The first gene therapy for RPE65 biallelic dystrophy with voretigene neparvovec-rzyl in Brazil.

PURPOSE: To report the first Brazilian patient with RPE65 deficiency-inherited retinal dystrophy (RPE65-IRD) treated with voretigene neparvovec-rzyl (VN). METHODS: An adult patient with Leber congenital amaurosis-2 with a homozygous mutation in the RPE65 gene (p.Phe83Leu) was treated bilaterally with VN. The clinical and surgical aspects are described. The baseline and 4-month postoperative ophthalmologic examinations included measurement of the best-corrected visual acuity (BCVA), full-field stimulus threshold (FST) test, Octopus 900 semiautomated kinetic visual fields (VFs), and microperimetry. RESULTS: No complications developed in this patient. The BCVA remained stable. The full-field stimulus threshold test (FST) and VFs showed clinically significant improvements bilaterally. The patient reported significant improvements in the ability to perform daily activities, mainly for those requiring the VFs and vision in a low-luminescence environment. CONCLUSIONS: The treatments were beneficial for this patient who was homozygous for RPE65 p.Phe83Leu. The first VN treatments in an adult Brazilian patient in clinical practice showed measurable improvements in visual outcomes that were meaningful for the patient's daily activities. TRANSLATIONAL RELEVANCE: This case reinforces the clinical trial results and proves that the procedure is feasible in countries such as Brazil.

Epidemiology of Mutations in the 65-kDa Retinal Pigment Epithelium (RPE65) Gene-Mediated Inherited Retinal Dystrophies: A Systematic Literature Review.

INTRODUCTION: Inherited retinal dystrophies (IRDs) represent a genetically diverse group of progressive, visually debilitating diseases. Adult and paediatric patients with vision loss due to IRD caused by biallelic mutations in the 65-kDa retinal pigment epithelium (RPE65) gene are often clinically diagnosed as retinitis pigmentosa (RP), and Leber congenital amaurosis (LCA). This study aimed to understand the epidemiological landscape of RPE65 gene-mediated IRD through a systematic review of the literature, as the current evidence base for its epidemiology is very limited. METHODS: Medline, Embase, and other databases were searched for articles on the epidemiology of RPE65 gene-mediated IRDs from inception until June 2021. Studies were included if they were original research articles reporting the epidemiology of RP and LCA and/or proportion of RPE65 gene mutations in these clinically diagnosed or molecularly confirmed IRDs patients. RESULTS: A total of 100 studies with relevant data were included in this systematic review. The range for prevalence of LCA and RP in the literature was 1.20-2.37 and 11.09-26.43 per 100,000, respectively. The proportion of RPE65 mutations in clinically diagnosed patients with LCA was found to be between ~ 2-16% within the US and major European countries (France, Germany, Italy, Spain, and the UK). This range was also comparable to our findings in the Asian region for RPE65-LCA (1.26-16.67%). Similarly, for these European countries, RPE65-RP was estimated between 0.23 and 1.94%, and RPE65-IRD range was 1.2-14%. Further, in the Americas region, mutations in RPE65 were reported to cause 1-3% of RP and 0.8-3.7% of IRD cases. Lastly, the RPE65-IRD range was 4.81-8% in the Middle East region. CONCLUSIONS: There are significant variations in reporting of RPE65 proportions within countries as well as regions. Generating robust epidemiological evidence on RPE65 gene-mediated IRDs would be fundamental to support rare disease awareness, timely therapeutic intervention, and public health decision-making.

Analysis of an NGS retinopathy panel detects chromosome 1 uniparental isodisomy in a patient with RPE65-related leber congenital amaurosis.

Purpose: This study aims to demonstrate the possibility of detecting segmental uniparental isodisomy (iUPD) using a next-generation sequencing gene panel by reporting a Leber congenital amaurosis (LCA) case caused by a homozygous pathogenic variant in RPE65 (c.1022 T > C:p.Leu341Ser) inherited exclusively from the proband's mother.Methods: Samples from the trio (proband, mother, and father) were sequenced with a next-generation sequencing (NGS) retinopathy gene panel (224 genes) and the VCF file containing all variants was used in order to determine single nucleotide variant (SNV) counts from each sample across all chromosomes.Results: Trio analysis showed that of 81 Chr1 inherited variants 41 were exclusively maternal, including 21 homozygous. The other 40 variants were common to both parents. On remaining autosomal chromosomes (Chr2-22) 645 inherited variants were found, 147 of them were exclusively maternal and 132 exclusively paternal. Based on these NGS data, it was possible to note that the proband's chromosomes 1 are more similar to his mother's chromosome 1 than his father's, suggesting the pathogenic homozygous variant found in this patient was inherited exclusively from the mother due to uniparental maternal isodisomy.Conclusions: This study presents a secondary analysis pipeline to identify responsible variants for a phenotype and the correct inheritance pattern, which is a critical step to the proper and accurate genetic counseling of all family members. In addition, this approach could be used to determine iUPD in different Mendelian disorders if the sequencing panel identifies variants spread throughout the genome.

