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.

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.

Deletion-insertion (delins) variants in the retina-specific ATP-binding cassette transporter gene, subfamily A, member 4 (ABCA4) accounts for <1% in Stargardt disease. The consequences of these delins variants on splicing cannot be predicted with certainty without supporting in vitro data.

Microperimetry is commonly used to assess retinal function. We perform cross-sectional and longitudinal analysis on microperimetry parameters in USH2A retinopathy and explore end points suitable for future clinical trials.

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.

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).

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.

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.

Female carriers of RPGR mutations demonstrate no significant retinal dysfunction or structural change despite a characteristic tapetal-like reflex. In this study, we examined localized changes of pointwise sensitivity (PWS) and cone density (CD) using microperimetry (MP) and adaptive optics (AO) imaging in female carriers of RPGR mutations.

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>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.

Retinitis pigmentosa (RP) is the most common form of inherited blindness, caused by progressive degeneration of photoreceptor cells in the retina, and affects approximately 1 in 3,000 people. Over the past decade, significant progress has been made in gene therapy for RP and related diseases, making genetic characterization increasingly important. Recently, high-throughput technologies have provided an option for reasonably fast, cost-effective genetic characterization of autosomal recessive RP (arRP). The current study used a single nucleotide polymorphism (SNP) genotyping method to exclude up to 28 possible disease-causing genes in 31 non-consanguineous Australian families affected by arRP.

Inherited retinal dystrophies are a clinically and genetically heterogeneous group of disorders. Molecular diagnosis has proven utility for affected individuals. In this study, we report an individual enrolled in the Australian Inherited Retinal Disease Registry and DNA Bank diagnosed with clinical features overlapping between Leber congenital amaurosis and retinitis pigmentosa.

Leber congenital amaurosis (LCA) is a severe visual impairment responsible for infantile blindness, representing ~5% of all inherited retinal dystrophies. LCA encompasses a group of heterogeneous disorders, with 24 genes currently implicated in pathogenesis. Such clinical and genetic heterogeneity poses great challenges for treatment, with personalized therapies anticipated to be the best treatment candidates. Unraveling the individual genetic etiology of disease is a prerequisite for personalized therapies, and could identify potential treatment candidates, inform patient management, and discriminate syndromic forms of disease.

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.