RESUMEN
BACKGROUND: Leber congenital amaurosis 1 (LCA1), caused by mutations in GUCY2D, is a rare inherited retinal disease that typically causes blindness in early childhood. The aim of this study was to evaluate the safety and preliminary efficacy of ascending doses of ATSN-101, a subretinal AAV5 gene therapy for LCA1. METHODS: 15 patients with genetically confirmed biallelic mutations in GUCY2D were included in this phase 1/2 study. All patients received unilateral subretinal injections of ATSN-101. In the dose-escalation phase, three adult cohorts (n=3 each) were treated with three ascending doses: 1·0â×â1010 vg/eye (low dose), 3·0â×â1010 vg/eye (middle dose), and 1·0â×â1011 vg/eye (high dose). In the dose-expansion phase, one adult cohort (n=3) and one paediatric cohort (n=3) were treated at the high dose. The primary endpoint was the incidence of treatment-emergent adverse events (TEAEs), and secondary endpoints included full-field stimulus test (FST) and best-corrected visual acuity (BCVA). A multi-luminance mobility test (MLMT) was also done. Data through the 12-month main study period are reported. FINDINGS: Patients were enrolled between Sept 12, 2019, and May 5, 2022. A total of 68 TEAEs were observed, 56 of which were related to the surgical procedure. No serious TEAE was related to the study drug. Ocular inflammation was mild and reversible with steroid treatment. For patients who received the high dose, mean change in dark-adapted FST was 20·3 decibels (dB; 95% CI 6·6 to 34·0) for treated eyes and 1·1 dB (-3·7 to 5·9) for untreated eyes at month 12 (white stimulus); improvements were first observed at day 28 and persisted over 12 months (p=0·012). Modest improvements in BCVA were also observed (p=0·10). Three of six patients who received the high dose and did the MLMT achieved the maximum score in the treated eye. INTERPRETATION: ATSN-101 is well tolerated 12 months after treatment, with no drug-related serious adverse events. Clinically significant improvements in retinal sensitivity were sustained in patients receiving the high dose. FUNDING: Atsena Therapeutics.
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Terapia Genética , Guanilato Ciclasa , Amaurosis Congénita de Leber , Receptores de Superficie Celular , Adolescente , Adulto , Niño , Humanos , Terapia Genética/métodos , Guanilato Ciclasa/genética , Inyecciones Intraoculares , Amaurosis Congénita de Leber/genética , Mutación , Receptores de Superficie Celular/genética , Resultado del Tratamiento , Agudeza VisualRESUMEN
Inherited retinopathies are devastating diseases that in most cases lack treatment options. Disease-modifying therapies that mitigate pathophysiology regardless of the underlying genetic lesion are desirable due to the diversity of mutations found in such diseases. We tested a systems pharmacology-based strategy that suppresses intracellular cAMP and Ca2+ activity via G protein-coupled receptor (GPCR) modulation using tamsulosin, metoprolol, and bromocriptine coadministration. The treatment improves cone photoreceptor function and slows degeneration in Pde6ßrd10 and RhoP23H/WT retinitis pigmentosa mice. Cone degeneration is modestly mitigated after a 7-month-long drug infusion in PDE6A-/- dogs. The treatment also improves rod pathway function in an Rpe65-/- mouse model of Leber congenital amaurosis but does not protect from cone degeneration. RNA-sequencing analyses indicate improved metabolic function in drug-treated Rpe65-/- and rd10 mice. Our data show that catecholaminergic GPCR drug combinations that modify second messenger levels via multiple receptor actions provide a potential disease-modifying therapy against retinal degeneration.
