Expanding the phenotypic and genotypic spectrum of Bietti crystalline dystrophy

Abstract: The rare form of retinal dystrophy, Bietti crystalline dystrophy, is associated with variations in CYP4V2, a member of the cytochrome P450 family. This study reports patients affected by typical and atypical Bietti crystalline dystrophy, expanding the spectrum of this disease. This is an observational case series of patients with a clinical and molecular diagnosis of Bietti crystalline dystrophy that underwent multimodal imaging. Four unrelated patients are described with two known variants, c.802‐8_810del17insGC and c.518T > G (p.Leu173Trp), and one novel missense variant, c.1169G > T (p.Arg390Leu). The patient with the novel homozygous variant had the most severe phenotype resulting in macular hole formation and retinal detachment in both eyes. To the best of our knowledge, there is no association of these features with Bietti crystalline dystrophy. Patient 1 was the youngest patient and had the mildest phenotype with crystals in the retina without chorioretinal atrophy and visual complaints. Patients 2 and 3 presented with fewer crystals and chorioretinal atrophy. These three patients presented a classic phenotype. The fourth patient presented with an atypical and severe phenotype. This study reveals a new genotype and new phenotype associated with this disorder. Keywords: bietti crystalline dystrophy; CYP4V2 protein; genetic testing; missense mutation; insertion‐deletion mutatio

Correlação Entre Fenótipo E Genótipo De Pacientes Com Doença De Stargardt

Purpose: To Identify Genetic Variants In Brazilian Patients With Clinical Diagnosis Of Stargardt Disease And To Correlate With Its Phenotypic Manifestation And Hereditary Characteristics. Methods: Patients With Clinical Diagnosis Of Stargardt Disease From Retina Clinic Of Unifesp Were Included. Medical Records From Patients From The Instituto De Genética Ocular, São Paulo " Brazil, Were Reviewed. The Abca4, Elovl4 And Prom1 Genes Were Analyzed By The Nextgeneration Sequencing (Ngs) And Complementation With The Sanger Sequencing. Results: 52 Patients From 47 Families Were Included. In The First Phase 24 Patients From 21 Families From Retina Clinic Of Unifesp Were Selected. In The Second Phase, 254 Medical Records From Instituto De Genética Ocular Were Reviewed. Of These, 28 Patients From 26 Families With Pathogenic Variants In The Abca4 And Prom1 Genes Detected By Ngs Were Selected. No Patient Had Genetic Alteration In The Elovl4 Gene. The Age Of The Patients Varied From 10 To 66 Years And The Age Of Onset OfObjetivo: Identificar As Variantes Genéticas Em Pacientes Com Diagnóstico Clínico De Doença De Stargardt E Correlacionar Com A Sua Manifestação Fenotípica E Características De Hereditariedade Na População Brasileira. Métodos: Foram Incluídos Pacientes Com Diagnóstico De Doença De Stargardt Que Fazem Acompanhamento No Ambulatório De Retina Da Universidade Federal De São Paulo " Unifesp Ou No Instituto De Genética Ocular (Igo), São Paulo-Brasil. Os Casos Oriundos Da Unifesp Foram Submetidos À Análise De Sequenciamento De Nova Geração (Ngs) Para Avaliação Dos Genes Abca4, Elovl4 E Prom1 E Validação Pelo Método De Sequenciamento Sanger. Os Prontuários Dos Pacientes Em Acompanhamento No Igo Que Possuíam Teste Molecular Realizado Por Ngs Foram Revisados Para Seleção Dos Casos Com Diagnóstico Clínico De Doença De Stargardt E Seus Testes Moleculares Foram Reanalisados. Resultados: Foram Incluídos 52 Pacientes De 47 Famílias. Na Primeira Fase Foram Selecionados 24 Pacientes De 21 Famílias Do Ambulatório De Retina Da UDados abertos - Sucupira - Teses e dissertações (2018

