Mutational spectrum in a Chinese cohort with congenital cataracts.

BACKGROUND: To identify the mutational spectrum in a Chinese cohort with congenital cataracts. METHODS: Probands (n = 164) with congenital cataracts and their affected or unaffected available family members were recruited for clinical examinations and panel-based next-generation sequencing, then classified into a cohort for further mutational analysis. RESULTS: After recruitment (n = 442; 228 males and 214 females), 49.32% (218/442) of subjects received a clinical diagnosis of congenital cataracts, and 56.88% (124/218) of patients received a molecular diagnosis. Eighty-four distinct variants distributed among 43 different genes, including 42 previously reported variants and 42 novel variants, were detected, and 49 gene variants were causally associated with patient phenotypes; 27.37% of variants (23/84) were commonly detected in PAX6, GJA8 and CRYGD, and the three genes covered 33.06% of cases (41/124) with molecular diagnosis. The majority of genes were classified as genes involved in nonsyndromic congenital cataracts (19/43, 44.19%) and were responsible for 56.45% of cases (70/124). The majority of functional and nucleotide changes were missense variants (53/84, 63.10%) and substitution variants (74/84, 88.10%), respectively. Nine de novo variants were identified. CONCLUSION: This study provides a reference for individualized genetic counseling and further extends the mutational spectrum of congenital cataracts.

Genetic Characteristics and Variation Spectrum of USH2A-Related Retinitis Pigmentosa and Usher Syndrome.

Purposes: We aimed to characterize the USH2A genotypic spectrum in a Chinese cohort and provide a detailed genetic profile for Chinese patients with USH2A-IRD. Methods: We designed a retrospective study wherein a total of 1,334 patients diagnosed with IRD were included as a study cohort, namely 1,278 RP and 56 USH patients, as well as other types of IEDs patients and healthy family members as a control cohort. The genotype-phenotype correlation of all participants with USH2A variant was evaluated. Results: Etiological mutations in USH2A, the most common cause of RP and USH, were found in 16.34% (n = 218) genetically solved IRD patients, with prevalences of 14.87% (190/1,278) and 50% (28/56). After bioinformatics and QC processing, 768 distinct USH2A variants were detected in all participants, including 136 disease-causing mutations present in 665 alleles, distributed in 5.81% of all participants. Of these 136 mutations, 43 were novel, nine were founder mutations, and two hot spot mutations with allele count ≥10. Furthermore, 38.5% (84/218) of genetically solved USH2A-IRD patients were caused by at least one of both c.2802T>G and c.8559-2 A>G mutations, and 36.9% and 69.6% of the alleles in the RP and USH groups were truncating, respectively. Conclusion: USH2A-related East Asian-specific founder and hot spot mutations were the major causes for Chinese RP and USH patients. Our study systematically delineated the genotype spectrum of USH2A-IRD, enabled accurate genetic diagnosis, and provided East Asian and other ethnicities with baseline data of a Chinese origin, which would better serve genetic counseling and therapeutic targets selection.

Genotypic spectrum and phenotype correlations of EYS-associated disease in a Chinese cohort.

BACKGROUND: To date, certain efforts have been made to investigate the clinical and genetic characteristics of patients with EYS mutations. However, data for Chinese patients are limited. OBJECTIVES: To perform a detailed phenotyping and genetic characterization of 55 Chinese patients with EYS-RD, and to identify risk factors for these clinical data. METHODS: A total of 55 patients with EYS-RD were recruited. Best-corrected visual acuity (BCVA), patient age, age at symptom onset, disease duration, and genetic information were collected. RESULTS: Thirty-six novel variants, three hot mutations of EYS (30.3%, c.6416G>A, c.6557G>A, c.7492G>C) and one hot region (49.06%, Laminin G domains) were identified. In all, 36.84% of the mutations occurred at base G site, and majority of mutations (56.56%) were missense. Late-truncating mutations are significantly more prevalent (41.30%). The mean age of onset was 15.65 ± 14.67 years old; it had no significant correlation with genotype. The average BCVA was 0.73 ± 0.93 LogMAR, and 61.8% of eyes had a BCVA better than 0.52 logMAR. BCVA was positively correlated with disease duration time. The mean MD was 23.18 ± 7.34 dB, MD showed a significant correlation with genotype and age. Cataract was present in 56.45% of patients, and 42.59% of patients showed an absence of pigmentation in the retina. Cataract and hyperpigmentation both showed a significant correlation with age. CONCLUSIONS: EYS-RD is associated with a moderate phenotype with onset around adolescence, but great variability. Our study largely enhances the current knowledge of phenotypic and genotypic characteristics of EYS-RD, which could pave the way for better management of these patients.

