Factors Associated with Large Cup-to-Disc Ratio and Blindness in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) Study.

BACKGROUND/AIMS: Primary open-angle glaucoma (POAG) disproportionately affects individuals of African ancestry. In these patients' eyes, a large cup-to-disc ratio (LCDR > 0.90) suggests greater retinal ganglion cell loss, though these patients often display varied visual ability. This study investigated the prevalence and risk factors associated with LCDR in African ancestry individuals with POAG and explored the differences between blind (>20/200) and not blind (≤20/200) LCDR eyes. METHODS: A case-control methodology was used to investigate the demographic, optic disc, and genetic risk factors of subjects in the Primary Open-Angle African American Glaucoma Genetics Study. Risk factors were analyzed using univariable and multivariable logistic regression models with inter-eye correlation adjusted using generalized estimating equations. RESULTS: Out of 5605 eyes with POAG, 1440 eyes (25.7%) had LCDR. In the multivariable analysis, LCDR was associated with previous glaucoma surgery (OR = 1.72), increased intraocular pressure (OR = 1.04), decreased mean deviation (OR = 1.08), increased pattern standard deviation (OR = 1.06), thinner retinal nerve fiber layer (OR = 1.05), nasalization of vessels (OR = 2.67), bayonetting of vessels (OR = 1.98), visible pores in the lamina cribrosa (OR = 1.68), and a bean-shaped cup (OR = 2.11). Of LCDR eyes, 30.1% were classified as blind (≤20/200). In the multivariable analysis, the statistically significant risk factors of blindness in LCDR eyes were previous glaucoma surgery (OR = 1.72), increased intraocular pressure (OR = 1.05), decreased mean deviation (OR = 1.04), and decreased pattern standard deviation (OR = 0.90). CONCLUSIONS: These findings underscore the importance of close monitoring of intraocular pressure and visual function in African ancestry POAG patients, particularly those with LCDR, to preserve visual function.

Legg-Calve-Perthes' disease: an opportunity to prevent blindness?

Legg-Calve-Perthes' disease (LCP) is defined as avascular necrosis of the femoral head in a child and may present to a variety of disciplines from general practice to orthopaedics, paediatrics, rheumatology and more. The Stickler syndromes are a group of disorders of type II, IX and XI collagen associated with hip dysplasia, retinal detachment, deafness and cleft palate. The pathogenesis of LCP disease remains an enigma but there have been a small number of cases reporting variants in the gene encoding the α1 chain of type II collagen (COL2A1). Variants in COL2A1 are known to cause type 1 Stickler syndrome (MIM 108300, 609508), which is a connective tissue disorder with a very high risk of childhood blindness, and it is also associated with dysplastic development of the femoral head. It is unclear whether COL2A1 variants make a definitive contribution to both disorders, or whether the two are indistinguishable using current clinical diagnostic techniques. In this paper, we compare the two conditions and present a case series of 19 patients with genetically confirmed type 1 Stickler syndrome presenting with a historic diagnosis of LCP. In contrast to isolated LCP, children with type 1 Stickler syndrome have a very high risk of blindness from giant retinal tear detachment, but this is now largely preventable if a timely diagnosis is made. This paper highlights the potential for avoidable blindness in children presenting to clinicians with features suggestive of LCP disease but with underlying Stickler syndrome and proposes a simple scoring system to assist clinicians.

Gata2a Mutation Causes Progressive Microphthalmia and Blindness in Nile Tilapia.

The normal development of lens fiber cells plays a critical role in lens morphogenesis and maintaining transparency. Factors involved in the development of lens fiber cells are largely unknown in vertebrates. In this study, we reported that GATA2 is essential for lens morphogenesis in Nile tilapia (Oreochromis niloticus). In this study, Gata2a was detected in the primary and secondary lens fiber cells, with the highest expression in primary fiber cells. gata2a homozygous mutants of tilapia were obtained using CRISPR/Cas9. Different from fetal lethality caused by Gata2/gata2a mutation in mice and zebrafish, some gata2a homozygous mutants of tilapia are viable, which provides a good model for studying the role of gata2 in non-hematopoietic organs. Our data showed that gata2a mutation caused extensive degeneration and apoptosis of primary lens fiber cells. The mutants exhibited progressive microphthalmia and blindness in adulthood. Transcriptome analysis of the eyes showed that the expression levels of almost all genes encoding crystallin were significantly down-regulated, while the expression levels of genes involved in visual perception and metal ion binding were significantly up-regulated after gata2a mutation. Altogether, our findings indicate that gata2a is required for the survival of lens fiber cells and provide insights into transcriptional regulation underlying lens morphogenesis in teleost fish.

