression-in-stargardt-disease
#12
Stanley Lambertus, Nathalie M Bax, Joannes M M Groenewoud, Frans P M Cremers, Gert Jan van der Wilt, B Jeroen Klevering, Thomas Theelen, Carel B Hoyng
Purpose: Asymmetry in disease progression between left and right eyes can occur in Stargardt disease (STGD1), and this needs to be considered in novel therapeutic trials with a fellow-eye paired controlled design. This study investigated the inter-eye discordance of best-corrected visual acuity (BCVA) and progression of RPE atrophy in STGD1. Methods: We performed a retrospective cohort study collecting 68 STGD1 patients (136 eyes) with ≥1 ABCA4 variants and ≥0...
December 1, 2016: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/27992460/norbixin-protects-retinal-pigmented-epithelium-cells-and-photoreceptors-against-a2e-mediated-phototoxicity-in-vitro-and-in-vivo
#13
Valérie Fontaine, Elodie Monteiro, Elena Brazhnikova, Laëtitia Lesage, Christine Balducci, Louis Guibout, Laurence Feraille, Pierre-Paul Elena, José-Alain Sahel, Stanislas Veillet, René Lafont
The accumulation of N-retinylidene-N-retinylethanolamine (A2E, a toxic by-product of the visual pigment cycle) in the retinal pigment epithelium (RPE) is a major cause of visual impairment in the elderly. Photooxidation of A2E results in retinal pigment epithelium degeneration followed by that of associated photoreceptors. Present treatments rely on nutrient supplementation with antioxidants. 9'-cis-Norbixin (a natural diapocarotenoid, 97% purity) was prepared from Bixa orellana seeds. It was first evaluated in primary cultures of porcine retinal pigment epithelium cells challenged with A2E and illuminated with blue light, and it provided an improved photo-protection as compared with lutein or zeaxanthin...
2016: PloS One
https://www.readbyqxmd.com/read/27939946/stargardt-disease-associated-mutation-spectrum-of-a-russian-federation-cohort
#14
Inna V Zolnikova, Vladimir V Strelnikov, Natalia A Skvortsova, Alexander S Tanas, Debmalya Barh, Elena V Rogatina, Irina V Egorova, Darja V Levina, Olga N Demenkova, Egor G Prikaziuk, Marianna E Ivanova
ABCA4-associated mutation screening is extensively performed in European, African, American and several other populations for various retinopathies. However, it has not been well studied in a Russian cohort. Using next-generation (325 genes inherited disease panel) and Sanger sequencing technologies for the first time we documented the spectrum of genetic variations in a Russian retinopathy cohort of 51 patients from 10 ethnic groups. We found ABCA4 variations in 70.5% cases and one case with BEST1 variation...
February 2017: European Journal of Medical Genetics
https://www.readbyqxmd.com/read/27898983/molecular-diagnosis-of-inherited-retinal-diseases-in-indigenous-african-populations-by-whole-exome-sequencing
#15
Lisa Roberts, Rinki Ratnapriya, Morné du Plessis, Vijender Chaitankar, Raj S Ramesar, Anand Swaroop
Purpose: A majority of genes associated with inherited retinal diseases (IRDs) have been identified in patients of European origin. Indigenous African populations exhibit rich genomic diversity, and evaluation of reported genetic mutations has yielded low returns so far. Our goal was to perform whole-exome sequencing (WES) to examine variants in known IRD genes in underrepresented African cohorts. Methods: Whole-exome sequencing was performed on 56 samples from 16 families with diverse IRD phenotypes that had remained undiagnosed after screening for known mutations using genotyping-based microarrays (Asper Ophthalmics)...