Dual-region radiomics signature: Integrating primary tumor and lymph node computed tomography features improves survival prediction in esophageal squamous cell cancer.

BACKGROUND: Preoperative prognostic biomarkers to guide individualized therapy are still in demand in esophageal squamous cell cancer (ESCC). Some studies reported that radiomic analysis based on CT images has been successfully performed to predict individual survival in EC. The aim of this study was to assess whether combining radiomics features from primary tumor and regional lymph nodes predicts overall survival (OS) better than using single-region features only, and to investigate the incremental value of the dual-region radiomics signature. METHODS: In this retrospective study, three radiomics signatures were built from preoperative enhanced CT in a training cohort (n = 200) using LASSO Cox model. Associations between each signature and survival was assessed on a validation cohort (n = 107). Prediction accuracy for the three signatures was compared. By constructing a clinical nomogram and a radiomics-clinical nomogram, incremental prognostic value of the radiomics signature over clinicopathological factors in OS prediction was assessed in terms of discrimination, calibration, reclassification and clinical usefulness. RESULTS: The dual-region radiomic signature was an independent factor, significantly associated with OS (HR: 1.869, 95% CI: 1.347, 2.592, P = 1.82e-04), which achieved better OS (C-index: 0.611) prediction either than the single-region signature (C-index:0.594-0.604). The resulted dual-region radiomics-clinical nomogram achieved the best discriminative ability in OS prediction (C-index:0.700). Compared with the clinical nomogram, the radiomics-clinical nomogram improved the calibration and classification accuracy for OS prediction with a total net reclassification improvement (NRI) of 26.9% (P=0.008) and integrated discrimination improvement (IDI) of 6.8% (P<0.001). CONCLUSION: The dual-region radiomic signature is an independent prognostic marker and outperforms single-region signature in OS for ESCC patients. Integrating the dual-region radiomics signature and clinicopathological factors improves OS prediction.

Frequency and phenotypic characteristics of RPE65 mutations in the Chinese population.

BACKGROUND: The retinoid isomerohydrolase RPE65 has received considerable attention worldwide since a successful clinical gene therapy was approved in 2017 as the first treatment for vision loss associated with RPE65-mediated inherited retinal disease. Identifying patients with RPE65 mutations is a prerequisite to assessing the patients' eligibility to receive RPE65-targeted gene therapies, and it is necessary to identify individuals who are most likely to benefit from gene therapies. This study aimed to investigate the RPE65 mutations frequency in the Chinese population and to determine the genetic and clinical characteristics of these patients. RESULTS: Only 20 patients with RPE65 mutations were identified, and RPE65 mutations were determined to be the 14th most common among all patients with genetic diagnoses. Ten novel variants and two hotspots associated with FAP were identified. A literature review revealed that a total of 57 patients of Chinese origin were identified with pathogenic mutations in the RPE65 gene. The mean best Snellen corrected visual acuity was worse (mean 1.3 ± 1.3 LogMAR) in patients older than 20 years old than in those younger than 15 years old (0.68 ± 0.92 LogMAR). Bone spicule-like pigment deposits (BSLPs) were observed in six patients; they were older than those without BSLP and those with white-yellow dots. Genotype-phenotype analysis revealed that truncating variants seem to lead to a more severe clinical presentation, while best corrected visual acuity testing and fundus changes did not correlate with specific RPE65 variants or mutation types. CONCLUSIONS: This study provides a detailed clinical-genetic assessment of patients with RPE65 mutations of Chinese origin. These results may help to elucidate RPE65 mutations in the Chinese population and may facilitate genetic counseling and the implementation of gene therapy in China.

Novel variants of ABCA4 in Han Chinese families with Stargardt disease.