Update on Viral Gene Therapy Clinical Trials for Retinal Diseases.

In 2001, the first large animal was successfully treated with a gene therapy that restored its vision. Lancelot, the Briard dog that was treated, suffered from a human childhood blindness called Leber's congenital amaurosis type 2. Sixteen years later, the gene therapy was approved by the U.S. Food and Drug Administration. The success of this gene therapy in dogs led to a fast expansion of the ocular gene therapy field. By now every class of inherited retinal dystrophy has been treated in at least one animal model and many clinical trials have been initiated in humans. In this study, we review the status of viral gene therapies for the retina, with a focus on ongoing human clinical trials. It is likely that in the next decade we will see several new viral gene therapies approved.

Insight from OPN1LW Gene Haplotypes into the Cause and Prevention of Myopia.

Nearsightedness (myopia) is a global health problem of staggering proportions that has driven the hunt for environmental and genetic risk factors in hopes of gaining insight into the underlying mechanism and providing new avenues of intervention. Myopia is the dominant risk factor for leading causes of blindness, including myopic maculopathy and retinal detachment. The fundamental defect in myopia-an excessively elongated eyeball-causes blurry distance vision that is correctable with lenses or surgery, but the risk of blindness remains. Haplotypes of the long-wavelength and middle-wavelength cone opsin genes (OPN1LW and OPN1MW, respectively) that exhibit profound exon-3 skipping during pre-messenger RNA splicing are associated with high myopia. Cone photoreceptors expressing these haplotypes are nearly devoid of photopigment. Conversely, cones in the same retina that express non-skipping haplotypes are relatively full of photopigment. We hypothesized that abnormal contrast signals arising from adjacent cones differing in photopigment content stimulate axial elongation, and spectacles that reduce contrast may significantly slow myopia progression. We tested for an association between spherical equivalent refraction and OPN1LW haplotype in males of European ancestry as determined by long-distance PCR and Sanger sequencing and identified OPN1LW exon 3 haplotypes that increase the risk of common myopia. We also evaluated the effects of contrast-reducing spectacles lenses on myopia progression in children. The work presented here provides new insight into the cause and prevention of myopia progression.

Intravitreal antisense oligonucleotide sepofarsen in Leber congenital amaurosis type 10: a phase 1b/2 trial.

CEP290-associated Leber congenital amaurosis type 10 (LCA10) is a retinal disease resulting in childhood blindness. Sepofarsen is an RNA antisense oligonucleotide targeting the c.2991+1655A>G variant in the CEP290 gene to treat LCA10. In this open-label, phase 1b/2 ( NCT03140969 ), 12-month, multicenter, multiple-dose, dose-escalation trial, six adult patients and five pediatric patients received ≤4 doses of intravitreal sepofarsen into the worse-seeing eye. The primary objective was to evaluate sepofarsen safety and tolerability via the frequency and severity of ocular adverse events (AEs); secondary objectives were to evaluate pharmacokinetics and efficacy via changes in functional outcomes. Six patients received sepofarsen 160 µg/80 µg, and five patients received sepofarsen 320 µg/160 µg. Ten of 11 (90.9%) patients developed ocular AEs in the treated eye (5/6 with 160 µg/80 µg; 5/5 with 320 µg/160 µg) versus one of 11 (9.1%) in the untreated eye; most were mild in severity and dose dependent. Eight patients developed cataracts, of which six (75.0%) were categorized as serious (2/3 with 160 µg/80 µg; 4/5 with 320 µg/160 µg), as lens replacement was required. As the 160-µg/80-µg group showed a better benefit-risk profile, higher doses were discontinued or not initiated. Statistically significant improvements in visual acuity and retinal sensitivity were reported (post hoc analysis). The manageable safety profile and improvements reported in this trial support the continuation of sepofarsen development.

Engineered virus-like particles for efficient in vivo delivery of therapeutic proteins.

