Search

To establish disease progression rates in total lesion size (TLS), decreased autofluorescence (DAF) area, total macular volume (TMV), and mean macular sensitivity (MMS) in PRPH2-associated retinal dystrophy.Single-center, retrospective chart review.Patients with heterozygous pathogenic or likely pathogenic PRPH2 variants.Patients who underwent serial ultrawide-field (UWF) fundus autofluorescence (FAF), OCT, and Macular Integrity Assessment microperimetry with at least 1 year of follow-up were included. Linear correlation was performed in eyes of all patients to determine the rate of change over time.Outcome measures included changes in TLS, DAF area, TMV, and MMS.Twelve patients (mean age, 55) from 10 unrelated families attended 100 clinic visits, which spanned over a mean (SD) of 4.7 (2.0) years. Mean (SD) TLS and DAF radius expansion were 0.14 (0.12) and 0.10 (0.08) mm/year, respectively. Mean (SD) TMV change was -0.071 (0.040) mmSerial measurements of UWF-FAF-derived TLS and DAF showed slow expansion. Total macular volume might be a more sensitive measure than MMS in detecting disease progression.

To investigate concordance in symptom onset, area of dark autofluorescence (DAF), and growth rate (GR) between Stargardt disease siblings at an age-matched time point.In this retrospective longitudinal study of sibling pairs with identical biallelic ABCA4 variants, age at symptom onset, best-corrected visual acuity, atrophy area, and effective radius of DAF on ultra-widefield fundus autofluorescence were recorded. Absolute intersibling differences for both eyes were compared with absolute interocular differences using the Mann-Whitney test.Overall 39 patients from 19 families were recruited. In 16 families, age-matched best-corrected visual acuity and DAF were compared between siblings. In 8 families, DAF GR was compared. The median (range) absolute difference in age at symptom onset between siblings was 3 (0-35) years. Absolute intersibling differences in age-matched best-corrected visual acuity were greater than interocular differences ( P = 0.01). Similarly, absolute intersibling differences in DAF area and radius were greater than interocular differences ( P = 0.04 for area and P = 0.001 for radius). Differences between absolute interocular and intersibling GR were not statistically significant ( P = 0.44 for area GR and P = 0.61 for radius GR).There was significant discordance in age-matched best-corrected visual acuity and DAF beyond the expected limits of interocular asymmetry. Lack of significant intersibling differences in GR warrants further investigation.

Background: Mutations in the RCC1 and BTB domain-containing protein 1 (RCBTB1) gene have been implicated in a rare form of retinal dystrophy. Herein, we report the clinical features of a 45-year-ol...

The c.1430A > G (Asp477Gly) variant in RPE65 has been reported in Irish and Scottish families with either an autosomal dominant retinal dystrophy (adRD) that resembles choroideremia, a vitelliform macular dystrophy or an isolated macular atrophy. We report novel features on multimodal imaging and the natural history of a family harbouring this variant in combination with the BEST1 c.37C > T (Arg13Cys) variant. Members of a family with an adRD were examined clinically to ascertain phenotype and underwent genetic testing. Multimodal imaging included widefield colour fundus photography, quantitative autofluorescence (qAF) and spectral domain optical coherence tomography. Electrophysiology and microperimetry were also performed. Vision loss was attributed to foveal atrophy in the proband and choroidal neovascularisation and a vitello-eruptive lesion in one affected son. Peripheral retinal white dots corresponding to subretinal deposits were seen in three patients. The median qAF8 values in the proband (I:1) were low (40 and 101 in OD and OS) at age 79. Similarly, the qAF8 values for the middle son (II:2) were also low (100 and 87 in ODS and OS) at age 60. Electrophysiology showed disproportionate reduction in Arden ratio prior to the gradual loss of full-field responses. Microperimetry demonstrated an enlarging scotoma in the proband. The coexistence of the pathogenic BEST1 c.37C > T variant may modify clinical features observed in RPE65 adRD. This study expands our understanding of RPE65 adRD as a retinoid cycle disorder supported by the reduced qAF, fine white retinal dots and corresponding subretinal deposits on OCT in affected members.

Heterozygous c.440 G > T mutation in the S-antigen visual arrestin (SAG) gene has been described as a cause of autosomal dominant retinitis pigmentosa (adRP) in a series of patients of Hispanic ori...