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Modelos Animales de Enfermedad , Reposicionamiento de Medicamentos , Retinitis Pigmentosa , Animales , Ratones , Perros , Retinitis Pigmentosa/tratamiento farmacológico , Retinitis Pigmentosa/genética , Mutación , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 6/genética , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 6/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Ratones Noqueados , Amaurosis Congénita de Leber/tratamiento farmacológico , Amaurosis Congénita de Leber/genética , Bromocriptina/farmacología , Bromocriptina/uso terapéutico , cis-trans-Isomerasas/genética , cis-trans-Isomerasas/metabolismo , Humanos , Quimioterapia Combinada , Ratones Endogámicos C57BL , Células Fotorreceptoras Retinianas Conos/efectos de los fármacos , Células Fotorreceptoras Retinianas Conos/metabolismo , Células Fotorreceptoras Retinianas Conos/patología , Femenino , AMP Cíclico/metabolismo , Degeneración Retiniana/tratamiento farmacológico , Degeneración Retiniana/genética , Masculino , Calcio/metabolismoRESUMEN
PURPOSE: This study aimed to characterize the clinical features, genetic findings, and genotype-phenotype correlations of patients with Leber congenital amaurosis (LCA) or early-onset severe retinal dystrophy (EOSRD) harboring biallelic AIPL1 pathogenic variants. DESIGN: Retrospective case series. METHODS: This study consecutively enrolled 51 patients from 47 families with a clinical diagnosis of LCA/EOSRD harboring disease-causing variants in the AIPL1 gene, from October 2021 to September 2023. Molecular genetic findings, medical history, and ophthalmic evaluation including visual acuity (VA), multimodal retinal imaging, and electrophysiologic assessment were reviewed. RESULTS: Of the 51 patients (32 with LCA and 19 with EOSRD), 27 (53%) were females, and age at last review ranged from 0.5 to 58.4 years. We identified 28 disease-causing AIPL1 variants, with 18 being novel. In patients with EOSRD, the mean (range) VA was 1.3 (0.7-2.7) logMAR and 1.3 (0.5-2.3) logMAR for right and left eyes respectively, with an average annual decline of 0.03 logMAR (R2 = 0.7547, P < .01). For patients with LCA, the VA ranged from light perception to counting fingers. Optical coherence tomography imaging demonstrated preservation of foveal ellipsoid zone in the 5 youngest EOSRD patients and 9 LCA children. Electroretinography showed severe cone-rod patterns in 78.6% (11/14) of patients with EOSRD, while classical extinguished pattern was documented in all patients with LCA available for the examination. The most common mutation was the nonsense variants of c.421C>T, with an allele frequency of 53.9%. All patients with EOSRD carried at least one missense mutation, of whom 13 identified with c.152A>G and 5 with c.572T>C. Twenty-six patients with LCA harbored two null AIPL1 variants, while 18 were homozygous for c.421C>T and 6 were heterozygous for c.421C>T with another loss-of-function variant. CONCLUSIONS: This study reveals distinct clinical features and variation spectrum between AIPL1-associated LCA and EOSRD. Patients harboring at least one nonnull mutation, especially c.152A>G and c.572T>C, were significantly more likely to have a milder EOSRD phenotype than those with two null mutations. Residual foveal outer retinal structure observed in the youngest proportion of patients suggests an early window for gene augmentation therapy.
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Electrorretinografía , Amaurosis Congénita de Leber , Mutación , Distrofias Retinianas , Tomografía de Coherencia Óptica , Agudeza Visual , Humanos , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/fisiopatología , Amaurosis Congénita de Leber/diagnóstico , Femenino , Masculino , Estudios Retrospectivos , Niño , Distrofias Retinianas/genética , Distrofias Retinianas/fisiopatología , Distrofias Retinianas/diagnóstico , Preescolar , Agudeza Visual/fisiología , Adulto , Adolescente , Persona de Mediana Edad , Lactante , Adulto Joven , Proteínas Adaptadoras Transductoras de Señales/genética , Análisis Mutacional de ADN , Estudios de Asociación Genética , Linaje , Imagen Multimodal , Enfermedades Hereditarias del OjoRESUMEN
Leber congenital amaurosis (LCA)/early-onset severe retinal dystrophy (EOSRD) stand as primary causes of incurable childhood blindness. This study investigates the clinical and molecular architecture of syndromic and non-syndromic LCA/EOSRD within a Chilean cohort (67 patients/60 families). Leveraging panel sequencing, 95.5% detection was achieved, revealing 17 genes and 126 variants (32 unique). CRB1, LCA5, and RDH12 dominated (71.9%), with CRB1 being the most prevalent (43.8%). Notably, four unique variants (LCA5 p.Glu415*, CRB1 p.Ser1049Aspfs*40 and p.Cys948Tyr, RDH12 p.Leu99Ile) constituted 62.7% of all disease alleles, indicating their importance for targeted analysis in Chilean patients. This study underscores a high degree of inbreeding in Chilean families affected by pediatric retinal blindness, resulting in a limited mutation repertoire. Furthermore, it complements and reinforces earlier reports, indicating the involvement of ADAM9 and RP1 as uncommon causes of LCA/EOSRD. These data hold significant value for patient and family counseling, pharmaceutical industry endeavors in personalized medicine, and future enrolment in gene therapy-based treatments, particularly with ongoing trials (LCA5) or advancing preclinical developments (CRB1 and RDH12).