BACKGROUND: Stargardt disease (STGD1) is a common recessive hereditary macular dystrophy in early adulthood or childhood, with an estimated prevalence of 1:8000 to 1:10,000. ABCA4 is the causative gene for STGD1. The current study aims at identifying the novel disease-related ABCA4 variants in Han Chinese families with STGD1 using next-generation sequencing (NGS). METHODS: In the present study, 12 unrelated Han Chinese families (19 males and 17 females) with STGD1 were tested by panel-based NGS. In order to capture the coding exons and the untranslated regions (UTRs) plus 30 bp of intronic flanking sequences of 792 genes, which were closely associated with usual ophthalmic genetic disease, we designed a customized panel, namely, Target_Eye_792_V2 chip. STGD1 patients were clinically diagnosed by experienced ophthalmologists. All the detected variants were filtered and analyzed through the public databases and in silico programs to assess potential pathogenicity. RESULTS: Twenty-one ABCA4 mutant variants were detected in 12 unrelated Han Chinese families with STGD1, containing 14 missense, three splicing, two frameshift, one small deletion, and one nonsense variants. Base on the American College of Medical Genetics (ACMG) guidelines, 8 likely pathogenic and 13 pathogenic variants were determined. The functional consequences of these mutant variants were predicted through in silico programs. Of the 21 mutant variants in ABCA4, two novel coding variants c.3017G > A and c.5167 T > C and one novel null variant c.3051-1G > A were detected in three unrelated probands. CONCLUSIONS: By panel-based NGS, 21 ABCA4 variants were confirmed in 12 unrelated Han Chinese families. Among them, 3 novel mutant variants were found, which further expanded the ABCA4 mutation spectrum in STGD1 patients.

Cell Development Deficiency and Gene Expression Dysregulation of Trisomy 21 Retina Revealed by Single-Nucleus RNA Sequencing.

Retina is a crucial tissue for capturing and processing light stimulus. It is critical to describe the characteristics of retina at the single-cell level for understanding its biological functions. A variety of abnormalities in terms of morphology and function are present in the trisomy 21 (T21) retina. To evaluate the consequences of chromosome aneuploidy on retina development, we identified the single-cell transcriptional profiles of a T21 fetus and performed comprehensive bioinformatic analyses. Our data revealed the diversity and heterogeneity of cellular compositions in T21 retina, as well as the abnormal constitution of T21 retina compared to disomic retina. In total, we identified seven major cell types and several subtypes within each cell type, followed by the detection of corresponding molecular markers, including previously reported ones and a series of novel markers. Through the analysis of the retinal differentiation process, subtypes of retinal progenitor cells (RPCs) exhibiting the potential of different retinal cell-type commitments and certain Müller glial cells (MGs) with differentiating potency were identified. Moreover, the extensive communication networks between cellular types were confirmed, among which a few ligand-receptor interactions were related to the formation and function of retina and immunoregulatory interactions. Taken together, our data provides the first ever single-cell transcriptome profiles for human T21 retina, which facilitates the understanding on the dosage effects of chromosome 21 on the development of retina.

Mutation Screening of mtDNA Combined Targeted Exon Sequencing in a Cohort With Suspected Hereditary Optic Neuropathy.

