1
|
Maggi J, Koller S, Feil S, Bachmann-Gagescu R, Gerth-Kahlert C, Berger W. Limited Added Diagnostic Value of Whole Genome Sequencing in Genetic Testing of Inherited Retinal Diseases in a Swiss Patient Cohort. Int J Mol Sci 2024; 25:6540. [PMID: 38928247 PMCID: PMC11203445 DOI: 10.3390/ijms25126540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 06/28/2024] Open
Abstract
The purpose of this study was to assess the added diagnostic value of whole genome sequencing (WGS) for patients with inherited retinal diseases (IRDs) who remained undiagnosed after whole exome sequencing (WES). WGS was performed for index patients in 66 families. The datasets were analyzed according to GATK's guidelines. Additionally, DeepVariant was complemented by GATK's workflow, and a novel structural variant pipeline was developed. Overall, a molecular diagnosis was established in 19/66 (28.8%) index patients. Pathogenic deletions and one deep-intronic variant contributed to the diagnostic yield in 4/19 and 1/19 index patients, respectively. The remaining diagnoses (14/19) were attributed to exonic variants that were missed during WES analysis due to bioinformatic limitations, newly described loci, or unclear pathogenicity. The added diagnostic value of WGS equals 5/66 (9.6%) for our cohort, which is comparable to previous studies. This figure would decrease further to 1/66 (1.5%) with a standardized and reliable copy number variant workflow during WES analysis. Given the higher costs and limited added value, the implementation of WGS as a first-tier assay for inherited eye disorders in a diagnostic laboratory remains untimely. Instead, progress in bioinformatic tools and communication between diagnostic and clinical teams have the potential to ameliorate diagnostic yields.
Collapse
Affiliation(s)
- Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (S.F.)
| | - Samuel Koller
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (S.F.)
| | - Silke Feil
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (S.F.)
| | | | - Christina Gerth-Kahlert
- Department of Ophthalmology, University Hospital Zurich and University of Zurich, 8091 Zurich, Switzerland;
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (S.F.)
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, 8057 Zurich, Switzerland
| |
Collapse
|
2
|
Jin Y, Li S, Jiang Z, Sun L, Huang L, Zhang T, Liu X, Ding X. Genotype-Phenotype of CRB1-Associated Early-Onset Retinal Dystrophy: Novel Insights on Retinal Architecture and Therapeutic Window for Clinical Trials. Invest Ophthalmol Vis Sci 2024; 65:11. [PMID: 38466290 DOI: 10.1167/iovs.65.3.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024] Open
Abstract
Purpose The purpose of this study was to investigate the genotypic and phenotypic characteristics of CRB1-associated early onset retinal dystrophy (CRB1-eoRD) and retinal architecture by swept-source optical coherence tomography (SS-OCT). Methods Eleven probands with CRB1-eoRD were recruited. Clinical information, genetic analysis, and comprehensive ophthalmic examinations including SS-OCT and SS-OCT angiography (SS-OCTA) were conducted. Results A total of 81.8% (9/11) of CRB1-eoRD presented as Leber congenital amaurosis (LCA). Common clinical manifestations included coin-like yellow-white retinal spots (20/22, 90.9%) and para-arteriolar retinal pigment epithelial retention (12/22, 54.5%). Nineteen different CRB1 variants were detected in our case series, including 12 missense, 3 frameshifts, 3 nonsense, and 1 splicing. Of them, 12 variants had been reported, and 7 were novel. SS-OCT showed thinner central macula (the LCA group, P < 0.0001), thicker total retina (P < 0.0001), thinner outer retina (P < 0.05), and thicker inner retina (P < 0.0001) compared with the healthy control. The inner/outer (I/O) retina thickness ratio of CRB1-eoRD was 3.0, higher than the healthy control of 1.2 and other inherited retinal diseases (IRDs) of 2.2 (P < 0.0001 and P = 0.0027, respectively). SS-OCTA revealed an increased vascular density and perfusion area of the superficial vascular complex and deep vascular complex in CRB1-eoRD. Conclusions LCA emerges as a frequently occurring phenotype in CRB1-eoRD. The unique features of SS-OCT and SS-OCTA are illustrated, and the novel biomarker, I/O ratio, may facilitate early diagnosis. The insights gained from this study hold significant value in determining the treatment window for potential forthcoming CRB1 gene therapy.