Gene panel sequencing in Brazilian patients with retinitis pigmentosa

Abstract Background Retinal dystrophies constitute a group of diseases characterized by clinical variability and pronounced genetic heterogeneity. Retinitis pigmentosa is the most common subtype of hereditary retinal dystrophy and is characterized by a progressive loss of peripheral field vision (Tunnel Vision), eventual loss of central vision, and progressive night blindness. The characteristics of the fundus changes include bone-spicule formations, attenuated blood vessels, reduced and/or abnormal electroretinograms, changes in structure imaged by optical coherence tomography, and subjective changes in visual function. The different syndromic and nonsyndromic forms of retinal dystrophies can be attributed to mutations in more than 250 genes. Molecular diagnosis for patients with retinitis pigmentosa has been hampered by extreme genetic and clinical heterogeneity between retinitis pigmentosa and other forms of retinal dystrophies. Next generation sequencing (NGS) technologies are among the most promising techniques to identify pathogenic variations in retinal dystrophies. Purpose The purpose of this study was to discover the molecular diagnosis for Brazilian patients clinically diagnosed with a retinitis pigmentosa pattern of inheritance by using NGS technologies. Materials and methods Sixteen patients with the clinical diagnosis of retinitis pigmentosa were included in the study. Their DNA was sequenced in a panel with 132 genes related to retinal dystrophies using the Illumina® platform. Sequence analysis and variation calling was performed using Soft Genetics®, NextGene, and Geneticist Assistant software. The criteria for pathogenicity analysis were established according to the results of prediction programs (Polyphen 2, Mutation taster and MetaCore™) and comparison of pathogenic variations found with databases. Results The identified potentially pathogenic variations were all confirmed by Sanger sequencing. There were 89 variations predicted as pathogenic, but only 10 of them supported the conclusion of the molecular diagnosis. Five of the nine patients were autosomal dominant RP (56%), two (22%) were autosomal recessive RP, and two (22%) were X-linked RP. Nine of the 16 patients (56%) had probably positive or positive results. Conclusion The Next Generation Sequencing used in this study allowed the molecular diagnosis to be confirmed in 56% of the patients and clarified the inheritance pattern of the patient’s retinal dystrophies

Novel Complex ABCA4 Alleles in Brazilian Patients With Stargardt Disease: Genotype-Phenotype Correlation

PURPOSE. To analyze the presence of complex alleles of the ABCA4 gene in Brazilian patients with Stargardt disease and to assess the correlation with clinical features. METHODS. This was an observational cross-sectional study. Patients with a diagnosis of Stargardt disease who presented three pathogenic variants of the ABCA4 gene or who had variants previously described as complex alleles were included. The relatives of these probands were evaluated in the segregation analysis. The patients were evaluated based on age at symptom onset and visual acuity, and the clinical characteristics were classified according to the findings observed on autofluorescence examination. RESULTS. Among the 47 families analyzed, approximately 30% (14/47) presented complex alleles. The segregation analysis in 14 families with cases of Stargardt disease identified three novel complex alleles and one previously described complex allele. The known complex allele p.[Leu541Pro; Ala1038Val] was identified in two families. The novel complex alleles identified were p.[Leu541Pro; Arg1443His] in five families, p.[Ser1642Arg; Val1682 Val1686-dell in seven families, and p. [Pro1761Arg; Arg2106Cys] in one family. Furthermore, four new variants (p.Lys22Asn, p.Asp915Asn, p. Glu1447Val, and p. Pro1761Arg) were identified in the second allele of the ABCA4 gene. CONCLUSIONS. Segregation analysis is important in order to confirm the molecular diagnosis of patients with Stargardt disease, given the frequency of complex alleles in the ABCA4 gene. The various pathogenic variation combinations observed in this study were associated with different phenotypes.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fed Univ Sao Paulo UNIFESP, Dept Ophthalmol & Visual Sci, Sao Paulo, BrazilFed Univ Sao Paulo UNIFESP, Dept Biophys, Sao Paulo, BrazilOregon Hlth & Sci Univ, Casey Eye Inst, Mol Diagnost Lab, Portland, OR 97201 USAMol Vis Lab, Hillsboro, OR USAFed Univ Sao Paulo UNIFESP, Dept Ophthalmol & Visual Sci, Sao Paulo, BrazilFed Univ Sao Paulo UNIFESP, Dept Biophys, Sao Paulo, BrazilFAPESP: 2012/50454-5Web of Scienc