Purpose: Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA) are the two commonest forms of hereditary optic neuropathy. The aim of this study was to comprehensively investigate the incidence and spectrum of mutations in patients with suspected hereditary optic neuropathy by combining mitochondrial DNA (mtDNA) genome-wide and targeted exon sequencing. Methods: A cohort of 1101 subjects were recruited to participate in the study, comprising 177 families (177 probands and their family members, a total of 537 subjects, including 254 patients) and 164 sporadic cases with suspected hereditary optic neuropathy, and 400 unrelated control subjects for genetic analysis: all subjects (including control subjects) underwent a comprehensive ophthalmologic examination and were subjected to sequencing analysis of mtDNA genome-wide and targeted exon. Overall, targeted exon sequencing was used to screen 792 genes associated with common hereditary eye diseases, and the mtDNA genome-wide were screened by next-generation sequencing. Results: We found variants detected in 168 (40.2%, 168/418) of the 418 patients screened. Among these, 132 cases (78.6%, 132/168) were detected with known LHON disease-causing mtDNA variants; 40 cases (23.8%, 40/168) were detected with nuclear DNA (ntDNA) variants, which included 36 cases (21.4%, 36/168) with detected OPA1 mutations, 4 patients (2.4%, 4/168) with detected OPA3 mutations, and 2 patients (1.2%, 2/168) with detected TMEM126A homozygous mutation. Coexistence variation (mtDNA/mtDNA [n = 16], ntDNA/ntDNA [n = 4], mtDNA/ntDNA [n = 7]) was found in 27 patients (16.4%, 27/165), including mtDNA/ntDNA coexistence variation that was detected in seven patients. Among these ntDNA mutations, 38 distinct disease-causing variants, including autosomal recessive heterozygous mutations, were detected, which included 22 novel variants and two de novo variants. Total haplogroup distribution showed that 34.5% (29/84) and 28.6% (24/84) of the affected subjects with m.11778G>A belonged to haplogroup D and M, with a high frequency of subhaplogroups D4, D5, and M7. Conclusions: The LHON-mtDNA mutations are the commonest genetic defects in this Chinese cohort, followed by the OPA1 mutations. To our knowledge, this is the first comprehensive study of LHON, ADOA, and autosomal recessive optic atrophy combined with mtDNA genome-wide and targeted exon sequencing, as well as haplogroup analysis, in a large cohort of Chinese patients with suspected hereditary optic neuropathy. Our findings provide a powerful basis for genetic counseling in patients with suspected hereditary optic neuropathy. Translational Relevance: We applied mtDNA genome-wide sequencing combined with panel-based targeted exon sequencing to explore the pathogenic variation spectrum and genetic characteristics of patients with suspected hereditary optic neuropathy, providing a comprehensive research strategy for clinical assistant diagnosis, treatment, and genetic counseling.

Panel-based targeted exome sequencing reveals novel candidate susceptibility loci for age-related cataracts in Chinese Cohort.

BACKGROUND: Age-related cataracts (ARC) is the most common blinding eye disease worldwide, and its incidence tend to become younger. However, the relationship between genetic factors and mechanisms is not fully understood. The aim of the study was to further clarify the relationship between ARC and genetic mechanisms in East Asian populations and to elucidate the pathogenesis. METHODS: The study collected 191 sporadic cataracts and 208 healthy people from the eastern provinces of China, with an average age of about 60 years. All participants were subjected to a comprehensive ophthalmic clinical examination and peripheral blood samples were collected and their genomic DNA was extracted. Mutations were screened among 792 candidate genes to enhance understanding of the disease through targeted capture and high-throughput sequencing. RESULTS: We identified novel candidate susceptibility gene, which may serve as a potential susceptibility factor leading to an increase in the incidence of age-related cataracts. Three novel loci are associated with age-related cataracts significant significance: rs129882 in DBH (p = 5.27E-07, odds ratio = 3.9), rs1800280 in DMD (p = 2.85E-06, odds ratio = 1.4) and rs2871776 in ATP13A2 (p = 4.18E-05, odds ratio = 0.04). Gene-gene interaction analysis revealed that the most significant interactions between genes include the interaction between DBH and TUB (rs17847537 in TUB, rs129882 in DBH, p-value = 2.12E-14), and the interaction between DBH and DMD (rs1800280 in DMD, rs129882 in DBH, p-value = 2.12E-14). Pathway analysis shows that the most significant processes are concentrated in response to light stimulation (adjusted p-Value = 5.56E-03), response to radiation (adjusted P-Value = 5.56E-03), abiotic stimulus (adjusted p-Value = 5.56E-03). eQTL analysis shows that DBH rs129882 could regulate the expression of DBH mRNA in various tissues including retina. CONCLUSION: Our study indicates rs129882 and rs1800280 loci are associated with age-related cataracts, which enlarge the gene map of age-related cataracts.

Clinical and Genetic Characteristics of Chinese Patients with Occult Macular Dystrophy.