Mutations in the splicing factor pre-messenger RNA processing factor 31 (PRPF31) gene cause autosomal dominant retinitis pigmentosa 11 (RP11) through a haplo-insufficiency mechanism. We describe th...

The ATP-binding cassette subfamily A member 4 gene (ABCA4)-associated retinopathy, Stargardt disease, is the most common monogenic inherited retinal disease. Given the pathogenicity of numerous ABCA4 variants is yet to be examined and a significant proportion (more than 15%) of ABCA4 variants are categorized as splice variants in silico, we therefore established a fibroblast-based splice assay to analyze ABCA4 variants in an Australian Stargardt disease cohort and characterize the pathogenic mechanisms of ABCA4 variants. A cohort of 67 patients clinically diagnosed with Stargardt disease was recruited. Genomic DNA was analysed using a commercial panel for ABCA4 variant detection and the consequences of ABCA4 variants were predicted in silico. Dermal fibroblasts were propagated from skin biopsies, total RNA was extracted and the ABCA4 transcript was amplified by RT-PCR. Our analysis identified a total of 67 unique alleles carrying 74 unique variants. The most prevalent splice-affecting complex allele c.[5461-10TC; 5603AT] was carried by 10% of patients in a compound heterozygous state. ABCA4 transcripts from exon 13 to exon 50 were readily detected in fibroblasts. In this region, aberrant splicing was evident in 10 out of 57 variant transcripts (18%), carried by 19 patients (28%). Patient-derived fibroblasts provide a feasible platform for identification of ABCA4 splice variants located within exons 13-50. Experimental evidence of aberrant splicing contributes to the pathogenic classification for ABCA4 variants. Moreover, identification of variants that affect splicing processes provides opportunities for intervention, in particular antisense oligonucleotide-mediated splice correction.

Reported growth rates (GR) of atrophic lesions in Stargardt disease (STGD1) vary widely. In the present study, we report the longitudinal natural history of patients with confirmed biallelic ABCA4 mutations from five genotype groups: c.6079C>T, c.[2588G>C;5603A>T], c.3113C>T, c.5882G>A and c.5603A>T. Fundus autofluorescence (AF) 30° × 30° images were manually segmented for boundaries of definitely decreased autofluorescence (DDAF). The primary outcome was the effective radius GR across five genotype groups. The age of DDAF formation in each eye was calculated using the x-intercept of the DDAF effective radius against age. Discordance between age at DDAF formation and symptom onset was compared. A total of 75 eyes from 39 STGD1 patients (17 male [44%]; mean ± SD age 45 ± 19 years; range 21–86) were recruited. Patients with c.3113C>T or c.6079C>T had a significantly faster effective radius GR at 0.17 mm/year (95% CI 0.12 to 0.22; p < 0.001 and 0.14 to 0.21; p < 0.001) respectively, as compared to those patients harbouring c.5882G>A at 0.06 mm/year (95% CI 0.03–0.09), respectively. Future clinical trial design should consider the effect of genotype on the effective radius GR and the timing of DDAF formation relative to symptom onset.

Retinitis pigmentosa 11 (RP11) is caused by dominant mutations in PRPF31, however a significant proportion of mutation carriers do not develop retinopathy. Here, we investigated the relationship between CNOT3 polymorphism, MSR1 repeat copy number and disease penetrance in RP11 patients and non-penetrant carriers (NPCs). We further characterized PRPF31 and CNOT3 expression in fibroblasts from eight RP11 patients and one NPC from a family carrying the c.1205C&gt, T variant. Retinal organoids (ROs) and retinal pigment epithelium (RPE) were differentiated from induced pluripotent stem cells derived from RP11 patients, an NPC and a control subject. All RP11 patients were homozygous for the 3-copy MSR1 repeat in the PRPF31 promoter, while 3/5 NPCs carried a 4-copy MSR1 repeat. The CNOT3 rs4806718 genotype did not correlate with disease penetrance. PRFP31 expression declined with age in adult cadaveric retina. PRPF31 and CNOT3 expression was reduced in RP11 fibroblasts, RO and RPE compared with controls. Both RP11 and NPC RPE displayed shortened primary cilia compared with controls, however a subpopulation of cells with normal cilia lengths was present in NPC RPE monolayers. Our results indicate that RP11 non-penetrance is associated with the inheritance of a 4-copy MSR1 repeat, but not with CNOT3 polymorphisms.