Collapse
Affiliation(s)
- Yili Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Songshan Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Zhaoxin Jiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Limei Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Li Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Ting Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Xinyu Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Xiaoyan Ding
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| |
Collapse
|
3
|
Fernández-Caballero L, Martín-Merida I, Blanco-Kelly F, Avila-Fernandez A, Carreño E, Fernandez-San Jose P, Irigoyen C, Jimenez-Rolando B, Lopez-Grondona F, Mahillo I, Martin-Gutierrez MP, Minguez P, Perea-Romero I, Del Pozo-Valero M, Riveiro-Alvarez R, Rodilla C, Rodriguez-Peña L, Sánchez-Barbero AI, Swafiri ST, Trujillo-Tiebas MJ, Zurita O, García-Sandoval B, Corton M, Ayuso C. PRPH2-Related Retinal Dystrophies: Mutational Spectrum in 103 Families from a Spanish Cohort. Int J Mol Sci 2024; 25:2913. [PMID: 38474159 PMCID: PMC10931554 DOI: 10.3390/ijms25052913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 02/26/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024] Open
Abstract
PRPH2, one of the most frequently inherited retinal dystrophy (IRD)-causing genes, implies a high phenotypic variability. This study aims to analyze the PRPH2 mutational spectrum in one of the largest cohorts worldwide, and to describe novel pathogenic variants and genotype-phenotype correlations. A study of 220 patients from 103 families recruited from a database of 5000 families. A molecular diagnosis was performed using classical molecular approaches and next-generation sequencing. Common haplotypes were ascertained by analyzing single-nucleotide polymorphisms. We identified 56 variants, including 11 novel variants. Most of them were missense variants (64%) and were located in the D2-loop protein domain (77%). The most frequently occurring variants were p.Gly167Ser, p.Gly208Asp and p.Pro221_Cys222del. Haplotype analysis revealed a shared region in families carrying p.Leu41Pro or p.Pro221_Cys222del. Patients with retinitis pigmentosa presented an earlier disease onset. We describe the largest cohort of IRD families associated with PRPH2 from a single center. Most variants were located in the D2-loop domain, highlighting its importance in interacting with other proteins. Our work suggests a likely founder effect for the variants p.Leu41Pro and p.Pro221_Cys222del in our Spanish cohort. Phenotypes with a primary rod alteration presented more severe affectation. Finally, the high phenotypic variability in PRPH2 hinders the possibility of drawing genotype-phenotype correlations.
Collapse
Affiliation(s)
- Lidia Fernández-Caballero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Inmaculada Martín-Merida
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Almudena Avila-Fernandez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Ester Carreño
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital, 28040 Madrid, Spain; (E.C.); (B.J.-R.); (M.P.M.-G.); (B.G.-S.)
| | - Patricia Fernandez-San Jose
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Department of Genetics, Ramón y Cajal University Hospital, 28034 Madrid, Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), 28034 Madrid, Spain
| | - Cristina Irigoyen
- Ophthalmology Service, Donostia University Hospital, 20014 Donostia-San Sebastián, Spain
| | - Belen Jimenez-Rolando
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital, 28040 Madrid, Spain; (E.C.); (B.J.-R.); (M.P.M.-G.); (B.G.-S.)
| | - Fermina Lopez-Grondona
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Ignacio Mahillo
- Department of Statistics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain;
| | - María Pilar Martin-Gutierrez
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital, 28040 Madrid, Spain; (E.C.); (B.J.-R.); (M.P.M.-G.); (B.G.-S.)
| | - Pablo Minguez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
| | - Irene Perea-Romero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Marta Del Pozo-Valero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Rosa Riveiro-Alvarez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Cristina Rodilla
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Lidya Rodriguez-Peña
- Sección de Genética Medica, Servicio de Pediatría, HCU Virgen de la Arrixaca, 30120 Murcia, Spain
| | - Ana Isabel Sánchez-Barbero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Saoud T. Swafiri
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - María José Trujillo-Tiebas
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Olga Zurita
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Blanca García-Sandoval
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital, 28040 Madrid, Spain; (E.C.); (B.J.-R.); (M.P.M.-G.); (B.G.-S.)