November 1, 2016: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/27874104/identifying-mutations-in-tunisian-families-with-retinal-dystrophy
#16
Imen Habibi, Ahmed Chebil, Yosra Falfoul, Nathalie Allaman-Pillet, Fedra Kort, Daniel F Schorderet, Leila El Matri
Retinal dystrophies (RD) are a rare genetic disorder with high genetic heterogeneity. This study aimed at identifying disease-causing variants in fifteen consanguineous Tunisian families. Full ophthalmic examination was performed. Index patients were subjected to IROme analysis or whole exome sequencing followed by homozygosity mapping. All detected variations were confirmed by direct Sanger sequencing. Mutation analysis in our patients revealed two compound heterozygous mutations p.(R91W);(V172D) in RPE65, and five novel homozygous mutations: p...
November 22, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27820952/the-effect-on-retinal-structure-and-function-of-15-specific-abca4-mutations-a-detailed-examination-of-82-hemizygous-patients
#17
Ana Fakin, Anthony G Robson, John Pei-Wen Chiang, Kaoru Fujinami, Anthony T Moore, Michel Michaelides, Graham E Holder, Andrew R Webster
Purpose: To determine the effect of 15 individual ABCA4 mutations on disease severity. Methods: Eighty-two patients harboring 15 distinct ABCA4 mutations in trans with null (hemizygous), 10 homozygous, and 20 nullizygous patients were recruited. Age of onset was determined from medical histories. Electroretinography (ERG) responses were classified into three groups (normal; cone dysfunction; cone and rod dysfunction). The dark-adapted bright-flash (DA 10.0) a-wave amplitudes and the light-adapted flicker ERG (LA 3...
November 1, 2016: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/27820873/increased-plasma-cgmp-in-a-family-with-autosomal-recessive-retinitis-pigmentosa-due-to-homozygous-mutations-in-the-pde6a-gene
#18
Ulrika Kjellström, Patricia Veiga-Crespo, Sten Andréasson, Per Ekström
Purpose: To describe genotype and phenotype in a family with autosomal recessive retinitis pigmentosa (arRP) carrying homozygous mutations in the gene for the α-subunit of cyclic guanosine monophosphate (cGMP)-hydrolyzing phosphodiesterase 6 (PDE6A). Moreover, to compare their plasma cGMP levels to controls, exploring the possible role for cGMP in RP diagnostics. Methods: Seven siblings and their parents were recruited. Microarray, verified by Sanger sequencing, was used for genotyping...
November 1, 2016: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/27775217/the-intronic-abca4-c-5461-10t-c-variant-frequently-seen-in-patients-with-stargardt-disease-causes-splice-defects-and-reduced-abca4-protein-level
#19
Ingvild Aukrust, Ragnhild W Jansson, Cecilie Bredrup, Hilde E Rusaas, Siren Berland, Agnete Jørgensen, Marte G Haug, Eyvind Rødahl, Gunnar Houge, Per M Knappskog
PURPOSE: Despite being the third most common ABCA4 variant observed in patients with Stargardt disease, the functional effect of the intronic ABCA4 variant c.5461-10T>C is unknown. The purpose of this study was to investigate the molecular effect of this variant. METHODS: Fibroblast samples from patients carrying the ABCA4 variant c.5461-10T>C were analysed by isolating total RNA, followed by real-time polymerase chain reaction (RT-PCR) using specific primers spanning the variant...
October 24, 2016: Acta Ophthalmologica
https://www.readbyqxmd.com/read/27753762/clinical-progress-in-inherited-retinal-degenerations-gene-therapy-clinical-trials-and-advances-in-genetic-sequencing
#20
Brian P Hafler
PURPOSE: Inherited retinal dystrophies are a significant cause of vision loss and are characterized by the loss of photoreceptors and the retinal pigment epithelium (RPE). Mutations in approximately 250 genes cause inherited retinal degenerations with a high degree of genetic heterogeneity. New techniques in next-generation sequencing are allowing the comprehensive analysis of all retinal disease genes thus changing the approach to the molecular diagnosis of inherited retinal dystrophies...
October 6, 2016: Retina
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