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Mutación , Distrofias Retinianas , Humanos , Distrofias Retinianas/genética , Distrofias Retinianas/terapia , Distrofias Retinianas/diagnóstico , Chile/epidemiología , Masculino , Femenino , Niño , Preescolar , Oxidorreductasas de Alcohol/genética , Proteínas de la Membrana/genética , Proteínas del Ojo/genética , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/terapia , Amaurosis Congénita de Leber/diagnóstico , Linaje , Proteínas del Tejido Nervioso/genética , Adolescente , Alelos , Variación Genética , Enfermedades Hereditarias del OjoRESUMEN
TRiC/CCT is a chaperonin complex required for the folding of cytoplasmic proteins. Although mutations in each subunit of TRiC/CCT are associated with various human neurodegenerative diseases, their impact in mammalian models has not yet been examined. A compound heterozygous mutation in CCT2 (p.[Thr400Pro]; p.[Arg516His]) is causal for Leber congenital amaurosis. Here, we generate mice carrying each mutation and show that Arg516His (R516H) homozygosity causes photoreceptor degeneration accompanied by a significant depletion of TRiC/CCT substrate proteins in the retina. In contrast, Thr400Pro (T400P) homozygosity results in embryonic lethality, and the compound heterozygous mutant (T400P/R516H) mouse showed aberrant cone cell lamination and died 2 weeks after birth. Finally, CCDC181 is identified as a interacting protein for CCTß protein, and its localization to photoreceptor connecting cilia is compromised in the mutant mouse. Our results demonstrate the distinct impact of each mutation in vivo and suggest a requirement for CCTß in ciliary maintenance.
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Chaperonina con TCP-1 , Modelos Animales de Enfermedad , Amaurosis Congénita de Leber , Animales , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/metabolismo , Amaurosis Congénita de Leber/patología , Ratones , Chaperonina con TCP-1/genética , Chaperonina con TCP-1/metabolismo , Mutación , Heterocigoto , Ratones Endogámicos C57BLRESUMEN
The clinical success of CRISPR therapies hinges on the safety and efficacy of Cas proteins. The Cas9 from Francisella novicida (FnCas9) is highly precise, with a negligible affinity for mismatched substrates, but its low cellular targeting efficiency limits therapeutic use. Here, we rationally engineer the protein to develop enhanced FnCas9 (enFnCas9) variants and broaden their accessibility across human genomic sites by ~3.5-fold. The enFnCas9 proteins with single mismatch specificity expanded the target range of FnCas9-based CRISPR diagnostics to detect the pathogenic DNA signatures. They outperform Streptococcus pyogenes Cas9 (SpCas9) and its engineered derivatives in on-target editing efficiency, knock-in rates, and off-target specificity. enFnCas9 can be combined with extended gRNAs for robust base editing at sites which are inaccessible to PAM-constrained canonical base editors. Finally, we demonstrate an RPE65 mutation correction in a Leber congenital amaurosis 2 (LCA2) patient-specific iPSC line using enFnCas9 adenine base editor, highlighting its therapeutic utility.
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Proteína 9 Asociada a CRISPR , Sistemas CRISPR-Cas , Francisella , Edición Génica , Humanos , Edición Génica/métodos , Proteína 9 Asociada a CRISPR/metabolismo , Proteína 9 Asociada a CRISPR/genética , Sistemas CRISPR-Cas/genética , Francisella/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Amaurosis Congénita de Leber/genética , Streptococcus pyogenes/genética , Células HEK293 , Mutación , ARN Guía de Sistemas CRISPR-Cas/genética , ARN Guía de Sistemas CRISPR-Cas/metabolismo , Ingeniería de Proteínas/métodos , Genoma HumanoRESUMEN
PURPOSE: To investigate autism spectrum disorder (ASD) indicators in children with Leber congenital amaurosis (LCA). STUDY DESIGN: Cross-sectional, prospective, and correlational study. METHODS: Setting: It was conducted at the Institute of Ocular Genetics, the Department of Ophthalmology at Federal University of São Paulo (UNIFESP), and the Autism Spectrum Disorder Laboratory, in São Paulo, Brazil. PATIENT POPULATION: Participants included patients aged 2 to 16 years with LCA confirmed by genetic testing. There were 20 individuals with ciliopathies (LCA cilio) and 26 with other gene mutations (LCA other). As intervention, the instrument used for ASD screening was the Autism Behavior Checklist (ABC). Marginal descriptive analyses, non-parametric tests, and a linear regression model were conducted. The main outcomes were the scores on the tests correlated with clinical variables. RESULTS: Of the 46 participants, 6 had ASD scores. There was no statistically significant correlation between the different groups (LCA cilio and LCA other) (p = 0.438). There was no statistically significant correlation between age and ASD (p = 0.308). However, there was a statistically significant correlation between visual acuity and ASD (p = 0.008) and between male gender and ASD (p = 0.025). CONCLUSIONS: This study suggests that there is no correlation between LCA cilio, LCA other and ASD. These findings bring new insights to the existing literature, which previously lacked robust data on the relationship between LCA and ASD. These data demonstrate that visual acuity plays a crucial role in the development of children with visual impairment as poorer visual acuity is associated with a higher incidence of ASD. Based on this study, early interventions can be designed, especially for individuals without light perception, with the aim of maximizing their developmental outcomes. Furthermore, such data indicates that any improvement in visual acuity outcomes in treatment clinical trials become relevant for child development. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.