Mutations in ABCA4 gene are causative for autosomal recessive Stargardt disease (STGD1), the most common inherited retinal dystrophy. Here, we report the generation of an induced pluripotent stem cell (iPSC) line from a STGD1 patient carrying biallelic c.[5461-10T>C;5603A>T];[6077T>C] mutations in the ABCA4 gene. Episomes carrying OCT4, SOX2, KLF4, L-MYC, LIN28 and mp53DD were employed for the reprogramming of patient-derived fibroblasts. This iPSC line expressed comparable pluripotency markers as in a commercially available human iPSC line, displayed normal karyotype and potential for trilineage differentiation, and were negative for both reprogramming episomes and mycoplasma test.

Stargardt disease (STGD1) is the most common inherited retinal dystrophy and ABCA4 c.546-–10 T>C is the most commonly reported splice mutation. Here, we generated and characterized two induced pluripotent stem cell (iPSC) lines from a STGD1 patient with compound heterozygous mutations in ABCA4 (c.[5461-10 T > C;5603A > T];[4163 T > C;455G > A]). Episomal vectors containing OCT4, SOX2, KLF4, L-MYC, LIN28 and mp53DD were employed to conduct the reprogramming of patient-derived fibroblasts. Both lines had a normal karyotype, displayed iPSC morphology, expressed pluripotency markers and showed trilineage differentiation potential. These lines can provide a powerful platform for further investigating the pathophysiological consequences of mutations in ABCA4.

Significance This study develops psychometrically valid item banks across 10 areas of quality of life (QoL) specific to people with hereditary retinal diseases, which will enable clinicians and researchers to explore the impact of hereditary retinal diseases across all aspects of QoL. Purpose The purpose of this study was to assess the psychometric properties of hereditary retinal disease QoL item banks using Rasch analysis and demonstrate the effectiveness of a computerized adaptive testing (CAT) system in obtaining precise measurement of QoL using only a few items. Methods The hereditary retinal disease item banks were answered by 233 participants (median age, 58 years; range, 18 to 94 years; female participants, 59%). The hereditary retinal disease item banks cover 10 QoL domains: activity limitation, mobility, emotional, social, convenience, economic, health concerns, visual symptoms, ocular comfort symptoms, and general symptoms. Rasch analysis assessed the psychometric properties of the 10 item banks and provided item calibrations for the development of CAT. Computerized adaptive testing simulations were performed to calculate the average number of items required to gain precise measurement of each QoL domain. Results The convenience, economic, visual symptoms, and the social domains formed unidimensional scales. However, the activity limitation and health concerns domains demonstrated multidimensionality and required major modifications to resolve this, which resulted in four new QoL domains, namely, reading, driving, lighting, and concerns about the disease progression. In total, 10 item banks underwent CAT simulation testing, which indicated that 8 to 12 items were required to gain precise measurement of each QoL domain. Conclusions We have developed 10 psychometrically valid item banks to measure the QoL domains relevant to people with hereditary retinal diseases. On average, only 5 and 10 items were required to gain measurement at moderate and high precision, respectively.

PURPOSE To establish a mutation-specific age-dependent ultra-widefield fundus autofluorescence (UWF-FAF) trajectory in a large Stargardt disease (STGD1) cohort using total lesion size (TLS) and to develop a clinical method for variant classification. METHODS A retrospective study of patients with biallelic ABCA4 mutations that were evaluated with UWF-FAF. Boundaries of TLS, defined by stippled hyper/hypoautofluorescence, were outlined manually. Pathogenicity was assessed according to ACMG/AMP criteria, and mutation severities were classified based on the current literature. Age-dependent trajectories in TLS were examined in patients with nullizygous, mild, and intermediate mutations. Mutations of uncertain severities were classified using a clinical criterion based on age of symptom onset and TLS. RESULTS Eighty-one patients with STGD1 (mean age = 42 ± 20 years and mean visual acuity = 20/200) were recruited from 65 unrelated families. Patients with biallelic null/severe variants (n = 6) demonstrated an increase in TLS during their second decade reaching a mean ± SD of 796 ± 29 mm2 by age 40. Those harboring mild mutations c.5882G>A or c.5603A>T had lesions confined to the posterior pole with a mean ± SD TLS of 30 ± 39 mm2. Intermediate mutations c.6079C>T or c.[2588G>C;5603A>T] in trans with a null/severe mutation had a mean ± SD TLS of 397 ± 29 mm2. Thirty-two mutations were predicted to cause severe (n = 22), intermediate (n = 6), and mild (n = 5) impairment of ABCA4 function based on age of symptom onset and TLS. CONCLUSION Age-dependent TLS showed unique ABCA4 mutation-specific trajectories. Our novel clinical criterion using age of symptom onset and TLS to segregate ABCA4 mutations into three severity groups requires further molecular studies to confirm its validity.

