scholarly journals Phenocopy of a heterozygous carrier of X-linked retinitis pigmentosa due to mosaicism for a RHO variant

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ine Strubbe ◽  
Caroline Van Cauwenbergh ◽  
Julie De Zaeytijd ◽  
Sarah De Jaegere ◽  
Marieke De Bruyne ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Somatic Mosaicism ◽  
Retinal Disease ◽  
Hair Follicles ◽  
Disease Genes ◽  
Female Carrier ◽  
Autofluorescence Imaging ◽  
Targeted Next Generation Sequencing ◽  
Whole Exome ◽  
Next Generation Sequencing Ngs

AbstractWe describe both phenotype and pathogenesis in two male siblings with typical retinitis pigmentosa (RP) and the potentially X-linked RP (XLRP) carrier phenotype in their mother. Two affected sons, two unaffected daughters, and their mother underwent detailed ophthalmological assessments including Goldmann perimetry, color vision testing, multimodal imaging and ISCEV-standard electroretinography. Genetic testing consisted of targeted next-generation sequencing (NGS) of known XLRP genes and whole exome sequencing (WES) of known inherited retinal disease genes (RetNet-WES). Variant validation and segregation analysis were performed by Sanger sequencing. The mutational load of the RHO variant in the mother was assessed in DNA from leucocytes, buccal cells and hair follicles using targeted NGS. Both affected sons showed signs of classical RP, while the mother displayed patches of hyperautofluorescence on blue light autofluorescence imaging and regional, intraretinal, spicular pigmentation, reminiscent of a carrier phenotype of XLRP. XLRP testing was negative. RetNet-WES testing revealed RHO variant c.404G > C p.(Arg135Pro) in a mosaic state (21% of the reads) in the mother and in a heterozygous state in both sons. Targeted NGQSS of the RHO variant in different maternal tissues showed a mutation load between 25.06% and 41.72%. We report for the first time that somatic mosaicism of RHO variant c.404G > C p.(Arg135Pro) mimics the phenotype of a female carrier of XLRP, in combination with heterozygosity for the variant in the two affected sons.

scholarly journals Clinical Phenotype of PDE6B-Associated Retinitis Pigmentosa

2021 ◽  
Vol 22 (5) ◽  
pp. 2374
Author(s):  
Laura Kuehlewein ◽  
Ditta Zobor ◽  
Katarina Stingl ◽  
Melanie Kempf ◽  
Fadi Nasser ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Genetic Testing ◽  
Retinitis Pigmentosa ◽  
Fundus Autofluorescence ◽  
Retinal Disease ◽  
New Drugs ◽  
Autofluorescence Imaging ◽  
Full Field ◽  
Tertiary Referral Center ◽  
The Right

In this retrospective, longitudinal, observational cohort study, we investigated the phenotypic and genotypic features of retinitis pigmentosa associated with variants in the PDE6B gene. Patients underwent clinical examination and genetic testing at a single tertiary referral center, including best-corrected visual acuity (BCVA), kinetic visual field (VF), full-field electroretinography, full-field stimulus threshold, spectral domain optical coherence tomography, and fundus autofluorescence imaging. The genetic testing comprised candidate gene sequencing, inherited retinal disease gene panel sequencing, whole-genome sequencing, and testing for familial variants by Sanger sequencing. Twenty-four patients with mutations in PDE6B from 21 families were included in the study (mean age at the first visit: 32.1 ± 13.5 years). The majority of variants were putative splicing defects (8/23) and missense (7/23) mutations. Seventy-nine percent (38/48) of eyes had no visual acuity impairment at the first visit. Visual acuity impairment was mild in 4% (2/48), moderate in 13% (6/48), and severe in 4% (2/48). BCVA was symmetrical in the right and left eyes. The kinetic VF measurements were highly symmetrical in the right and left eyes, as was the horizontal ellipsoid zone (EZ) width. Regarding the genetic findings, 43% of the PDE6B variants found in our patients were novel. Thus, this study contributed substantially to the PDE6B mutation spectrum. The visual acuity impairment was mild in 83% of eyes, providing a window of opportunity for investigational new drugs. The EZ width was reduced in all patients and was highly symmetric between the eyes, making it a promising outcome measure. We expect these findings to have implications on the design of future PDE6B-related retinitis pigmentosa (RP) clinical trials.

scholarly journals Diverse Genetic Landscape of Suspected Retinitis Pigmentosa in a Large Korean Cohort

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 675
Author(s):  
Yoon-Jeon Kim ◽  
You-Na Kim ◽  
Young-Hee Yoon ◽  
Eul-Ju Seo ◽  
Go-Hun Seo ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Detection Rate ◽  
Mutation Detection ◽  
Retinal Disease ◽  
Mutation Detection Rate ◽  
Targeted Next Generation Sequencing ◽  
Initial Symptoms ◽  
Genetic Landscape ◽  
History Of ◽  
Genetic Profiles