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Trastorno del Espectro Autista , Amaurosis Congénita de Leber , Humanos , Niño , Masculino , Trastorno del Espectro Autista/diagnóstico , Trastorno del Espectro Autista/fisiopatología , Femenino , Adolescente , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/diagnóstico , Amaurosis Congénita de Leber/fisiopatología , Preescolar , Estudios Prospectivos , Estudios Transversales , Agudeza Visual/fisiología , Mutación , Proteínas del Ojo/genéticaRESUMEN
PURPOSE: To present the clinical characteristics, retinal features, natural history, and genetics of RPGRIP1-associated early-onset severe retinal dystrophy (EOSRD)/Leber congenital amaurosis (LCA). DESIGN: Retrospective case series. METHODS: Review of clinical notes, multimodal retinal imaging, and molecular diagnosis of 18 patients (17 families) with EOSRD/LCA and disease-causing variants in RPGRIP1. RESULTS: The mean age of visual symptoms onset was 0.87 ± 1 year (birth to 3 years), and the mean age at baseline visit was 11.4 ± 10.2 years (1-39 years). At the baseline visit, 44% of patients were legally blind (range, 2-39 years), and there was no significant association found between age and best-corrected visual acuity (BCVA) in cross-sectional analysis. Retinal evaluation showed an abolished electroretinogram or a cone-rod dystrophy pattern, no or minimal pigment deposits, a hyperautofluorescent ring at the posterior pole, and a largely preserved central macular architecture, with retained outer nuclear layer and ellipsoid zone island into adulthood. Eleven variants (48%) were previously unreported, and 13 families (76%) had a double-null (DN) genotype. Twelve patients (67%) had follow-up assessments over a 15.7 ± 9.5-year period. The rate of BCVA decline was 0.02 logarithm of the minimum angle of resolution (1 letter)/year. CONCLUSIONS: RPGRIP1 EOSRD/LCA often presents at birth or early infancy, with nystagmus, decreased visual acuity, hyperopia, and photophobia. Patients with a DN genotype may develop symptoms earlier and have worse vision. Multimodal imaging may show a hyperautofluorescent posterior pole ring and relatively preserved central macular architecture, suggesting that the condition is a promising candidate for gene supplementation.
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Electrorretinografía , Amaurosis Congénita de Leber , Proteínas , Distrofias Retinianas , Tomografía de Coherencia Óptica , Agudeza Visual , Humanos , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/diagnóstico , Amaurosis Congénita de Leber/fisiopatología , Estudios Retrospectivos , Masculino , Femenino , Adolescente , Adulto , Niño , Preescolar , Agudeza Visual/fisiología , Distrofias Retinianas/genética , Distrofias Retinianas/diagnóstico , Distrofias Retinianas/fisiopatología , Adulto Joven , Lactante , Proteínas/genética , Proteínas del Citoesqueleto/genética , Estudios Transversales , Mutación , Angiografía con Fluoresceína/métodos , Análisis Mutacional de ADN , Enfermedades Hereditarias del OjoRESUMEN
The canonical visual cycle employing RPE65 as the retinoid isomerase regenerates 11-cis-retinal to support both rod- and cone-mediated vision. Mutations of RPE65 are associated with Leber congenital amaurosis that results in rod and cone photoreceptor degeneration and vision loss of affected patients at an early age. Dark-reared Rpe65-/- mouse has been known to form isorhodopsin that employs 9-cis-retinal as the photosensitive chromophore. The mechanism regulating 9-cis-retinal synthesis and the role of the endogenous 9-cis-retinal in cone survival and function remain largely unknown. In this study, we found that ablation of fatty acid transport protein-4 (FATP4), a negative regulator of 11-cis-retinol synthesis catalyzed by RPE65, increased the formation of 9-cis-retinal, but not 11-cis-retinal, in a light-independent mechanism in both sexes of RPE65-null rd12 mice. Both rd12 and rd12;Fatp4-/- mice contained a massive amount of all-trans-retinyl esters in the eyes, exhibiting comparable scotopic vision and rod degeneration. However, expression levels of M- and S-opsins as well as numbers of M- and S-cones surviving in the superior retinas of rd12;Fatp4-/ - mice were at least twofold greater than those in age-matched rd12 mice. Moreover, FATP4 deficiency significantly shortened photopic b-wave implicit time, improved M-cone visual function, and substantially deaccelerated the progression of cone degeneration in rd12 mice, whereas FATP4 deficiency in mice with wild-type Rpe65 alleles neither induced 9-cis-retinal formation nor influenced cone survival and function. These results identify FATP4 as a new regulator of synthesis of 9-cis-retinal, which is a "cone-tropic" chromophore supporting cone survival and function in the retinas with defective RPE65.