Methods to deliver gene editing agents in vivo as ribonucleoproteins could offer safety advantages over nucleic acid delivery approaches. We report the development and application of engineered DNA-free virus-like particles (eVLPs) that efficiently package and deliver base editor or Cas9 ribonucleoproteins. By engineering VLPs to overcome cargo packaging, release, and localization bottlenecks, we developed fourth-generation eVLPs that mediate efficient base editing in several primary mouse and human cell types. Using different glycoproteins in eVLPs alters their cellular tropism. Single injections of eVLPs into mice support therapeutic levels of base editing in multiple tissues, reducing serum Pcsk9 levels 78% following 63% liver editing, and partially restoring visual function in a mouse model of genetic blindness. In vitro and in vivo off-target editing from eVLPs was virtually undetected, an improvement over AAV or plasmid delivery. These results establish eVLPs as promising vehicles for therapeutic macromolecule delivery that combine key advantages of both viral and nonviral delivery.

A novel frameshift c.22_25dupGCAT mutation of the NDP gene in a Chinese infant with Norrie disease: A case report.

RATIONALE: Norrie disease (ND) is a rare X-linked recessive disease characterized by bilateral congenital blindness and auditory impairments. According to the previous studies, Norrin cystine knot growth factor (NDP) gene have been found to be responsible for ND. Herein, we report a case of ND with a novel mutation in NDP and elucidate the clinical and molecular characteristics of this patient. PATIENT CONCERNS: A 2-month-old Chinese male infant presented with gray-white opacification in the bilateral cornea. Vitreous opacity and retinal detachment were observed on ocular ultrasound. Furthermore, a novel de novo hemizygous mutation (c.22_25dupGCAT, p.S9Cfs∗18) in exon 2 of the NDP gene was identified by next-generation sequencing. SWISS-MODEL predicted that the c.22_25dupGCAT mutation truncated the NDP protein. DIAGNOSIS: Based on the above clinical and genetic evidence, this patient was eventually diagnosed with ND. INTERVENTIONS: Currently, no clinical therapy is available for ND. OUTCOMES: In addition to the typical ocular symptoms, no other abnormalities were observed. The patient's vital signs remained stable and normal. LESSON: A novel causative mutation of NDP was identified using next-generation sequencing. Our report expands the pathogenic mutation spectrum of NDP and facilitates genetic counseling and prenatal diagnosis. Additionally, we emphasize the importance of molecular genetic testing in the diagnosis of ND.

Association of the CYP39A1 G204E Genetic Variant with Increased Risk of Glaucoma and Blindness in Patients with Exfoliation Syndrome.

PURPOSE: Carriers of functionally deficient mutations in the CYP39A1 gene have been recently reported to have a 2-fold increased risk of exfoliation syndrome (XFS). The aim of this study was to evaluate the risk of blindness and related clinical phenotypes of XFS patients carrying the loss-of-function CYP39A1 G204E mutation in comparison with XFS patients without any CYP39A1 mutation. DESIGN: Retrospective case study. PARTICIPANTS: A total of 35 patients diagnosed with XFS carrying the CYP39A1 G204E mutation and 150 XFS patients without any CYP39A1 mutation who were randomly selected from the Japanese XFS cohort. METHODS: Two-sided Fisher exact test with an alpha level < 0.05 was used to estimate the significance of the calculated odds ratio (OR) for all categorical measures. Comparisons between groups of subjects were performed using linear mixed effect models with group as random effect and taking possible dependence between eyes within a subject into account. MAIN OUTCOME MEASURES: Primary analysis compared the incidence of blindness (defined as visual acuity [VA] < 0.05 decimal), prevalence of exfoliation glaucoma (XFG), history of glaucoma surgery, and indices of glaucoma severity such as visual field (VF) mean deviation (MD), intraocular pressure (IOP), and vertical cup-disc ratio (CDR) between CYP39A1 G204E carriers and those without any CYP39A1 mutation. RESULTS: The overall risk for blindness was significantly higher in XFS patients carrying the CYP39A1 G204E variant (10/35 [28.6%]) compared with XFS patients without any CYP39A1 mutations (8/150 [5.4%]; odds ratio [OR], 7.1; 95% confidence interval [CI], 2.7-20.2]; P < 0.001). A higher proportion of XFS patients with the CYP39A1 G204E mutation (23/35 [65.7%]) had evidence of XFG in at least 1 eye compared with the comparison group (41/150 [27.3%]; OR, 5.1; 95% CI, 2.4-11.4]; P < 0.0001). Significantly higher peak IOP, larger vertical CDR, and worse VF MD were also found in CYP39A1 G204E variant carriers (P < 0.001). Additionally, patients with the CYP39A1 G204E mutation (18/35 [51.4%]) required more laser or glaucoma surgical interventions compared with those without any CYP39A1 mutation (32/150 [21.3%], P < 0.001). CONCLUSIONS: Patients with XFS carrying the CYP39A1 G204E mutation had significantly increased risk of blindness, higher occurrence of XFG, and more severe glaucoma compared with patients with XFS without any CYP39A1 mutation.