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (L.F.-C.); (I.M.-M.); (F.B.-K.); (A.A.-F.); (F.L.-G.); (P.M.); (C.R.); (A.I.S.-B.); (S.T.S.); (M.J.T.-T.); (O.Z.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| |
Collapse
|
4
|
Zheng Y, Chen S. Transcriptional precision in photoreceptor development and diseases - Lessons from 25 years of CRX research. Front Cell Neurosci 2024; 18:1347436. [PMID: 38414750 PMCID: PMC10896975 DOI: 10.3389/fncel.2024.1347436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/19/2024] [Indexed: 02/29/2024] Open
Abstract
The vertebrate retina is made up of six specialized neuronal cell types and one glia that are generated from a common retinal progenitor. The development of these distinct cell types is programmed by transcription factors that regulate the expression of specific genes essential for cell fate specification and differentiation. Because of the complex nature of transcriptional regulation, understanding transcription factor functions in development and disease is challenging. Research on the Cone-rod homeobox transcription factor CRX provides an excellent model to address these challenges. In this review, we reflect on 25 years of mammalian CRX research and discuss recent progress in elucidating the distinct pathogenic mechanisms of four CRX coding variant classes. We highlight how in vitro biochemical studies of CRX protein functions facilitate understanding CRX regulatory principles in animal models. We conclude with a brief discussion of the emerging systems biology approaches that could accelerate precision medicine for CRX-linked diseases and beyond.
Collapse
Affiliation(s)
- Yiqiao Zheng
- Molecular Genetics and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Saint Louis, MO, United States
- Department of Ophthalmology and Visual Sciences, Saint Louis, MO, United States
| | - Shiming Chen
- Molecular Genetics and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Saint Louis, MO, United States
- Department of Ophthalmology and Visual Sciences, Saint Louis, MO, United States
- Department of Developmental Biology, Washington University in St. Louis, Saint Louis, MO, United States
| |
Collapse
|
5
|
Kaltak M, de Bruijn P, van Leeuwen W, Platenburg G, Cremers FPM, Collin RWJ, Swildens J. QR-1011 restores defective ABCA4 splicing caused by multiple severe ABCA4 variants underlying Stargardt disease. Sci Rep 2024; 14:684. [PMID: 38182646 PMCID: PMC10770117 DOI: 10.1038/s41598-024-51203-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 01/02/2024] [Indexed: 01/07/2024] Open
Abstract
Stargardt disease type 1 (STGD1), the most common form of hereditary macular dystrophy, can be caused by biallelic combinations of over 2200 variants in the ABCA4 gene. This leads to reduced or absent ABCA4 protein activity, resulting in toxic metabolite accumulation in the retina and damage of the retinal pigment epithelium and photoreceptors. Approximately 21% of all ABCA4 variants that contribute to disease influence ABCA4 pre-mRNA splicing. This emphasizes the need for therapies to restore disrupted ABCA4 splicing and halt STGD1 progression. Previously, QR-1011, an antisense oligonucleotide (AON), successfully corrected splicing abnormalities and restored normal ABCA4 protein translation in human retinal organoids carrying the prevalent disease-causing variant c.5461-10T>C in ABCA4. Here, we investigated whether QR-1011 could also correct splicing in four less common non-canonical splice site (NCSS) variants flanking ABCA4 exon 39: c.5461-8T>G, c.5461-6T>C, c.5584+5G>A and c.5584+6T>C. We administered QR-1011 and three other AONs to midigene-transfected cells and demonstrate that QR-1011 had the most pronounced effect on splicing compared to the others. Moreover, QR-1011 significantly increased full-length ABCA4 transcript levels for c.5461-8T>G and c.5584+6T>C. Splicing restoration could not be achieved in the other two variants, suggesting their more severe effect on splicing. Overall, QR-1011, initially developed for a single ABCA4 variant, exhibited potent splice correction capabilities for two additional severe NCSS variants nearby. This suggests the possibility of a broader therapeutic impact of QR-1011 extending beyond its original target and highlights the potential for treating a larger population of STGD1 patients affected by multiple severe ABCA4 variants with a single AON.
Collapse
Affiliation(s)
- Melita Kaltak
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Petra de Bruijn
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands
| | - Willemijn van Leeuwen
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands
| | - Gerard Platenburg
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Jim Swildens
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands.