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Proteínas de Transporte de Ácidos Grasos , Amaurosis Congénita de Leber , Células Fotorreceptoras Retinianas Conos , Animales , Células Fotorreceptoras Retinianas Conos/metabolismo , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/metabolismo , Amaurosis Congénita de Leber/patología , Ratones , Proteínas de Transporte de Ácidos Grasos/metabolismo , Proteínas de Transporte de Ácidos Grasos/genética , Masculino , Femenino , cis-trans-Isomerasas/genética , cis-trans-Isomerasas/metabolismo , cis-trans-Isomerasas/deficiencia , Supervivencia Celular , Ratones Noqueados , Diterpenos , Visión Ocular/fisiología , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , RetinaldehídoRESUMEN
Biallelic mutations in the RPE65 gene affect nearly 8% of Leber Congenital Amaurosis and 2% of Retinitis Pigmentosa cases. Voretigene neparvovec (VN) is the first gene therapy approach approved for their treatment. To date, real life experience has demonstrated functional improvements following VN treatment, which are consistent with the clinical trials outcomes. However, there is currently no consensus on the characteristics for eligibility for VN treatment. We reviewed relevant literature to explore whether recommendations on patient eligibility can be extrapolated following VN marketing. We screened 166 papers through six research questions, following scoping reviews methodology, to investigate: (1) the clinical and genetic features considered in VN treatment eligibility; (2) the psychophysical tests and imaging modalities used in the pre-treatment and follow-up; (3) the potential correlations between visual function and retinal structure that can be used to define treatment impact on disease progression; (4) retinal degeneration; (5) the most advanced testing modalities; and (6) the impact of surgical procedure on treatment outcomes. Current gaps concerning patients' eligibility in clinical settings, such as pre-treatment characteristics and outcomes are not consistently reported across the studies. No upper limit of retinal degeneration can be defined as the univocal factor in patient eligibility, although evidence suggested that the potential for function rescue is related to the preservation of photoreceptors before treatment. In general, paediatric patients retain more viable cells, present a less severe disease stage and show the highest potential for improvements, making them the most suitable candidates for treatment.
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Terapia Genética , Mutación , Distrofias Retinianas , cis-trans-Isomerasas , Humanos , cis-trans-Isomerasas/genética , Terapia Genética/métodos , Distrofias Retinianas/genética , Distrofias Retinianas/terapia , Ensayos Clínicos como Asunto , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/terapia , Amaurosis Congénita de Leber/fisiopatología , Dependovirus/genética , Agudeza Visual/fisiología , Vectores GenéticosRESUMEN
PURPOSE: Leber congenital amaurosis (LCA) is a group of early-onset retinal degenerative disorders, resulting in blindness in children. This study aimed to describe the clinical and genetic characteristics of a cohort of patients with LCA and to investigate the retinal vascular characteristics in LCA patients. METHODS: Fifty-two children with LCA were included in the study. All patients underwent detailed ocular examinations. Electroretinography (ERG) was used to evaluate the retinal function. Optical coherence tomography (OCT) was used to assess the structure change of the retina for those patients who were able to cooperate very well. Panel-based next-generation sequencing was performed to identify pathogenic variants in genes associated with LCA. Diameters of the retinal vessels were measured using the EVision AI screening system with an artificial intelligence (AI) technique. An ultrasound Doppler was used to evaluate hemodynamic parameters, including peak systolic velocity (PSV), resistive index (RI), and pulsatility index (PI), in the ophthalmic, central retinal, posterior ciliary, carotid, and internal carotid as well as external carotid arteries in 12 patients aged from 3 to 14 years. RESULTS: We detected 75 pathogenic variants from ten genes of RPGRIP1, CEP290, GUCY2D, LCA5, AIPL1, CRB1, RPE65, CRX, RDH12, and TULP1, including 29 novel and 36 previously reported variants in 52 affected children with LCA, with the highest detective rate in RPGRIP1 (26.9%). Fundus appearance is diverse in patients with LCA, ranging from normal to severe peripheral or central retinopathy. Retinal vasculature was evaluated in 12 patients with different gene variants, showing narrowed arteries with an average diameter of 43.6 ± 3.8 µm compared to that of 51.7 ± 2.6 µm in the normal controls (P < 0.001, n = 12). Meanwhile, their hemodynamic parameters were changed as well in the ophthalmic artery (OA), with a decreased PSV (P = 0.0132, n = 12) and slightly increased PI (P = 0.0488, n = 12) compared to the normal controls. However, the hemodynamic parameters did not change significantly in the other vessels. CONCLUSIONS: Blood supply to the eyeball is predicted to be reduced in patients with LCA, presumably due to photoreceptor cell degeneration. The novel identified variants will expand the spectrum of variants in LCA-related genes and be useful for studying the molecular mechanisms of LCA.