Gene therapy: perspectives from young adults with Leber's congenital amaurosis.

AIMS/PURPOSE: To investigate Leber congenital amaurosis (LCA) patients' expectations, decision-making processes and gene therapy-related concerns. METHODS: Using a qualitative approach, we explored perceptions of gene therapy and clinical trials among individuals with LCA. Young adults with a clinical diagnosis of LCA were recruited through the Ocular Genetics Programme at the Hospital for Sick Children. Semi-structured interviews were conducted with ten patients and analysed following the principles of qualitative description. RESULTS: Study participants were aware of ongoing gene therapy research trials and actively sought information regarding advances in ophthalmology and vision restoration. The majority of participants would enrol or were enrolled in a gene-replacement therapy trial, while a minority was ambivalent or would not enrol if provided an opportunity. Participants attributed different values to clinical trials, which influenced their willingness to participate. Intrinsic factors related to coping, adaptation to vision loss and resilience also influenced decision-making. DISCUSSION: This study highlights the complex factors involved in gene-therapy-related decision-making and acts as a proponent for adopting patient-centred care strategies when counselling individuals considering gene therapy or clinical trial participation.

Leber's Congenital Amaurosis: Current Concepts of Genotype-Phenotype Correlations.

Leber's congenital amaurosis (LCA), one of the most severe inherited retinal dystrophies, is typically associated with extremely early onset of visual loss, nystagmus, and amaurotic pupils, and is responsible for 20% of childhood blindness. With advances in molecular diagnostic technology, the knowledge about the genetic background of LCA has expanded widely, while disease-causing variants have been identified in 38 genes. Different pathogenetic mechanisms have been found among these varieties of genetic mutations, all of which result in the dysfunction or absence of their encoded proteins participating in the visual cycle. Hence, the clinical phenotypes also exhibit extensive heterogenicity, including the course of visual impairment, involvement of the macular area, alteration in retinal structure, and residual function of the diseased photoreceptor. By reviewing the clinical course, fundoscopic images, optical coherent tomography examination, and electroretinogram, genotype-phenotype correlations could be established for common genetic mutations in LCA, which would benefit the timing of the diagnosis and thus promote early intervention. Gene therapy is promising in the management of LCA, while several clinical trials are ongoing and preliminary success has been announced, focusing on RPE65 and other common disease-causing genes. This review provides an update on the genetics, clinical examination findings, and genotype-phenotype correlations in the most well-established causative genetic mutations of LCA.

Identification of a variant in NDP associated with X-linked retinal dysplasia in the English cocker spaniel dog.

PURPOSE: Three related male English Cocker Spaniels (ECS) were reported to be congenitally blind. Examination of one of these revealed complete retinal detachment. A presumptive diagnosis of retinal dysplasia (RD) was provided and pedigree analysis was suggestive of an X-linked mode of inheritance. We sought to investigate the genetic basis of RD in this family of ECS. METHODS: Following whole genome sequencing (WGS) of the one remaining male RD-affected ECS, two distinct investigative approaches were employed: a candidate gene approach and a whole genome approach. In the candidate gene approach, COL9A2, COL9A3, NHEJ1, RS1 and NDP genes were investigated based on their known associations with RD and retinal detachment in dogs and humans. In the whole genome approach, affected WGS was compared with 814 unaffected canids to identify candidate variants, which were filtered based on appropriate segregation and predicted pathogenic effects followed by subsequent investigation of gene function. Candidate variants were tested for appropriate segregation in the ECS family and association with disease was assessed using samples from a total of 180 ECS. RESULTS: The same variant in NDP (c.653_654insC, p.Met114Hisfs*16) that was predicted to result in 15 aberrant amino acids before a premature stop in norrin protein, was identified independently by both approaches and was shown to segregate appropriately within the ECS family. Association of this variant with X-linked RD was significant (P = 0.0056). CONCLUSIONS: For the first time, we report a variant associated with canine X-linked RD. NDP variants are already known to cause X-linked RD, along with other abnormalities, in human Norrie disease. Thus, the dog may serve as a useful large animal model for research.