Purpose: To investigate the clinical and genetic characteristics of occult macular dystrophy (OMD) based on a Chinese patient cohort. Methods: Fifteen Chinese OMD patients from nine unrelated families underwent genetic testing, and all of them harbored a pathogenic RP1L1 variant. Comprehensive ophthalmic examinations were performed in nine probands, including spectral-domain optical coherence tomography (SD-OCT), near-infrared reflectance (NIR), fundus autofluorescence (AF), and multifocal electroretinography. Results: The RP1L1 variants p.R45W and p.S1199C were identified in 13 patients and two patients, respectively, and one was a de novo mutation. Among the nine probands, the median ages at onset and examination were 25.0 years (range, 6-51 years) and 27.0 years (range, 14-55 years), respectively. The median decimal visual acuity was 0.20 (range, 0.04-0.5). Foveal photoreceptor thickness and visual acuity showed a significant correlation (r = 0.591; P = 0.01). All eyes presented with an absent interdigitation zone and blurred ellipsoid zone of photoreceptors when examined by SD-OCT. In addition, central round lesions with low NIR reflectance were observed in 66.7% (12/18) of eyes by NIR reflectance imaging, corresponding to the regions with abnormal photoreceptor microstructures observed by SD-OCT. Of the 18 eyes, only four eyes showed ring-like faint hyperfluorescence around the macula by AF. Conclusions: To the best of our knowledge, this is the largest study in a cohort of Chinese OMD patients with RP1L1 mutations. Our findings revealed that the two recurrent RP1L1 variants are related to OMD in the Chinese population. Furthermore, multimodal imaging combined with genetic testing is valuable for diagnosing and monitoring OMD progression.

Mutation Spectrum of Stickler Syndrome Type I and Genotype-phenotype Analysis in East Asian Population: a systematic review.

BACKGROUND: Stickler syndrome is the most common genetic cause of rhegmatogenous retinal detachment (RRD) in children, and has a high risk of blindness. Type I (STL1) is the most common subtype, caused by COL2A1 mutations. This study aims to analyze the mutation spectrum of COL2A1 and further elucidate the genotype-phenotype relationships in the East Asian populations with STL1, which is poorly studied at present. METHODS: By searching MEDLINE, Web of Science, CNKI, Wanfang Data, HGMD and Clinvar, all publications associated with STL1 were collected. Then, they were carefully screened to obtain all reported STL1-related variants in COL2A1 and clinical features in East Asian patients with STL1. RESULTS: There were 274 COL2A1 variants identified in 999 patients with STL1 from 466 unrelated families, and more than half of them were truncation mutations. Of the 107 STL1 patients reported in the East Asian population, it was found that patients with truncation mutations had milder systemic phenotypes, whereas patients with splicing mutations had severer phenotypes. In addition, several recurrent variants (c.3106C > T, c.1833 + 1G > A, c.2710C > T and c.1693C > T) were found. CONCLUSIONS: Genotype-phenotype correlations should certainly be studied carefully, contributed to making personalized follow-up plans and predicting prognosis of this disorder. Genome editing holds great potential for treating inherited diseases caused by pathogenic mutations. In this study, several recurrent variants were found, providing potential candidate targets for genetic manipulation in the future.

Next-generation sequencing-aided precise diagnosis of Stickler syndrome type I.

PURPOSE: To explore an early, rapid and precise diagnosis of Stickler syndrome type I (STL1) and to enrich the spectrum of COL2A1 mutations in the Chinese population, which is poorly studied at present. METHODS: In the current study, we analysed 115 patients with high myopia by next-generation sequencing and identified five STL1 patients from four unrelated Chinese families. The clinical features of all patients were reviewed in detail. RESULTS: Four variants of COL2A1 were identified, including two novel variants (c.1435delG and c.184delG) and two previously reported variants (c.1221+1G>A and c.1030C>T). Three variants caused premature termination codons which were common in STL1. In addition, we proposed a new diagnostic tactic to improve early diagnostics of STL1 in patients. CONCLUSION: In this study, our findings expanded the spectrum of COL2A1 mutations with two novel variants and provided a new diagnostic tactic for reference, which was of great significance. Precise diagnosis on the basis of clinical manifestations and genetic testing will become the gold standard to diagnose inherited ocular disorders or syndromes in the future.

The Precise Diagnosis of Wolfram Syndrome Type 1 Based on Next-Generation Sequencing.