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Electrorretinografía , Amaurosis Congénita de Leber , Mutación , Tomografía de Coherencia Óptica , Humanos , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/fisiopatología , Amaurosis Congénita de Leber/diagnóstico , Masculino , Niño , Femenino , Tomografía de Coherencia Óptica/métodos , Adolescente , Preescolar , Vasos Retinianos , Proteínas del Ojo/genética , Agudeza Visual , ADN/genética , Análisis Mutacional de ADN , Retina/fisiopatologíaRESUMEN
Leber Congenital Amaurosis 2 is an early onset retinal dystrophy that occurs due to mutation in RPE65 gene. Here, we report the generation of two patient specific induced pluripotent stem cell lines harboring nonsense mutations in exon 7 (c.646A > T) and exon 9 (c.992G > A) of RPE65 gene, respectively, which leads to premature translational termination and formation of defective protein. These lines were generated by the reprogramming of human dermal fibroblast cells using integration-free, episomal constructs expressing stemness genes. The stable lines maintained a normal karyotype, expressed the key stemness factors, underwent trilineage differentiation, and maintained their genetic identity and genomic integrity.
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Células Madre Pluripotentes Inducidas , Amaurosis Congénita de Leber , cis-trans-Isomerasas , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/patología , cis-trans-Isomerasas/genética , cis-trans-Isomerasas/metabolismo , Mutación , Línea Celular , Diferenciación Celular , Masculino , Fibroblastos/metabolismo , FemeninoRESUMEN
Crumbs homolog 1 (CRB1) is one of the key genes linked to retinitis pigmentosa and Leber congenital amaurosis, which are characterized by a high clinical heterogeneity. The Crumbs family member CRB2 has a similar protein structure to CRB1, and in zebrafish, Crb2 has been shown to interact through the extracellular domain. Here, we show that CRB1 and CRB2 co-localize in the human retina and human iPSC-derived retinal organoids. In retina-specific pull-downs, CRB1 was enriched in CRB2 samples, supporting a CRB1-CRB2 interaction. Furthermore, novel interactors of the crumbs complex were identified, representing a retina-derived protein interaction network. Using co-immunoprecipitation, we further demonstrate that human canonical CRB1 interacts with CRB1 and CRB2, but not with CRB3, which lacks an extracellular domain. Next, we explored how missense mutations in the extracellular domain affect CRB1-CRB2 interactions. We observed no or a mild loss of CRB1-CRB2 interaction, when interrogating various CRB1 or CRB2 missense mutants in vitro. Taken together, our results show a stable interaction of human canonical CRB2 and CRB1 in the retina.
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Amaurosis Congénita de Leber , Retinitis Pigmentosa , Animales , Humanos , Pez Cebra/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Retina/metabolismo , Retinitis Pigmentosa/genética , Retinitis Pigmentosa/metabolismo , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/metabolismo , Proteínas del Ojo/genética , Proteínas del Ojo/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Proteínas Portadoras/metabolismoRESUMEN
Genetic diseases affecting the retina can result in partial or complete loss of visual function. Leber's congenital amaurosis (LCA) is a rare blinding disease, usually inherited in an autosomally recessive manner, with no cure. Retinal gene therapy has been shown to improve vision in LCA patients caused by mutations in the RPE65 gene (LCA2). However, little is known about how activity in central visual pathways is affected by the disease or by subsequent gene therapy. Functional MRI (fMRI) was used to assess retinal signal transmission in cortical and subcortical visual structures before and 1 year after retinal intervention. The fMRI paradigm consisted of 15-s blocks of flickering (8 Hz) black and white checkerboards interleaved with 15 s of blank (black) screen. Visual activation in the brain was assessed using the general linear model, with multiple comparisons corrected using the false discovery rate method. Response to visual stimulation through untreated eyes of LCA2 patients showed heightened fMRI responses in the superior colliculus and diminished activities in the lateral geniculate nucleus (LGN) compared to controls, indicating a shift in the patients' visual processing towards the retinotectal pathway. Following gene therapy, stimuli presented to the treated eye elicited significantly stronger fMRI responses in the LGN and primary visual cortex, indicating some re-engagement of the geniculostriate pathway (GS) pathway. Across patients, the post-treatment LGN fMRI responses correlated significantly with performance on a clinical test measuring light sensitivity. Our results demonstrate that the low vision observed in LCA2 patients involves a shift in visual processing toward the retinotectal pathway, and that gene therapy partially reinstates visual transmission through the GS pathway. This selective boosting of retinal output through the GS pathway and its correlation to improved visual performance, following several years of degenerative retinal disease, is striking. However, while retinal gene therapy and other ocular interventions have given hope to RPE65 patients, it may take years before development of therapies tailored to treat the diseases in other low vision patients are available. Our demonstration of a shift toward the retinotectal pathway in these patients may spur the development of new tools and rehabilitation strategies to help maximize the use of residual visual abilities and augment experience-dependent plasticity.