Norrie disease with a spontaneously shrinking choroid plexus abnormality: a case report.

Background: Norrie disease is a genetic disorder of the retina characterized by impaired retinal vascular development leading to retinal detachment and blindness. Non-retinal manifestations of the disorder include intellectual disability and seizure disorders. However, to date, no association with neurological mass lesions has been described.Materials and methods: Case reporResults: Here, we report a case of a patient with Norrie disease who presented with an enhancing mass of the choroid plexus that spontaneously diminished in size. Conclusion: This report suggests watchful waiting as a reasonable clinical approach to choroid plexus lesions in patients with Norrie disease.

Function and regulation of the Spt-Ada-Gcn5-Acetyltransferase (SAGA) deubiquitinase module.

The Spt-Ada-Gcn5 Acetyltransferase (SAGA) chromatin modifying complex is a critical regulator of gene expression and is highly conserved across species. Subunits of SAGA arrange into discrete modules with lysine aceyltransferase and deubiquitinase activities housed separately. Mutation of the SAGA deubiquitinase module can lead to substantial biological misfunction and diseases such as cancer, neurodegeneration, and blindness. Here, we review the structure and functions of the SAGA deubiquitinase module and regulatory mechanisms acting to control these.

Frecuencia del polimorfismo genético ACTN3 R577X y ECA I/D en atletas ciegos de fútbol 5 / Frequency of genetic polymorphism ACTN3 R577X and ACE I/D in blind athletes of 5-a-side football

RESUMEN: El objetivo de este estudio fue describir la frecuencia genotípica y alélica del ACTN3 R577X y ECA I/D en atletas ciegos de fútbol 5. Se incluyó una metodología descriptiva con una muestra de 63 deportistas ciegos (28,0±5,8 años), todos varones, de equipos de fútbol 5 de alto rendimiento. El polimorfismo se determinó mediante la reacción en cadena de la polimerasa en tiempo real (RT-PCR). La estadística fue descriptiva realizada a partir de las medidas de frecuencia de genotipos y alelos. La frecuencia genotípica de la ACTN3 en los deportistas presentó la siguiente distribución: el 28,6 % con genotipo RR, el 54 % con RX y el 17,4 % con XX y frecuencia alélica del 55,6 % para el alelo R y del 44,4 % para el alelo X. En cuanto a la ECA I/D, la frecuencia genotípica fue del 63,5 % para el genotipo ID, del 22,2 % para el DD y del 14,3 % para el II. La frecuencia alélica presentó prevalencia del alelo D con el 53,9 %. El estudio constató una predominancia de los genotipos y alelos representativos de las modalidades de fuerza y velocidad para ACTN3 R577X y ECA I/D de atletas de fútbol 5.

SUMMARY: The aim of this study was to describe the genotypic and allele frequency of ACTN3 R577X and ACE I/D in blind athletes of 5-a-side football performance. A descriptive methodology was included with a sample of 63 blind male athletes (28.0 ±5.8 years) of football teams with a 5-a-side performance rating. The polymorphism was determined by means by of real-time Polymerase Chain Reaction (rt-PCR). Statistics were descriptive based on the measures of frequency of genotypes and alleles. The genotypic frequency of ACTN3 by the athletes presented the following distribution: 28.6 % with RR genotype, 54 % with RX and 17.4 % XX and allele frequency of 55.6 % for the R allele and 44.4 % for the X allele. As for ACE I/D, the genotype frequency was 63.5 % for genotype ID, 22.2 % for DD and 14.3 % for II. The allele frequency showed a predominance of the D allele with 53.9 %. The study found for ACTN3 R577X and ACE I/ D of blind athletes of 5-a-side football, a predominance of genotypes and alleles representative of strength and speed modalities.