| |
Collapse
|
6
|
Chowdhary MR, Gupta N. Long-range PCR in next generation sequencing: A low cost approach for large & complex genes. Indian J Med Res 2023; 157:591-592. [PMID: 37530314 PMCID: PMC10466485 DOI: 10.4103/ijmr.ijmr_2373_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Indexed: 08/03/2023] Open
Affiliation(s)
- Madhumita Roy Chowdhary
- Division of Genetics, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi 110 029, India
| | - Neerja Gupta
- Division of Genetics, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi 110 029, India
| |
Collapse
|
7
|
Vanaja MC, Jain JMN, Dalal A, Ranganath P. Long-range PCR amplification-based targeted enrichment & next generation sequencing: A cost-effective testing strategy for lysosomal storage disorders. Indian J Med Res 2023; 157:577-590. [PMID: 37530313 PMCID: PMC10466493 DOI: 10.4103/ijmr.ijmr_2707_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Indexed: 07/08/2023] Open
Abstract
Background & objectives Lysosomal storage disorders (LSDs) are genetic metabolic disorders which result from deficiency of lysosomal enzymes or defects in other lysosomal components. Molecular genetic testing of LSDs is required for diagnostic confirmation when lysosomal enzyme assays are not available or not feasible to perform, and for the identification of the disease causing genetic variants. The aim of this study was to develop a cost-effective, readily customizable and scalable molecular genetic testing strategy for LSDs. Methods A testing method was designed based on the in-house creation of selective amplicons through long range PCR amplification for targeted capture and enrichment of different LSD genes of interest, followed by next generation sequencing of pooled samples. Results In the first phase of the study, standardization and validation of the study protocol were done using 28 samples of affected probands and/or carrier parents (group A) with previously identified variants in seven genes, and in the second phase of the study, 30 samples of enzymatically confirmed or biopsy-proven patients with LSDs and/or their carrier parents who had not undergone any prior mutation analysis (group B) were tested and the sequence variants identified in them through the study method were validated by targeted Sanger sequencing. Interpretation & conclusions This testing approach was found to be reliable, easily customizable and cost-effective for the molecular genetic evaluation of LSDs. The same strategy may be applicable, especially in resource poor settings, for developing cost-effective multigene panel tests for other conditions with genetic heterogeneity.
Collapse
Affiliation(s)
- Maria Celestina Vanaja
- Diagnostics Division, Centre for DNA Fingerprinting & Diagnostics, Hyderabad, Telangana, India
| | | | - Ashwin Dalal
- Diagnostics Division, Centre for DNA Fingerprinting & Diagnostics, Hyderabad, Telangana, India
| | - Prajnya Ranganath
- Diagnostics Division, Centre for DNA Fingerprinting & Diagnostics, Hyderabad, Telangana, India
- Department of Medical Genetics, Nizam’s Institute of Medical Sciences, Hyderabad, Telangana, India
| |
Collapse
|
8
|
Koller S, Beltraminelli T, Maggi J, Wlodarczyk A, Feil S, Baehr L, Gerth-Kahlert C, Menghini M, Berger W. Functional Analysis of a Novel, Non-Canonical RPGR Splice Variant Causing X-Linked Retinitis Pigmentosa. Genes (Basel) 2023; 14:genes14040934. [PMID: 37107692 PMCID: PMC10137330 DOI: 10.3390/genes14040934] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/05/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
X-linked retinitis pigmentosa (XLRP) caused by mutations in the RPGR gene is one of the most severe forms of RP due to its early onset and intractable progression. Most cases have been associated with genetic variants within the purine-rich exon ORF15 region of this gene. RPGR retinal gene therapy is currently being investigated in several clinical trials. Therefore, it is crucial to report and functionally characterize (all novel) potentially pathogenic DNA sequence variants. Whole-exome sequencing (WES) was performed for the index patient. The splicing effects of a non-canonical splice variant were tested on cDNA from whole blood and a minigene assay. WES revealed a rare, non-canonical splice site variant predicted to disrupt the wildtype splice acceptor and create a novel acceptor site 8 nucleotides upstream of RPGR exon 12. Reverse-transcription PCR analyses confirmed the disruption of the correct splicing pattern, leading to the insertion of eight additional nucleotides in the variant transcript. Transcript analyses with minigene assays and cDNA from peripheral blood are useful tools for the characterization of splicing defects due to variants in the RPGR and may increase the diagnostic yield in RP. The functional analysis of non-canonical splice variants is required to classify those variants as pathogenic according to the ACMG's criteria.