PROM1 gene variations in Brazilian patients with macular dystrophy

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. Results: Of 25 medical records of patients with Stargardt disease, three records of patients with PROM1 gene sequence variations were selected for the study. The p. Asp776Val and p. Asp829Asn variants were detected in cases 1 and 2, respectively, and predicted to be pathogenicthey were probably responsible for macular dystrophy in these patients. Case 3 showed a p. Ala643Gly variant in the PROM1 gene and a single variation in the ABCA4 gene, but molecular testing results were inconclusive. Conclusions: In cases of Stargardt disease, where molecular testing results are inconclusive for pathogenic variations in the ABCA4 gene, variations in the PROM1 gene may occur and be considered responsible for the disease in the molecular analysis. This study described three cases in which variations in PROM1 gene may play a role in the pathogenesis of macular dystrophy or be associated with both autosomal recessive and autosomal dominant inheritance.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fed Univ Sao Paulo UNIFESP, Dept Ophthalmol & Visual Sci, Sao Paulo, BrazilFed Univ Sao Paulo UNIFESP, Biophys Lab, Sao Paulo, BrazilUniversidade Federal de São Paulo (UNIFESP), Dept Ophthalmol & Visual Sci, Sao Paulo, BrazilUniversidade Federal de São Paulo (UNIFESP), Biophys Lab, Sao Paulo, BrazilWeb of Scienc

Resolving the dark matter of ABCA4 for 1054 Stargardt disease probands through integrated genomics and transcriptomics