A gene therapy for inherited blindness using dCas9-VPR-mediated transcriptional activation.

Catalytically inactive dCas9 fused to transcriptional activators (dCas9-VPR) enables activation of silent genes. Many disease genes have counterparts, which serve similar functions but are expressed in distinct cell types. One attractive option to compensate for the missing function of a defective gene could be to transcriptionally activate its functionally equivalent counterpart via dCas9-VPR. Key challenges of this approach include the delivery of dCas9-VPR, activation efficiency, long-term expression of the target gene, and adverse effects in vivo. Using dual adeno-associated viral vectors expressing split dCas9-VPR, we show efficient transcriptional activation and long-term expression of cone photoreceptor-specific M-opsin (Opn1mw) in a rhodopsin-deficient mouse model for retinitis pigmentosa. One year after treatment, this approach yields improved retinal function and attenuated retinal degeneration with no apparent adverse effects. Our study demonstrates that dCas9-VPR-mediated transcriptional activation of functionally equivalent genes has great potential for the treatment of genetic disorders.

Novel mutation identified in Leber congenital amaurosis - a case report.

BACKGROUND: Leber congenital amaurosis (LCA) is the earliest onset and the most severe form of all inherited retinal degenerative disorders, characterized by blindness, or severe visual impairment from birth, and typically exhibits clinical and genetic heterogeneity. Recently, 14 causative genes of LCA were reported. We performed whole-exome sequencing (WES) for Japanese siblings, and identified a novel homozygous nonsense mutation in the RPGR-interacting protein 1 (RPGRIP1) gene. We also report their follow-up data over 27 years. CASE PRESENTATION: Patient 1 is a 37-year-old male. In 1992, his eye position indicated orthophoria, however, horizontal nystagmus was evident, and he complained of photophobia. His best corrected decimal visual acuity (BCVA) was 0.2 (S + 6.5/C-3.5/170°) OD and 0.1 (S + 6.0/C-2.5/10°) OS. Fundus examination revealed bisymmetrical inferior focal retinal pigment epithelium (RPE) mottling. Bright-flash electroretinogram (ERG) revealed a subnormal pattern, while 30 Hz flicker ERG was non-recordable in both eyes. At his final visit in 2019, his BCVA was 0.09 (S + 3.5/C-3.5/180°) OD and 0.09 (S + 3.0/C-4.0/10°) OS. Patient 2, a 34-year-old female, is the sibling of patient 1. In 1992, her BCVA was 0.05 (S + 6.0) OD and 0.06 (S + 5.0) OS. She was in a chin-up position during visual acuity testing. Horizontal nystagmus was evident, and she also complained of photophobia. Bright-flash ERG was severely attenuated, and 30 Hz flicker ERG was non-recordable in both eyes. At her final visit in 2019, her BCVA was 0.02 (uncorrectable) OD and 0.03 (uncorrectable) OS. There were no other patients with LCA in their family and their parents were non-consanguineous. WES revealed a homozygous, consecutive, two-nucleotide variation in the RPGRIP1 gene (NM_020366: exon15:c.G2294A and c.C2295A, p.C765X), resulting in a premature stop codon. We interpreted this variation as a novel pathogenic mutation of RPGRIP1 that contributes to LCA6 development. CONCLUSIONS: Herein, we report a novel nonsense mutation of RPGRIP1 in two patients with LCA6 and present their long-term follow-up data. These clinical data linked to genotypes provide important information for the development of new treatments, such as gene therapy, as well as for genetic counseling.

Loss of CLN3, the gene mutated in juvenile neuronal ceroid lipofuscinosis, leads to metabolic impairment and autophagy induction in retinal pigment epithelium.