Purpose: To explore a method for the early, rapid and accurate diagnosis of Wolfram syndrome 1 (WS1) and further enrich the spectrum of WFS1 mutations in the Chinese population. Methods: We analyzed 279 patients with unexplained optic atrophy using next-generation sequencing. All patients underwent detailed clinical evaluations. Furthermore, Sanger sequencing and cosegregation analyses were performed within families. Results: Five patients with WS1 were identified in four unrelated families, and their clinical features were reviewed in detail. Seven variants of WFS1 were detected, including three reported variants (p.G674R, p.Tyr508Cysfs*34, and p.G702D) and four novel variants (p.W540G, p.K634*, p.F770C, and p.Q584P). Furthermore, the variant p.G674R was recurrent. Conclusion: Considering that WS1 is a rare progressive neurodegenerative disease, early diagnosis is beneficial to the systematic evaluation, monitoring and management of complications to improve patient quality of life and delay the progression of the disease. In the future, precise diagnosis on the basis of clinical manifestation and genetic testing will become the gold standard for the diagnosis of hereditary eye diseases and syndromes. Finally, our results further increase the spectrum of WFS1 mutations by adding four novel variants to the limited data available in the Chinese population.

ABCA4 Gene Screening in a Chinese Cohort With Stargardt Disease: Identification of 37 Novel Variants.

Purpose: To clarify the mutation spectrum and frequency of ABCA4 in a Chinese cohort with Stargardt disease (STGD1). Methods: A total of 153 subjects, comprising 25 families (25 probands and their family members) and 71 sporadic cases, were recruited for the analysis of ABCA4 variants. All probands with STGD1 underwent a comprehensive ophthalmologic examination. Overall, 792 genes involved in common inherited eye diseases were screened for variants by panel-based next-generation sequencing (NGS). Variants were filtered and analyzed to evaluate possible pathogenicity. Results: The total variant detection rate of at least one ABCA4 mutant allele was 84.3% (129/153): two or three disease-associated variants in 86 subjects (56.2%), one mutant allele in 43 subjects (28.1%), and no variants in 24 subjects (15.7%). Ninety-six variants were identified in the total cohort, which included 62 missense (64%), 15 splicing (16%), 11 frameshift (12%), 6 nonsense (6%), and 2 small insertion or deletion (2%) variants. Thirty-seven novel variants were found, including a de novo variant, c.4561delA. The most prevalent variant was c.101_106delCTTTAT (10.5%), followed by c.2894A > G (6.5%) and c.6563T > C (4.6%), in STGD1 patients from eastern China. Conclusion: Thirty-seven novel variants were detected using panel-based NGS, including one de novo variant, further extending the mutation spectrum of ABCA4. The common variants in a population from eastern China with STGD1 were also identified.

Genetic and Clinical Findings in a Large Cohort of Chinese Patients with Suspected Retinitis Pigmentosa.

PURPOSE: To characterize the genetic landscape of patients with suspected retinitis pigmentosa (RP) in the Chinese population. DESIGN: Cohort study. PARTICIPANTS: A total of 1243 patients of Chinese origin with clinically suspected RP and their available family members (n = 2701) were recruited. METHODS: All patients and available family members were screened using multigene panel testing (including 586 eye disease-associated genes), followed by clinical variant interpretation. MAIN OUTCOME MEASURES: Diagnostic yield, the 17 most commonly implicated genes, age at onset, de novo mutations, and clinical usefulness of genetic testing. RESULTS: Overall, 72.08% of patients received a molecular diagnosis, and the 17 top genes covered 75.63% of diagnostic cases. Diagnostic yield was higher among patients in the early-onset subgroup (≤5 years old, 79.58%) than in the childhood or adolescence-onset subgroup (6-16 years old, 73.74%) and late-onset subgroup (≥17 years old, 65.99%). Moreover, different genes associated with different onset ages and subgroups with different onset ages showed a diverse mutation spectrum. Only 11 de novo mutations (3.18%) were identified. Furthermore, 16.84% of the patients who received a molecular diagnosis had refinement of the initial clinical diagnoses, and the remaining 83.16% received definite genetic subtypes of RP. CONCLUSIONS: This large cohort study provides population-based data of the genome landscape of patients with suspected RP in China. The diagnostic yield was significantly higher than that in previous studies, and the mutation spectrum is completely different with other populations. Genetic testing improves the chance to establish a precise diagnosis, identifies features not previously determined, and allows a more accurate refinement of risk to family members. Our results not only expand the existing genotypic spectrum but also serve as an efficient reference for the design of panel-based genetic diagnostic testing and genetic counseling for patients with suspected RP in China.