Purpose: Missing heritability in human diseases represents a major challenge, and this is particularly true for ABCA4-associated Stargardt disease (STGD1). We aimed to elucidate the genomic and transcriptomic variation in 1054 unsolved STGD and STGD-like probands. Methods: Sequencing of the complete 128-kb ABCA4 gene was performed using single-molecule molecular inversion probes (smMIPs), based on a semiautomated and cost-effective method. Structural variants (SVs) were identified using relative read coverage analyses and putative splice defects were studied using in vitro assays. Results: In 448 biallelic probands 14 known and 13 novel deep-intronic variants were found, resulting in pseudoexon (PE) insertions or exon elongations in 105 alleles. Intriguingly, intron 13 variants c.1938-621G>A and c.1938-514G>A resulted in dual PE insertions consisting of the same upstream, but different downstream PEs. The intron 44 variant c.6148-84A>T resulted in two PE insertions and flanking exon deletions. Eleven distinct large deletions were found, two of which contained small inverted segments. Uniparental isodisomy of chromosome 1 was identified in one proband. Conclusion: Deep sequencing of ABCA4 and midigene-based splice assays allowed the identification of SVs and causal deep-intronic variants in 25% of biallelic STGD1 cases, which represents a model study that can be applied to other inherited diseases.Fil: Khan, Mubeen. Radboud University Nijmegen Medical Centre; Países BajosFil: Cornelis, Stéphanie S.. Radboud University Nijmegen Medical Centre; Países BajosFil: Del Pozo Valero, Marta. Hospital Universitario Fundación Jiménez Díaz; España. Radboud University Nijmegen Medical Centre; Países BajosFil: Whelan, Laura. Trinity College; Estados UnidosFil: Runhart, Esmee H.. Radboud University Nijmegen Medical Centre; Países BajosFil: Mishra, Ketan. Radboud University Nijmegen Medical Centre; Países BajosFil: Bults, Femke. Radboud University Nijmegen Medical Centre; Países BajosFil: AlSwaiti, Yahya. St John of Jerusalem Eye Hospital Group; Palestina (ANP)Fil: AlTalbishi, Alaa. St John of Jerusalem Eye Hospital Group; Palestina (ANP)Fil: De Baere, Elfride. University of Ghent; BélgicaFil: Banfi, Sandro. Seconda Universita Degli Studi Di Napoli; ItaliaFil: Banin, Eyal. The Hebrew University of Jerusalem; IsraelFil: Bauwens, Miriam. University of Ghent; BélgicaFil: Ben Yosef, Tamar. The Ruth And Bruce Rappaport Faculty Of Medicine; IsraelFil: Boon, Camiel J. F.. Leiden University. Leiden University Medical Center; Países BajosFil: van den Born, L. Ingeborgh. Rotterdam Ophthalmic Institute; Países BajosFil: Defoort, Sabine. Universite Lille; FranciaFil: Devos, Aurore. Universite Lille; FranciaFil: Dockery, Adrian. Trinity College; Estados UnidosFil: Dudakova, Lubica. Charles University and General University Hospital; República ChecaFil: Fakin, Ana. Charles University and General University Hospital; República ChecaFil: Farrar, G. Jane. Trinity College; Estados UnidosFil: Ferraz Sallum, Juliana Maria. Universidade Federal de Sao Paulo; BrasilFil: Fujinami, Kaoru. UCL Institute of Ophthalmology; Reino UnidoFil: Gilissen, Christian. Radboud University Nijmegen Medical Centre; Países BajosFil: Glavac, Damjan. University of Ljubljana; EsloveniaFil: Gorin, Michael B.. University of California at Los Angeles. School of Medicine; Estados UnidosFil: Greenberg, Jacquie. University of Cape Town; SudáfricaFil: Hayashi, Takaaki. The Jikei University School of Medicine; JapónFil: Hettinga, Ymkje M.. Bartiméus Diagnostic Center for Complex Visual Disorders; Países BajosFil: Hoischen, Alexander. Radboud University Nijmegen Medical Centre; Países BajosFil: Hoyng, Carel B.. Radboud University Nijmegen Medical Centre; Países BajosFil: Hufendiek, Karsten. University Eye Hospital Hannover Medical School; AlemaniaFil: Jägle, Herbert. University Regensburg; AlemaniaFil: Kamakari, Smaragda. OMMA Ophthalmological Institute of Athens; GreciaFil: Karali, Marianthi. Seconda Universita Degli Studi Di Napoli; ItaliaFil: Kellner, Ulrich. No especifíca;Fil: Klaver, Caroline C. W.. Radboud University Nijmegen Medical Centre; Países BajosFil: Kousal, Bohdan. Charles University and General University Hospital; República ChecaFil: Lamey, Tina M.. University of Western Australia; AustraliaFil: MacDonald, Ian M.. University of Alberta; CanadáFil: Matynia, Anna. University of California at Los Angeles. School of Medicine; Estados UnidosFil: McLaren, Terri L.. University of Western Australia; AustraliaFil: Mena, Marcela D.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Meunier, Isabelle. Université Montpellier II; FranciaFil: Miller, Rianne. Radboud University Nijmegen Medical Centre; Países BajosFil: Newman, Hadas. Universitat Tel Aviv; IsraelFil: Ntozini, Buhle. University of Cape Town; SudáfricaFil: Oldak, Monika. No especifíca;Fil: Pieterse, Marc. Radboud University Nijmegen Medical Centre; Países BajosFil: Podhajcer, Osvaldo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Puech, Bernard. Universite Lille; FranciaFil: Ramesar, Raj. University of Cape Town; SudáfricaFil: Rüther, Klaus. No especifíca;Fil: Salameh, Manar. No especifíca;Fil: Salles, Mariana Vallim. Universidade de Sao Paulo; BrasilFil: Sharon, Dror. The Hebrew University of Jerusalem; IsraelFil: Simonelli, Francesca. Seconda Universita Degli Studi Di Napoli; ItaliaFil: Spital, Georg. No especifíca;Fil: Steehouwer, Marloes. Radboud University Nijmegen Medical Centre; Países BajosFil: Szaflik, Jacek P.. No especifíca;Fil: Thompson, Jennifer A.. No especifíca;Fil: Thuillier, Caroline. Universite Lille; FranciaFil: Tracewska, Anna M.. No especifíca;Fil: van Zweeden, Martine. Radboud University Nijmegen Medical Centre; Países BajosFil: Vincent, Andrea L.. University of Auckland; Nueva ZelandaFil: Zanlonghi, Xavier. No especifíca;Fil: Liskova, Petra. Charles University and General University Hospital; República ChecaFil: Stöhr, Heidi. Universitat Regensburg; AlemaniaFil: De Roach, John N.. University of Western Australia; AustraliaFil: Ayuso, Carmen. Hospital Universitario Fundación Jiménez Díaz; EspañaFil: Roberts, Lisa. University of Cape Town; SudáfricaFil: Weber, Bernhard H. F.. Universitat Regensburg; AlemaniaFil: Dhaenens, Claire Marie. Universite Lille; FranciaFil: Cremers, Frans P. M.. Radboud University Nijmegen Medical Centre; Países Bajo