Juvenile neuronal ceroid lipofuscinosis (JNCL, aka. juvenile Batten disease or CLN3 disease) is a lysosomal storage disease characterized by progressive blindness, seizures, cognitive and motor failures, and premature death. JNCL is caused by mutations in the Ceroid Lipofuscinosis, Neuronal 3 (CLN3) gene, whose function is unclear. Although traditionally considered a neurodegenerative disease, CLN3 disease displays eye-specific effects: Vision loss not only is often one of the earliest symptoms of JNCL, but also has been reported in non-syndromic CLN3 disease. Here we described the roles of CLN3 protein in maintaining healthy retinal pigment epithelium (RPE) and normal vision. Using electroretinogram, fundoscopy and microscopy, we showed impaired visual function, retinal autofluorescent lesions, and RPE disintegration and metaplasia/hyperplasia in a Cln3 ~ 1 kb-deletion mouse model [1] on C57BL/6J background. Utilizing a combination of biochemical analyses, RNA-Seq, Seahorse XF bioenergetic analysis, and Stable Isotope Resolved Metabolomics (SIRM), we further demonstrated that loss of CLN3 increased autophagic flux, suppressed mTORC1 and Akt activities, enhanced AMPK activity, and up-regulated gene expression of the autophagy-lysosomal system in RPE-1 cells, suggesting autophagy induction. This CLN3 deficiency induced autophagy induction coincided with decreased mitochondrial oxygen consumption, glycolysis, the tricarboxylic acid (TCA) cycle, and ATP production. We also reported for the first time that loss of CLN3 led to glycogen accumulation despite of impaired glycogen synthesis. Our comprehensive analyses shed light on how loss of CLN3 affect autophagy and metabolism. This work suggests possible links among metabolic impairment, autophagy induction and lysosomal storage, as well as between RPE atrophy/degeneration and vision loss in JNCL.

A novel c.287G>T NDP missense mutation in a Chinese family with Norrie disease.

BACKGROUND: Norrie disease is a rare X-linked recessive disorder in affected males. The typical features are congenital blindness, progressive hearing impairment, and, in some cases, some degree of mental retardation, microphthalmia, microcornea, growth failure, and seizures. Norrie disease is caused by mutations in the Norrie disease pseudoglioma gene (NDP), which encodes the Norrin protein that plays a crucial role in vascular development, neural cell differentiation, and proliferation in the retina and cerebellum. The aim of the present study was to identify the genetic cause of the disease and the phenotypic characteristics of the patients in an affected Chinese family. MATERIALS AND METHODS: A Chinese family with Norrie disease was studied, and clinical phenotypes of the proband were observed. With informed consent from the patients' family, blood samples from family members were collected, genomic DNA was extracted, and Sanger sequencing was performed to identify the disease-causing mutation. RE: sults: The c.287 G > T mutation of NDP was identified by Sanger sequencing and resulted in p.Cys96Phe. The pathogenicity prediction was performed by MutationTaster, Polyphen-2, SIFT, and PROVEAN, all of which suggested that the mutation is disease-causing and may be responsible for the phenotypes of Norrie disease. CONCLUSION: The c.287 G > T of NDP is a novel mutation responsible for Norrie disease in a Chinese family.

Pharmacological restoration of visual function in a zebrafish model of von-Hippel Lindau disease.

Von Hippel-Lindau (VHL) syndrome is a rare, autosomal dominant disorder, characterised by hypervascularised tumour formation in multiple organ systems. Vision loss associated with retinal capillary hemangioblastomas remains one of the earliest complications of VHL disease. The mortality of Vhl-/- mice in utero restricted modelling of VHL disease in this mammalian model. Zebrafish harbouring a recessive germline mutation in the vhl gene represent a viable, alternative vertebrate model to investigate associated ocular loss-of-function phenotypes. Previous studies reported neovascularisation of the brain, eye and trunk together with oedema in the vhl-/- zebrafish eye. In this study, we demonstrate vhl-/- zebrafish almost entirely lack visual function. Furthermore, hyaloid vasculature networks in the vhl-/- eye are improperly formed and this phenotype is concomitant with development of an ectopic intraretinal vasculature. Sunitinib malate, a multi tyrosine kinase inhibitor, market authorised for cancer, reversed the ocular behavioural and morphological phenotypes observed in vhl-/- zebrafish. We conclude that the zebrafish vhl gene contributes to an endogenous molecular barrier that prevents development of intraretinal vasculature, and that pharmacological intervention with sunitinib can improve visual function and hyaloid vessel patterning while reducing abnormally formed ectopic intraretinal vessels in vhl-/- zebrafish.