We conducted targeted next-generation sequencing (TGS) and/or whole exome sequencing (WES) to assess the genetic profiles of clinically suspected retinitis pigmentosa (RP) in the Korean population. A cohort of 279 unrelated Korean patients with clinically diagnosed RP and available family members underwent molecular analyses using TGS consisting of 88 RP-causing genes and/or WES with clinical variant interpretation. The combined genetic tests (TGS and/or WES) found a mutation in the 44 RP-causing genes and seven inherited retinal disease (IRD)-causing genes, and the total mutation detection rate was 57%. The mutation detection rate was higher in patients who experienced visual deterioration at a younger age (75.4%, age of symptom onset under 10 years) and who had a family history of RP (70.7%). The most common causative genes were EYS (8.2%), USH2A (6.8%), and PDE6B (4.7%), but mutations were dispersed among the 51 RP/IRD genes generally. Meanwhile, the PDE6B mutation was the most common in patients experiencing initial symptoms in their first decade, EYS in their second to third decades, and USH2A in their fifth decades and older. Of note, WES revealed some unexpected genotypes: ABCC6, CHM, CYP4V2, RS1, TGFBI, VPS13B, and WDR19, which were verified by ophthalmological re-phenotyping.

scholarly journals Clinical characteristics and disease progression of retinitis pigmentosa associated with PDE6B mutations in Korean patients

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
You Na Kim ◽  
Joon Seon Song ◽  
Seak Hee Oh ◽  
Yoon Jeon Kim ◽  
Young Hee Yoon ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Disease Progression ◽  
Sequencing Data ◽  
Korean Patients ◽  
Targeted Next Generation Sequencing ◽  
Whole Exome ◽  
Structural Progression ◽  
Novel Variant ◽  
Whole Exome Sequencing Data ◽  
Phenotype Heterogeneity

Abstract Due to the genotype–phenotype heterogeneity in retinitis pigmentosa (RP), molecular diagnoses and prediction of disease progression is difficult. This study aimed to report ocular and genetic data from Korean patients with PDE6B-associated RP (PDE6B-RP), and establish genotype–phenotype correlations to predict the clinical course. We retrospectively reviewed targeted next-generation sequencing or whole exome sequencing data for 305 patients with RP, and identified PDE6B-RP in 15 patients (median age, 40.0 years). Amongst these patients, ten previously reported PDE6B variants (c.1280G > A, c.1488del, c.1547T > C, c.1604T > A, c.1669C > T, c.1712C > T, c.2395C > T, c.2492C > T, c.592G > A, and c.815G > A) and one novel variant (c.712del) were identified. Thirteen patients (86.7%) experienced night blindness as the first symptom at a median age of 10.0 years. Median age at diagnosis was 21.0 years and median visual acuity (VA) was 0.20 LogMAR at the time of genetic analysis. Nonlinear mixed models were developed and analysis revealed that VA exponentially decreased over time, while optical coherence tomography parameters linearly decreased, and this was related with visual field constriction. A high proportion of patients with the c.1669C > T variant (7/9, 77.8%) had cystoid macular edema; despite this, patients with this variant did not show a higher rate of functional or structural progression. This study will help clinicians predict functional and structural progression in patients with PDE6B-RP.

scholarly journals AAV-Txnip prolongs cone survival and vision in mouse models of retinitis pigmentosa

2021 ◽  
Author(s):  
Yunlu Xue ◽  
Sean K. Wang ◽  
Parimal Rana ◽  
Emma R. West ◽  
Christin M. Hong ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Mouse Models ◽  
Retinal Disease ◽  
Disease Genes ◽  
Cone Photoreceptors ◽  
Adeno Associated Virus ◽  
Rescue Effect ◽  
Inherited Retinal Disease ◽  
High Acuity

AbstractRetinitis pigmentosa (RP) is an inherited retinal disease, affecting >20 million people worldwide. Loss of daylight vision typically occurs due to the dysfunction/loss of cone photoreceptors, the cell type that initiates our color and high acuity vision. Currently, there is no effective treatment for RP, other than gene therapy for a limited number of specific disease genes. To develop a gene-agnostic therapy, we screened ≈20 genes for their ability to prolong cone photoreceptor survival in vivo. Here, we report an adeno-associated virus (AAV) vector expressing Txnip, which prolongs the survival of cone photoreceptors and improves visual acuity in RP mouse models. A Txnip allele, C247S, which blocks the association of Txnip with thioredoxin, provides an even greater benefit. Additionally, the rescue effect of Txnip depends on lactate dehydrogenase b (Ldhb), and correlates with the presence of healthier mitochondria, suggesting that Txnip saves RP cones by enhancing their lactate catabolism.