Collapse
Affiliation(s)
- Samuel Koller
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Tim Beltraminelli
- Department of Ophthalmology, Institute of Clinical Neurosciences of Southern Switzerland, Ente Ospedaliero Cantonale (EOC), 6962 Lugano, Switzerland
| | - Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Agnès Wlodarczyk
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Silke Feil
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Luzy Baehr
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Christina Gerth-Kahlert
- Department of Ophthalmology, University Hospital, University of Zurich, 8091 Zurich, Switzerland
| | - Moreno Menghini
- Department of Ophthalmology, Institute of Clinical Neurosciences of Southern Switzerland, Ente Ospedaliero Cantonale (EOC), 6962 Lugano, Switzerland
- Department of Ophthalmology, University Hospital, University of Zurich, 8091 Zurich, Switzerland
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, 8057 Zurich, Switzerland
| |
Collapse
|
9
|
The Diagnostic Yield of Next Generation Sequencing in Inherited Retinal Diseases: A Systematic Review and Meta-analysis. Am J Ophthalmol 2022; 249:57-73. [PMID: 36592879 DOI: 10.1016/j.ajo.2022.12.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/16/2022] [Accepted: 12/23/2022] [Indexed: 01/01/2023]
Abstract
PURPOSE Accurate genotyping of individuals with inherited retinal diseases (IRD) is essential for patient management and identifying suitable candidates for gene therapies. This study evaluated the diagnostic yield of next generation sequencing (NGS) in IRDs. DESIGN Systematic review and meta-analysis. METHODS This systematic review was prospectively registered (CRD42021293619). Ovid MEDLINE and Ovid Embase were searched on 6 June 2022. Clinical studies evaluating the diagnostic yield of NGS in individuals with IRDs were eligible for inclusion. Risk of bias assessment was performed. Studies were pooled using a random...effects inverse variance model. Sources of heterogeneity were explored using stratified analysis, meta-regression, and sensitivity analysis. RESULTS This study included 105 publications from 28 countries. Most studies (90 studies) used targeted gene panels. The diagnostic yield of NGS was 61.3% (95% confidence interval: 57.8-64.7%; 51 studies) in mixed IRD phenotypes, 58.2% (51.6-64.6%; 41 studies) in rod-cone dystrophies, 57.7% (46.8-68.3%; eight studies) in macular and cone/cone-rod dystrophies, and 47.6% (95% CI: 41.0-54.3%; four studies) in familial exudative vitreoretinopathy. For mixed IRD phenotypes, a higher diagnostic yield was achieved pooling studies published between 2018-2022 (64.2% [59.5-68.7%]), studies using exome sequencing (73.5% [58.9-86.1%]), and studies using the American College of Medical Genetics variant interpretation standards (65.6% [60.8-70.4%]). CONCLUSION The current diagnostic yield of NGS in IRDs is between 52-74%. The certainty of the evidence was judged as low or very low. A key limitation of the current evidence is the significant heterogeneity between studies. Adoption of standardized reporting guidelines could improve confidence in future meta-analyses.
Collapse
|
10
|
Peters F, Ebner LJA, Atac D, Maggi J, Berger W, den Hollander AI, Grimm C. Regulation of ABCA1 by AMD-Associated Genetic Variants and Hypoxia in iPSC-RPE. Int J Mol Sci 2022; 23:ijms23063194. [PMID: 35328615 PMCID: PMC8953808 DOI: 10.3390/ijms23063194] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 02/04/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive disease of the macula characterized by atrophy of the retinal pigment epithelium (RPE) and photoreceptor degeneration, leading to severe vision loss at advanced stages in the elderly population. Impaired reverse cholesterol transport (RCT) as well as intracellular lipid accumulation in the RPE are implicated in AMD pathogenesis. Here, we focus on ATP-binding cassette transporter A1 (ABCA1), a major cholesterol transport protein in the RPE, and analyze conditions that lead to ABCA1 dysregulation in induced pluripotent stem cell (iPSC)-derived RPE cells (iRPEs). Our results indicate that the risk-conferring alleles rs1883025 (C) and rs2740488 (A) in ABCA1 are associated with increased ABCA1 mRNA and protein levels and reduced efficiency of cholesterol efflux from the RPE. Hypoxia, an environmental risk factor for AMD, reduced expression of ABCA1 and increased intracellular lipid accumulation. Treatment with a liver X receptor (LXR) agonist led to an increase in ABCA1 expression and reduced lipid accumulation. Our data strengthen the homeostatic role of cholesterol efflux in the RPE and suggest that increasing cellular cholesterol export by stimulating ABCA1 expression might lessen lipid load, improving RPE survival and reducing the risk of developing AMD.
Collapse
Affiliation(s)
- Florian Peters
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
- Correspondence: (F.P.); (C.G.)
| | - Lynn J. A. Ebner
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
| | - David Atac
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Anneke I. den Hollander
- Department of Ophthalmology, Radboud University Medical Center, 6525 Nijmegen, The Netherlands;
- AbbVie, Genomic Research Center, 200 Sidney Street, Cambridge, MA 02139, USA
| | - Christian Grimm
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
- Correspondence: (F.P.); (C.G.)
| |
Collapse
|