PRPF31-associated retinopathy (RP11) is a common form of autosomal dominant retinitis pigmentosa (adRP) that exhibits wide variation in phenotype ranging from non-penetrance to early-onset RP. Herein, we report inter-familial and intra-familial variation in the natural history of RP11 using multimodal imaging and microperimetry. Patients were recruited prospectively. The age of symptom onset, best-corrected visual acuity, microperimetry mean sensitivity (MS), residual ellipsoid zone span and hyperautofluorescent ring area were recorded. Genotyping was performed using targeted next-generation and Sanger sequencing and copy number variant analysis. PRPF31 mutations were found in 14 individuals from seven unrelated families. Four disease patterns were observed: (A) childhood onset with rapid progression (N = 4), (B) adult-onset with rapid progression (N = 4), (C) adult-onset with slow progression (N = 4) and (D) non-penetrance (N = 2). Four different patterns were observed in a family harbouring c.267del, patterns B, C and D were observed in a family with c.772_773delins16 and patterns A, B and C were observed in 3 unrelated individuals with large deletions. Our findings suggest that the RP11 phenotype may be related to the wild-type PRPF31 allele rather than the type of mutation. Further studies that correlate in vitro wild-type PRPF31 allele expression level with the disease patterns are required to investigate this association.

Two human iPSC lines were generated from dermal fibroblasts derived from a patient with retinitis pigmentosa caused by CRB1 mutation using episomal plasmids containing OCT4, SOX2, LIN28, KLF4, L-MYC and mp53DD. These clonal iPSC lines carry compound heterozygous mutations in CRB1 (c.2555 T > C and c.3014A > T). Both lines expressed pluripotency markers, displayed a normal karyotype and demonstrated the ability to differentiate into the three primary germ layers, as well as retinal organoids.

Purpose: To investigate atrophy expansion rate (ER) using ultra-widefield (UWF) fundus autofluorescence (FAF) in Stargardt disease (STGD1). Design: Retrospective, longitudinal study. Participants: Patients with biallelic ABCA4 mutations who were evaluated with UWF FAF and Heidelberg 30° × 30° and 55° × 55° FAF imaging. Methods: Patients with atrophy secondary to STGD1 were classified into genotype groups: group A, biallelic severe or null-like variants with early-onset disease; group B, 1 intermediate variant in trans with severe or null-like variant; and group C, 1 mild variant in trans with severe or null-like variant or late-onset disease. The boundaries of definitely decreased autofluorescence (DDAF) were outlined manually and areas (in square millimeters) were recorded at baseline and follow-up. Bland-Altman analysis was conducted to examine agreement between observers and devices. Linear mixed modeling was used to evaluate predictors of ER in DDAF area and square root area (SRA). Main Outcome Measures: Patient and ocular predictors of DDAF area ER and DDAF SRA ER included age at onset, duration of symptoms, genotype group, baseline visual acuity, and baseline atrophy size. Results: A total of 138 eyes from 69 patients (33 men [47%]; mean age ± standard deviation, 41 ± 20 years; range, 10–83 years) carrying 61 unique ABCA4 variants were recruited. Ultra-widefield FAF measurements were equivalent to Heidelberg 30° × 30° imaging. Baseline DDAF area was the only significant predictor of DDAF area ER (P < 0.001). Age at baseline and genotype group were predictors for DDAF SRA ER. Definitely decreased autofluorescence area ER ranged from 4.65 mm2/year (group A) to 0.62 mm2/year (group C). Conclusions: Ultra-widefield FAF is a feasible and reliable method for assessing atrophy ER in STGD1. The value of ABCA4 mutation severity in predicting atrophy ER warrants further investigation.