scholarly journals Detection and validation of six pathogenic variants in Chinese inherited heart disease patients using clinical whole-exome sequencing

2021 ◽  
Author(s):  
Lichao Cao ◽  
Fei Ye ◽  
Shuqi Xie ◽  
Ying Ba ◽  
Ying Zeng ◽  
...  
Keyword(s):  
Heart Disease ◽  
Next Generation Sequencing ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Sanger Sequencing ◽  
Targeted Next Generation Sequencing ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

The targeted next-generation sequencing (NGS) was employed in detecting the pathogenic mutations in inherited heart disease patients in the present study. Two main methods, the NGS and the classic Sanger sequencing, were used in this study. And, the whole-exome sequencing (WES) was specifically used in this study.

scholarly journals Further phenotypic delineation of the auriculocondylar syndrome type 2 with literature review

2020 ◽  
Author(s):  
Ewelina Bukowska-Olech ◽  
Anna Sowińska-Seidler ◽  
Filip Łojek ◽  
Delfina Popiel ◽  
Joanna Walczak-Sztulpa ◽  
...  
Keyword(s):  
Somatic Mosaicism ◽  
Missense Variant ◽  
Pharyngeal Arches ◽  
Developmental Defects ◽  
Targeted Next Generation Sequencing ◽  
Phenotypic Spectrum ◽  
Whole Exome ◽  
Low Coverage ◽  
Generation Sequencing

AbstractAuriculocondylar syndrome (ACS) is an ultra-rare disorder that arises from developmental defects of the first and second pharyngeal arches. Three subtypes of ACS have been described so far, i.e., ACS1 (MIM: 602483), ACS2 (MIM: 600810), and ACS3 (MIM: 131240). The majority of patients, however, are affected by ACS2, which results from the mutations in the PLCB4 gene. Herein, we have described an 8-year-old male patient presenting with ACS2 and summarized the molecular and phenotypic spectrum of the syndrome. We have also compared the clinical features of our case to three other previously described cases (one sporadic and two familial) harboring the same heterozygous missense variant c.1862G>A, p.Arg621His in the PLCB4 gene. The mutation was detected using whole-exome sequencing (WES). Due to low coverage of WES and suspicion of somatic mosaicism, the variant was additionally reassessed by deep targeted next-generation sequencing panel of genes related to the craniofacial disorders, and next confirmed by Sanger sequencing. ACS2 presents high intra- and interfamilial phenotypic heterogeneity that impedes reaching an exact clinical and molecular diagnosis. Thus, describing additional cases, carrying even the known mutation, but resulting in variable phenotypes, is essential for better understanding of such orphan Mendelian diseases.

scholarly journals Autosomal Recessive Retinitis Pigmentosa Associated with Three Novel REEP6 Variants in Chinese Population

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 537
Author(s):  
Lujia Zhang ◽  
Ya Li ◽  
Litao Qin ◽  
Yu Wu ◽  
Bo Lei
Keyword(s):  
Retinitis Pigmentosa ◽  
Autosomal Recessive ◽  
Cultured Cells ◽  
Missense Variant ◽  
Chinese Families ◽  
Targeted Next Generation Sequencing ◽  
Novel Variants ◽  
Next Generation Sequencing Ngs ◽  
Computational Predictions

Retinitis pigmentosa 77 is caused by mutations of REEP6 (MIM: 609346), which encodes a protein for the development of photoreceptors. Our study was to identify disease-causing variants in three Chinese families using targeted next-generation sequencing (NGS). Multiple lines of computational predictions combined with in vitro cellular experiments were applied to evaluate the pathogenicity of the newly found variants. Three novel variants in REEP6, including one missense variant, c.268G>C, one frameshift variant, c.468delC, and one splicing variant, c.598+1G>C, were found, while c.268G>C was detected in all probands. The three variants were classified as likely pathogenic by the American College of Medical Genetics and Genomics (ACMG). REEP6 variant proteins c.268G>C and c.468delC in cultured cells destabilized the REEP6 protein and induced intracellular inclusions. Our data suggested that REEP6 c.268G>C may be a recurrent causative variant in Chinese autosomal recessive retinitis pigmentosa patients.

scholarly journals Panel-based NGS Reveals Novel Pathogenic Mutations in Autosomal Recessive Retinitis Pigmentosa

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Raquel Perez-Carro ◽  
Marta Corton ◽  
Iker Sánchez-Navarro ◽  
Olga Zurita ◽  
Noelia Sanchez-Bolivar ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Autosomal Recessive ◽  
Copy Number Variations ◽  
Single Nucleotide ◽  
Targeted Next Generation Sequencing ◽  
Large Deletions ◽  
Retinal Dystrophies ◽  
Pathogenic Mutations ◽  
Detection Of Mutations ◽  
Next Generation Sequencing Ngs