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Terapia Genética , Amaurosis Congénita de Leber , Imagen por Resonancia Magnética , Vías Visuales , Humanos , Terapia Genética/métodos , Vías Visuales/fisiopatología , Vías Visuales/diagnóstico por imagen , Adulto , Masculino , Femenino , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/terapia , Amaurosis Congénita de Leber/fisiopatología , Adulto Joven , Estimulación Luminosa/métodos , Persona de Mediana Edad , cis-trans-Isomerasas/genéticaRESUMEN
Leber congenital amaurosis (LCA) and early-onset retinal degeneration (EORD) are inherited retinal diseases (IRD) characterized by early-onset vision impairment. Herein, we studied 15 Saudi families by whole exome sequencing (WES) and run-of-homozygosity (ROH) detection via AutoMap in 12/15 consanguineous families. This revealed (likely) pathogenic variants in 11/15 families (73%). A potential founder variant was found in RPGRIP1. Homozygous pathogenic variants were identified in known IRD genes (ATF6, CRB1, CABP4, RDH12, RIMS2, RPGRIP1, SPATA7). We established genotype-driven clinical reclassifications for ATF6, CABP4, and RIMS2. Specifically, we observed isolated IRD in the individual with the novel RIMS2 variant, and we found a retina-enriched RIMS2 isoform conserved but not annotated in mouse. The latter illustrates potential different phenotypic consequences of pathogenic variants depending on the particular tissue/cell-type specific isoforms they affect. Lastly, a compound heterozygous genotype in GUCY2D in one non-consanguineous family was demonstrated, and homozygous variants in novel candidate genes ATG2B and RUFY3 were found in the two remaining consanguineous families. Reporting these genes will allow to validate them in other IRD cohorts. Finally, the missing heritability of the two unsolved IRD cases may be attributed to variants in non-coding regions or structural variants that remained undetected, warranting future WGS studies.
Asunto(s)
Consanguinidad , Secuenciación del Exoma , Linaje , Fenotipo , Humanos , Femenino , Masculino , Retina/patología , Homocigoto , Enfermedades de la Retina/genética , Isoformas de Proteínas/genética , Exoma/genética , Mutación , Niño , Predisposición Genética a la Enfermedad , Amaurosis Congénita de Leber/genética , Estudios de Cohortes , Genotipo , Estudios de Asociación Genética/métodosRESUMEN
BACKGROUND: As gene-specific therapy for inherited retinal dystrophy (IRD) advances, unified variant interpretation across institutes is becoming increasingly important. This study aims to update the genetic findings of 86 retinitis pigmentosa (RP)-related genes in a large number of Japanese patients with RP by applying the standardised variant interpretation guidelines for Japanese patients with IRD (J-IRD-VI guidelines) built upon the American College of Medical Genetics and Genomics and the Association for Molecular Pathology rules, and assess the contribution of these genes in RP-allied diseases. METHODS: We assessed 2325 probands with RP (n=2155, including n=1204 sequenced previously with the same sequencing panel) and allied diseases (n=170, newly analysed), including Usher syndrome, Leber congenital amaurosis and cone-rod dystrophy (CRD). Target sequencing using a panel of 86 genes was performed. The variants were interpreted according to the J-IRD-VI guidelines. RESULTS: A total of 3564 variants were detected, of which 524 variants were interpreted as pathogenic or likely pathogenic. Among these 524 variants, 280 (53.4%) had been either undetected or interpreted as variants of unknown significance or benign variants in our earlier study of 1204 patients with RP. This led to a genetic diagnostic rate in 38.6% of patients with RP, with EYS accounting for 46.7% of the genetically solved patients, showing a 9% increase in diagnostic rate from our earlier study. The genetic diagnostic rate for patients with CRD was 28.2%, with RP-related genes significantly contributing over other allied diseases. CONCLUSION: A large-scale genetic analysis using the J-IRD-VI guidelines highlighted the population-specific genetic findings for Japanese patients with IRD; these findings serve as a foundation for the clinical application of gene-specific therapies.