Targeting circular RNA-ZRANB1 for therapeutic intervention in retinal neurodegeneration.

Glaucoma is a neurodegenerative disease characterized by retinal ganglion cell (RGC) loss, optic disc excavation, and progressive visual field loss. Direct or indirect ameliorating retinal neurodegeneration is a promising therapeutic therapy for glaucoma. Circular RNAs (circRNAs) are a class of covalently closed circular RNA transcripts and have emerged as potential regulators in several neurodegenerative diseases. In this study, we show that cZRANB1 expression is significantly upregulated in retinal neurodegeneration induced by glaucoma. cZRANB1 knockdown decreases retinal reactive gliosis, glial cell activation, and facilitates RGC survival in vivo. cZRANB1 knockdown directly regulates Müller cell function and indirectly regulates RGC function in vitro. cZRANB1 acts as miRNA sponge to regulate Müller cell function through cZRANB1/miR-217/RUNX2 network. Intervention of cZRANB1 expression would become an effective strategy for treating retinal neurodegeneration.

Targeted next-generation sequencing analysis identifies novel mutations in families with severe familial exudative vitreoretinopathy.

PURPOSE: Familial exudative vitreoretinopathy (FEVR) is a genetically and clinically heterogeneous disease, characterized by failure of vascular development of the peripheral retina. The symptoms of FEVR vary widely among patients in the same family, and even between the two eyes of a given patient. This study was designed to identify the genetic defect in a patient cohort of ten Chinese families with a definitive diagnosis of FEVR. METHODS: To identify the causative gene, next-generation sequencing (NGS)-based target capture sequencing was performed. Segregation analysis of the candidate variant was performed in additional family members by using Sanger sequencing and quantitative real-time PCR (QPCR). RESULTS: Of the cohort of ten FEVR families, six pathogenic variants were identified, including four novel and two known heterozygous mutations. Of the variants identified, four were missense variants, and two were novel heterozygous deletion mutations [LRP5, c.4053 DelC (p.Ile1351IlefsX88); TSPAN12, EX8Del]. The two novel heterozygous deletion mutations were not observed in the control subjects and could give rise to a relatively severe FEVR phenotype, which could be explained by the protein function prediction. CONCLUSIONS: We identified two novel heterozygous deletion mutations [LRP5, c.4053 DelC (p.Ile1351IlefsX88); TSPAN12, EX8Del] using targeted NGS as a causative mutation for FEVR. These genetic deletion variations exhibit a severe form of FEVR, with tractional retinal detachments compared with other known point mutations. The data further enrich the mutation spectrum of FEVR and enhance our understanding of genotype-phenotype correlations to provide useful information for disease diagnosis, prognosis, and effective genetic counseling.

Quercetin Declines Apoptosis, Ameliorates Mitochondrial Function and Improves Retinal Ganglion Cell Survival and Function in In Vivo Model of Glaucoma in Rat and Retinal Ganglion Cell Culture In Vitro.

Glaucoma is a progressive neuropathy characterized by the loss of retinal ganglion cells (RGCs). Strategies that delay or halt RGC loss have been recognized as potentially beneficial for rescuing vision in glaucoma patients. Quercetin (Qcn) is a natural and important dietary flavonoid compound, widely distributed in fruits and vegetables. Mounting evidence suggests that Qcn has numerous neuroprotective effects. However, whether Qcn exerts neuroprotective effects on RGC in glaucoma is poorly understood. In this study, we investigated the protective effect of Qcn against RGC damage in a rat chronic ocular hypertension (COHT) model invivo and hypoxia-induced primary cultured RGC damage in vitro, and we further explored the underlying neuroprotective mechanisms. We found that Qcn not only improved RGC survival and function from a very early stage of COHT invivo, it promoted the survival of hypoxia-treated primary cultured RGCs invitro via ameliorating mitochondrial function and preventing mitochondria-mediated apoptosis. Our findings suggest that Qcn has direct protective effects on RGCs that are independent of lowering the intraocular pressure (IOP). Qcn may be a promising therapeutic agent for improving RGC survival and function in glaucomatous neurodegeneration.