The human induced pluripotent stem cell (iPSC) lines LEIi015-A and LEIi015-B were derived from a patient with inherited retinal disease caused by compound heterozygous mutations in the SNRNP200 gene (c.[1792C>T];[3341T>C]). Dermal fibroblasts were transfected with episomal plasmids carrying transgenes encoding OCT4, SOX2, KLF4, L-MYC, LIN28, mir302/367 microRNA and shRNA for P53. The clonal iPSC lines LEIi015-A and LEIi015-B expressed iPSC markers, were free from genomic alterations and demonstrated trilineage differentiation potential.

Purpose Biallelic crumbs cell polarity complex component 1 (CRB1) mutations can present as Leber congenital amaurosis (LCA), retinitis pigmentosa (RP), or cystic maculopathy. This study reports a novel phenotype of asymptomatic fenestrated slit maculopathy (AFSM) and examines macular volume profile and microperimetry as clinical trial end points in CRB1-associated retinopathies. Methods Twelve patients from nine families with CRB1 mutation were recruited. Ultra-widefield (UWF) color fundus photography and autofluorescence (AF), spectral-domain optical coherence tomography (SD-OCT), microperimetry, and adaptive optics (AO) imaging were performed. Macular volume profiles were compared with age-matched healthy controls. Genotyping was performed using APEX genotyping microarrays, targeted next-generation sequencing, and Sanger sequencing. Results We identified one patient with LCA, five patients with RP, and four patients with macular dystrophy (MD) with biallelic CRB1 mutations. Two siblings with compound heterozygote genotype (c.[2843G>A]; [498_506del]) had AFSM characterized by localized outer retinal disruption on SD-OCT and parafoveal cone loss on AO imaging despite normal fundus appearance, visual acuity, and foveal sensitivity. UWF AF demonstrated preserved para-arteriolar retinal pigment epithelium (PPRPE) in all patients with RP. Microperimetry documented preserved central retinal function in six patients. The ratio of perifoveal-to-foveal retinal volume was greater than controls in 89% (8/9) of patients with RP or MD, whereas central subfield and total macular volume were outside normal limits in 67% (6/9). Conclusions AO imaging was helpful in detecting parafoveal cone loss in asymptomatic patients. Macular volume profile and microperimetry parameters may have utility as CRB1 trials end points. Translational relevance Macular volume and sensitivity can be used as structural and functional end points for trials on CRB1-associated RP and MD.

Background Mutations in CLN3 cause Batten disease, however non‐syndromic CLN3 disease, characterized by retinal‐specific degeneration, has been also described. Here, we characterized an induced pluripotent stem cell (iPSC)‐derived disease model derived from a patient with non‐syndromic CLN3‐associated retinopathy. Methods Patient‐iPSC, carrying the 1 kb‐deletion and c.175G>A variants in CLN3, coisogenic iPSC, in which the c.175G>A variant was corrected, and control iPSC were differentiated into neural retinal organoids (NRO) and cardiomyocytes. CLN3 transcripts were analyzed by Sanger sequencing. Gene expression was characterized by qPCR and western blotting. NRO were characterized by immunostaining and electron microscopy. Results Novel CLN3 transcripts were detected in adult human retina and control‐NRO. The major transcript detected in patient‐NRO displayed skipping of exons 2 and 4–9. Accumulation of subunit‐C of mitochondrial ATPase (SCMAS) protein was demonstrated in patient‐derived cells. Photoreceptor progenitor cells in patient‐NRO displayed accumulation of peroxisomes and vacuolization of inner segments. Correction of the c.175G>A variant restored CLN3 mRNA and protein expression and prevented SCMAS and inner segment vacuolization. Conclusion Our results demonstrate the expression of novel CLN3 transcripts in human retinal tissues. The c.175G>A variant alters splicing of the CLN3 pre‐mRNA, leading to features consistent with CLN3 deficiency, which were prevented by gene correction., In this paper, we examined the phenotype of retinal organoids derived from a patient with non‐syndromic CLN3 disease. We showed that accumulation of subunit C of mitochondrial ATPase occurs in patient retinal cells and cardiomyocytes, and could be prevented by gene correction. Additionally, we demonstrated that novel CLN3 transcripts are expressed in the human retina.