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Retinitis Pigmentosa , Femenino , Humanos , Masculino , Distrofias de Conos y Bastones/genética , Distrofias de Conos y Bastones/patología , Pueblos del Este de Asia/genética , Predisposición Genética a la Enfermedad , Variación Genética , Japón , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/patología , Mutación , Retinitis Pigmentosa/genética , Retinitis Pigmentosa/patología , Síndromes de Usher/genéticaRESUMEN
PURPOSE: To evaluate ocular and retinal features of CRB1-associated early onset severe retinal dystrophy/Leber congenital amaurosis (EOSRD/LCA) for age-related changes. DESIGN: Retrospective cohort study. METHODS: Sixteen pediatric patients with biallelic CRB1 EOSRD/LCA who had been followed for up to 18 years were reviewed. Results of comprehensive ophthalmic examinations-including visual acuity, refractive error, dark-adapted visual threshold, Goldmann perimetry, and macular optical coherence tomography (OCT)-were analyzed for significant age-related changes using mixed-effects models. RESULTS: Visual acuity dark-adapted visual sensitivity, and area of seeing visual field (all subnormal from the earliest ages recorded) declined with increasing age. Hyperopia was stable through childhood and adolescence. In CRB1 EOSRD/LCA, OCT extrafoveal inner and outer laminar thicknesses exceeded those in controls but varied little with age, and foveal metrics (depth, breadth, thickness at rim) differed significantly from those in controls, but variations in foveal metrics were not associated with declines in acuity. CONCLUSIONS: From the youngest ages, retinal and visual function is significantly subnormal and becomes progressively compromized. A goal of future therapies should be intervention at young ages, when there is more function to be rescued.
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Proteínas del Ojo , Amaurosis Congénita de Leber , Proteínas de la Membrana , Proteínas del Tejido Nervioso , Tomografía de Coherencia Óptica , Agudeza Visual , Campos Visuales , Humanos , Niño , Estudios Retrospectivos , Agudeza Visual/fisiología , Masculino , Adolescente , Femenino , Preescolar , Proteínas del Ojo/genética , Proteínas del Tejido Nervioso/genética , Proteínas de la Membrana/genética , Campos Visuales/fisiología , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/fisiopatología , Pruebas del Campo Visual , Distrofias Retinianas/genética , Distrofias Retinianas/fisiopatología , Distrofias Retinianas/diagnóstico , Adaptación a la Oscuridad/fisiología , Lactante , Envejecimiento/fisiología , Estudios de Seguimiento , Retina/fisiopatología , Adulto JovenRESUMEN
Leber congenital amaurosis (LCA) is a congenital, early onset, autosomal recessive inherited retinal disease (IRD). This report describes an LCA12 patient-specific iPSC line (LVPEIi006-A), generated by the reprogramming of dermal fibroblasts using integration-free episomal plasmids.This disease-specific iPSC model carries a homozygous point mutation in RD3, within the donor splice site at the end of exon 2 (c.296 + 1G > A). The stable line at passage 15 has displayed a normal colony morphology, expressed multiple stemness and pluripotency markers, lost all transgenes, differentiated into cell types of all three germ layers, and maintained a normal karyotype.
Asunto(s)
Homocigoto , Células Madre Pluripotentes Inducidas , Amaurosis Congénita de Leber , Células Madre Pluripotentes Inducidas/metabolismo , Amaurosis Congénita de Leber/genética , Amaurosis Congénita de Leber/patología , Humanos , Línea Celular , Mutación , Diferenciación CelularRESUMEN
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.
Asunto(s)
Amaurosis Congénita de Leber , Distrofias Retinianas , Humanos , Retina/diagnóstico por imagen , Distrofias Retinianas/diagnóstico , Distrofias Retinianas/genética , Amaurosis Congénita de Leber/diagnóstico , Amaurosis Congénita de Leber/genética , Genotipo , Fenotipo , Proteínas del Ojo/genética , Proteínas de la Membrana/genética , Proteínas del Tejido Nervioso/genéticaRESUMEN
INTRODUCTION: Mutations in the retinal pigment epithelial 65 kilodalton protein (RPE65) gene are associated with various inherited retinal diseases (IRDs), including Leber congenital amaurosis (LCA), early-onset severe retinal dystrophy (EOSRD), and retinitis pigmentosa (RP). We screened for mutations in RPE65 in a series of Indian patients with these IRDs to determine the frequency/types of mutations and to describe the associated phenotypes. MATERIALS AND METHODS: Diagnosis of LCA, EOSRD, and RP was made by standard and pre-defined criteria. Patients were evaluated by clinical, retinal imaging, and electrophysiological parameters. Genomic DNA from patients and available family members were used for identifying mutations by direct Sanger sequencing of the RPE65 gene or targeted NGS gene panel for IRDs covering 260+ genes. Variations detected were tested in healthy control populations and for co-segregation with the disease in available family members. RESULTS: Mutations were found in eight patients, out of 220 total cases screened, all homozygous for the respective mutant alleles. Seven patients had mutations leading to premature termination codons and one patient had a missense change. The onset of visual loss ranged from birth to <2 years of life. At presentation, RPE mottling in the background retina was present in all cases with macular involvement in five cases with or without vascular attenuation and optic disc pallor. CONCLUSION: RPE65 mutations in this series were found in 3.6% of cases associated with severe, early-onset disease, with consistent RPE mottling and variable manifestations with regard to the extent of disc pallor, arteriolar attenuation, and appearance of the macula.