Circular Noncoding RNA HIPK3 Mediates Retinal Vascular Dysfunction in Diabetes Mellitus.

BACKGROUND: The vascular complications of diabetes mellitus are the major causes of morbidity and mortality among people with diabetes. Circular RNAs are a class of endogenous noncoding RNAs that regulate gene expression in eukaryotes. In this study, we investigated the role of circular RNA in retinal vascular dysfunction induced by diabetes mellitus. METHODS: Quantitative polymerase chain reactions, Sanger sequencing, and Northern blots were conducted to detect circular HIPK3 (circHIPK3) expression pattern on diabetes mellitus-related stresses. MTT (3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assays, EdU (5-ethynyl-2'-deoxyuridine) incorporation assays, Transwell migration assays, and Matrigel assays were conducted to detect the role of circHIPK3 in retinal endothelial cell function in vitro. Retinal trypsin digestion, vascular permeability assays, and ELISA assays were conducted to detect the role of circHIPK3 in retinal vascular dysfunction in vivo. Bioinformatics analysis, luciferase activity assays, RNA pull-down assays, and in vitro studies were conducted to reveal the mechanism of circHIPK3-mediated retinal vascular dysfunction. RESULTS: circHIPK3 expression was significantly upregulated in diabetic retinas and retinal endothelial cells following stressors related to diabetes mellitus. circHIPK3 silencing or overexpressing circHIPK3 changed retinal endothelial cell viability, proliferation, migration, and tube formation in vitro. circHIPK3 silencing in vivo alleviated retinal vascular dysfunction, as shown by decreased retinal acellular capillaries, vascular leakage, and inflammation. circHIPK3 acted as an endogenous miR-30a-3p sponge to sequester and inhibit miR-30a-3p activity, which led to increased vascular endothelial growth factor-C, FZD4, and WNT2 expression. Ectopic expression of miR-30a-3p mimicked the effect of circHIPK3 silencing on vascular endothelial phenotypes in vivo and in vitro. CONCLUSIONS: The circular RNA circHIPK3 plays a role in diabetic retinopathy by blocking miR-30a function, leading to increased endothelial proliferation and vascular dysfunction. These data suggest that circular RNA is a potential target to control diabetic proliferative retinopathy.

Next-Generation Sequencing-Aided Rapid Molecular Diagnosis of Occult Macular Dystrophy in a Chinese Family.

Purpose: To show early, rapid and accurate molecular diagnosis of occult macular dystrophy (OMD) in a four-generation Chinese family with inherited macular dystrophy. Methods: In the current study, we comprehensively screened 130 genes involved in common inherited non-syndromic eye diseases with next-generation sequencing-based target capture sequencing of the proband of a four-generation Chinese family that has suffered from maculopathy without a definitive diagnosis for over 10 years. Variants were filtered and analyzed to identify possible disease-causing variants before validation by Sanger sequencing. Results: Two heterozygous mutations-RP1L1 c.133 C > T (p.Arg45Trp), which is a hot spot for OMD, and ABCA4 c.6119 G > A (p.Arg2040Gln), which was identified in Stargardt's disease were found in three patients, but neither of the mutations was found in the unaffected individuals in the same family, who are phenotypically normal or in the normal control volunteers. Conclusion: These results cannot only confirm the diagnosis of OMD in the proband, but also provide presymptomatic diagnosis of the proband's children before the onset of visual acuity impairment and guidance regarding the prognosis and management of these patients. Heterozygous mutations of RP1L1 c.133 C > T (p.Arg45Trp) and ABCA4 c.6119 G > A (p.Arg2040Gln) are likely responsible for OMD. Our results further extend our current understanding of the genetic basis of OMD, and emphasize the importance of molecular diagnosis and genetic counseling for OMD.