Choroideremia is an X-linked chorioretinal dystrophy caused by mutations in the CHM gene. Several CHM gene replacement clinical trials are in advanced stages. In this study, we report the molecular confirmation of choroideremia in 14 Australian families sourced from the Australian Inherited Retinal Disease Registry and DNA Bank. Sixteen males (14 symptomatic) and 18 females (4 symptomatic; 14 obligate carriers) were identified for analysis. Participants’ DNA was analyzed for disease-causing CHM variants by Sanger sequencing, TaqMan qPCR and targeted NGS. We report phenotypic and genotypic data for the 14 symptomatic males and four females manifesting disease symptoms. A pathogenic or likely pathogenic CHM variant was detected in all families. Eight variants were previously reported, and five were novel. Two de novo variants were identified. We previously reported the molecular confirmation of choroideremia in 11 Australian families. This study expands the CHM genetically confirmed Australian cohort to 32 males and four affected carrier females., Eye disease: Finding new gene variants for choroideremia Additional variants of the gene responsible for choroideremia, a rare genetic disease that affects blood flow in the eye, have been identified. Choroideremia is X-linked, which means it is much more likely to manifest in males, who do not have a second X chromosome that could carry a functional gene copy. Over time, choroideremia can cause blindness. Terri McLaren at Sir Charles Gairdner Hospital in Perth, Australia, and co-workers aimed to identify new genetic variants that cause choroideremia. Using gene sequencing technology, they identified affected individuals in 14 Australian families, including five new and eight known variants. Prior to sequencing, other eye diseases (excluding choroideremia) had been diagnosed in over one-third of the families, indicating that choroideremia is underdiagnosed. These results will help to build a database of patients for future genetic and other therapies.

Heterozygous c.440 G T mutation in the S-antigen visual arrestinAn observational case series of four family members with adRP. They were examined clinically, with multi-modal retinal imaging and electroretinography (ERG) to ascertain phenotype. Disease progression rate was measured using optical coherence tomography (OCT) and fundus autofluorescence (FAF). A retinal dystrophy panel was used for the proband and cascade testing with targeted Sanger sequencing was conducted in other available family members.The proband presented at 36 years of age with profoundly reduced full-field ERG responses despite a sector RP phenotype. This progressed to a classic RP pattern over several decades leaving a small residual island of central visual field. The horizontal span of the residual outer nuclear layer and the area of hyperautofluorescent ring contracted at a rate of 8-11% and 9-14% per year, respectively. DNA sequencing confirmed the segregation of

Stargardt disease is one of the most common forms of inherited retinal disease and leads to permanent vision loss. A diagnostic feature of the disease is retinal flecks, which appear hyperautofluorescent in fundus autofluorescence (FAF) imaging. The size and number of these flecks increase with disease progression. Manual segmentation of flecks allows monitoring of disease, but is time-consuming. Herein, we have developed and validated a deep learning approach for segmenting these Stargardt flecks (1750 training and 100 validation FAF patches from 37 eyes with Stargardt disease). Testing was done in 10 separate Stargardt FAF images and we observed a good overall agreement between manual and deep learning in both fleck count and fleck area. Longitudinal data were available in both eyes from 6 patients (average total follow-up time 4.2 years), with both manual and deep learning segmentation performed on all (n = 82) images. Both methods detected a similar upward trend in fleck number and area over time. In conclusion, we demonstrated the feasibility of utilizing deep learning to segment and quantify FAF lesions, laying the foundation for future studies using fleck parameters as a trial endpoint.

Autosomal recessive Stargardt disease is the most common cause of inherited retinal disease. In this report, we describe the generation and characterization of two human induced pluripotent stem cell (iPSC) lines from a patient with compound heterozygous mutations in the ABCA4 gene (c.[768G>T];[6079C>T]). Patient dermal fibroblasts were reprogrammed using episomal plasmids encoding OCT4, SOX2, KLF4, L-MYC, LIN28, mir302/367 microRNA and shRNA for P53. The clonal iPSC lines LEIi012-A and LEIi012-B were established. Both lines had a normal karyotype, displayed iPSC morphology, expressed pluripotency genes at similar levels to control iPSC and displayed trilineage differentiation potential during embryoid body differentiation.