Abstract Retinitis pigmentosa (RP) is a group of inherited progressive retinal dystrophies (RD) characterized by photoreceptor degeneration. RP is highly heterogeneous both clinically and genetically, which complicates the identification of causative genes and mutations. Targeted next-generation sequencing (NGS) has been demonstrated to be an effective strategy for the detection of mutations in RP. In our study, an in-house gene panel comprising 75 known RP genes was used to analyze a cohort of 47 unrelated Spanish families pre-classified as autosomal recessive or isolated RP. Disease-causing mutations were found in 27 out of 47 cases achieving a mutation detection rate of 57.4%. In total, 33 pathogenic mutations were identified, 20 of which were novel mutations (60.6%). Furthermore, not only single nucleotide variations but also copy-number variations, including three large deletions in the USH2A and EYS genes, were identified. Finally seven out of 27 families, displaying mutations in the ABCA4, RP1, RP2 and USH2A genes, could be genetically or clinically reclassified. These results demonstrate the potential of our panel-based NGS strategy in RP diagnosis.

scholarly journals AAV-Txnip prolongs cone survival and vision in mouse models of retinitis pigmentosa

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Yunlu Xue ◽  
Sean K Wang ◽  
Parimal Rana ◽  
Emma R West ◽  
Christin M Hong ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Mouse Models ◽  
Retinal Disease ◽  
Disease Genes ◽  
Cone Photoreceptors ◽  
Adeno Associated Virus ◽  
Rescue Effect ◽  
Inherited Retinal Disease ◽  
High Acuity

Retinitis pigmentosa (RP) is an inherited retinal disease, affecting >20 million people worldwide. Loss of daylight vision typically occurs due to the dysfunction/loss of cone photoreceptors, the cell type that initiates our color and high acuity vision. Currently, there is no effective treatment for RP, other than gene therapy for a limited number of specific disease genes. To develop a disease gene-agnostic therapy, we screened 20 genes for their ability to prolong cone photoreceptor survival in vivo. Here, we report an adeno-associated virus (AAV) vector expressing Txnip, which prolongs the survival of cone photoreceptors and improves visual acuity in RP mouse models. A Txnip allele, C247S, which blocks the association of Txnip with thioredoxin, provides an even greater benefit. Additionally, the rescue effect of Txnip depends on lactate dehydrogenase b (Ldhb), and correlates with the presence of healthier mitochondria, suggesting that Txnip saves RP cones by enhancing their lactate catabolism.

scholarly journals Genetic Profile and Associated Characteristics of 150 Korean Patients with Retinitis Pigmentosa

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
You Na Kim ◽  
Yoon Jeon Kim ◽  
Chang Ahn Seol ◽  
Eul-Ju Seo ◽  
Joo Yong Lee ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Genetic Profile ◽  
Epiretinal Membranes ◽  
Korean Patients ◽  
Targeted Next Generation Sequencing ◽  
Nonlinear Mixed Models ◽  
Targeted Ngs ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

Purpose. Retinitis pigmentosa (RP) shows great diversity between genotypes and phenotypes, and it is important to identify the causative genes. This study aimed to analyze the molecular profiles, associated ocular characteristics, and progression of RP in Korean patients. Methods. All the genetic variants in patients with RP, identified using targeted next-generation sequencing (NGS) with a panel of 88 RP-related genes between November 2018 and November 2019, were retrospectively reviewed. All the patients underwent comprehensive ophthalmological evaluations, and their clinical and family histories were recorded. The best-corrected visual acuity (BCVA) deterioration and photoreceptor disruption progression rates were determined based on the major causative mutational genes using nonlinear mixed models, and the differences among them were investigated using the interaction effect. Results. Among the 144 probands, 82 variants in 24 causative genes were identified in 77 families (53.5%). Most of the RP cases were associated with autosomal recessive variants (N = 64 (44.4%)), followed by autosomal dominant (N = 10 (6.9%)) and X-linked variants (N = 3 (2.1%)). The four most frequently affected genes were EYS (N = 15 (10.4%)), USH2A (N = 12 (8.3%)), PDE6B (N = 9 (6.3%)), and RP1 (N = 8 (5.6%)). Epiretinal membranes and cystoid macular edema were frequently noted in the patients with USH2A (75.0%) and PDE6B (50.0%) variants, respectively. During the follow-up period, the BCVA and photoreceptor disruption changes were significantly different among the patients carrying the four common causative genes ( P = 0.014 and 0.034, resp.). Patients with PDE6B variants showed faster BCVA changes (0.2 LogMAR/10 years), and those with USH2A variants showed the fastest ellipsoid zone disruptions (−170.4 µm/year). Conclusion. In conclusion, our genetic analysis using targeted NGS provides information about the prevalence of RP-associated mutations in Korean patients. Delineating clinical characteristics according to genetic variations may help clinicians identify subtype features and predict the clinical course of RP.

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