Mutations in the splicing factor pre-messenger RNA processing factor 31 (Ophthalmic examination, optical coherence tomography, fundus autofluorescence and microperimetry were performed at baseline and every 6-12 months. Baseline and annual change in best-corrected visual acuity (BCVA), microperimetry mean sensitivity (MS) and number of scotoma loci, residual ellipsoid zone (EZ) span and hyperautofluorescent ring (HAR) area were reported. Next-generation and Sanger sequencing were performed in available members.12 affected members from three generations were examined. Mean (SD, range) age at onset of symptoms was 11 (4.5, 4-19) years. MS declined steadily from the third decade and EZ span and HAR area declined rapidly during the second decade. Serial microperimetry showed negligible change in MS over 2-3 years. However, mean EZ span, near-infrared and short-wavelength HAR area reduction was 203 (6.4%) µm/year, 1.8 (8.7%) mmOur findings suggest that in the studied cohort, the optimal window for therapeutic intervention is the second decade of life and residual EZ span and HAR area can be considered as efficacy outcome measures. Further studies on larger samples with different

The c.1430A G (Asp477Gly) variant in RPE65 has been reported in Irish and Scottish families with either an autosomal dominant retinal dystrophy (adRD) that resembles choroideremia, a vitelliform macular dystrophy or an isolated macular atrophy. We report novel features on multimodal imaging and the natural history of a family harbouring this variant in combination with the BEST1 c.37C T (Arg13Cys) variant.Members of a family with an adRD were examined clinically to ascertain phenotype and underwent genetic testing. Multimodal imaging included widefield colour fundus photography, quantitative autofluorescence (qAF) and spectral domain optical coherence tomography. Electrophysiology and microperimetry were also performed.Vision loss was attributed to foveal atrophy in the proband and choroidal neovascularisation and a vitello-eruptive lesion in one affected son. Peripheral retinal white dots corresponding to subretinal deposits were seen in three patients. The median qAFThe coexistence of the pathogenic BEST1 c.37C T variant may modify clinical features observed in RPE65 adRD. This study expands our understanding of RPE65 adRD as a retinoid cycle disorder supported by the reduced qAF, fine white retinal dots and corresponding subretinal deposits on OCT in affected members.

Background Mutations in the human crumbs homologue 1 (CRB1) gene are associated with a spectrum of inherited retinal diseases. However, functional studies demonstrating the impact of individual CRB1 mutations on gene expression are lacking for most variants. Here, we investigated the effect of two CRB1 variants on pre‐mRNA splicing using neural retinal organoids (NRO) derived from a patient with recessive rod‐cone dystrophy caused by compound heterozygous mutations in CRB1 (c.1892A>G and c.2548G>A). Methods The patient received ophthalmological examinations including multimodal imaging. NRO were differentiated from induced pluripotent stem cells (iPSCs) derived from the patient and a control subject. CRB1 transcripts were characterized by RT‐PCR and Sanger sequencing. Results The Patient displayed retinal thickening with disorganization of retinal layers and preservation of para‐arteriolar retinal pigment epithelium. Both patient and control iPSC produced NRO containing photoreceptor progenitor cells expressing CRB1 mRNA. Patient NRO expressed a novel CRB1 transcript displaying skipping of exon 6. CRB1 transcripts containing the c.2548G>A substitution in exon 7 were expressed in patient NRO. Conclusions Together, these results confirm the pathogenicity of the c.1892A>G and c.2548G>A CRB1 variants in a family with recessive adult‐onset rod‐cone dystrophy and further demonstrate the effects of these variants on pre‐mRNA splicing. This data provide important insights into the pathogenic mechanisms associated with these variants., Here, we demonstrate the pathogenicity of the c.1892A>G and c.2548G>A CRB1 variants in a family with recessive adult‐onset rod‐cone dystrophy and further demonstrate the effects of these variants on pre‐mRNA splicing. In patient‐derived retinal organoids, the c.1892A>G variant was shown to cause exon 6 skipping during CRB1 mRNA splicing, while the c.2548G>A variant results in expression of a CRB1 transcript bearing a missense mutation.

Background Deletion–insertion (delins) variants in the retina‐specific ATP‐binding cassette transporter gene, subfamily A, member 4 (ABCA4) accounts for, This work epitomizes the intrafamilial phenotypic variability in a pseudodominant Stargardt disease pedigree and illustrates the use of patient‐derived fibroblasts to evaluate the effect on splicing of a novel ABCA4 indel variant, and as a method for pathogenicity assessment of other novel ABCA4 variants.

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