Extensive genic and allelic heterogeneity underlying inherited retinal dystrophies in Mexican patients molecularly analyzed by next-generation sequencing.

BACKGROUND: Retinal dystrophies (RDs) are one of the most genetically heterogeneous monogenic disorders with ~270 associated loci identified by early 2019. The recent application of next-generation sequencing (NGS) has greatly improved the molecular diagnosis of RD patients. Genetic characterization of RD cohorts from different ethnic groups is justified, as it would improve the knowledge of molecular basis of the disease. Here, we present the results of genetic analysis in a large cohort of 143 unrelated Mexican subjects with a variety of RDs. METHODS: A targeted NGS approach covering 199 RD genes was employed for molecular screening of 143 unrelated patients. In addition to probands, 258 relatives were genotyped by Sanger sequencing for familial segregation of pathogenic variants. RESULTS: A solving rate of 66% (95/143) was achieved, with evidence of extensive loci (44 genes) and allelic (110 pathogenic variants) heterogeneity. Forty-eight percent of the identified pathogenic variants were novel while ABCA4, CRB1, USH2A, and RPE65 carried the greatest number of alterations. Novel deleterious variants in IDH3B and ARL6 were identified, supporting their involvement in RD. Familial segregation of causal variants allowed the recognition of 124 autosomal or X-linked carriers. CONCLUSION: Our results illustrate the utility of NGS for genetic diagnosis of RDs of different populations for a better knowledge of the mutational landscape associated with the disease.

Pathogenicity Reclasssification of RPE65 Missense Variants Related to Leber Congenital Amaurosis and Early-Onset Retinal Dystrophy.

A challenge in molecular diagnosis and genetic counseling is the interpretation of variants of uncertain significance. Proper pathogenicity classification of new variants is important for the conclusion of molecular diagnosis and the medical management of patient treatments. The purpose of this study was to reclassify two RPE65 missense variants, c.247T>C (p.Phe83Leu) and c.560G>A (p.Gly187Glu), found in Brazilian families. To achieve this aim, we reviewed the sequencing data of a 224-gene retinopathy panel from 556 patients (513 families) with inherited retinal dystrophies. Five patients with p.Phe83Leu and seven with p.Gly187Glu were selected and their families investigated. To comprehend the pathogenicity of these variants, we evaluated them based on the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) classification guidelines. Initially, these RPE65 variants met only three pathogenic criteria: (i) absence or low frequency in the population, (ii) several missense pathogenic RPE65 variants, and (iii) 15 out of 16 lines of computational evidence supporting them as damaging, which together allowed the variants to be classified as uncertain significance. Two other pieces of evidence were accepted after further analysis of these Brazilian families: (i) p.Phe83Leu and p.Gly187Glu segregate with childhood retinal dystrophy within families, and (ii) their prevalence in Leber congenital amaurosis (LCA)/early-onset retinal dystrophy (EORD) patients can be considered higher than in other inherited retinal dystrophy patients. Therefore, these variants can now be classified as likely pathogenic according to ACMG/AMP classification guidelines.

A high prevalence of biallelic RPE65 mutations in Costa Rican children with Leber congenital amaurosis and early-onset retinal dystrophy.

BACKGROUND: Leber congenital amaurosis (LCA) and early-onset retinal dystrophy (EORD), are primary causes of inherited childhood blindness. Both are autosomal recessive diseases, with mutations in more than 25 genes explaining approximately ~70% of cases. However, the genetic cause for many cases remains unclear. Sequencing studies from genetically isolated populations with increased prevalence of a disorder has proven useful for rare variant studies, making Costa Rica an ideal place to study LCA/EORD genetics. MATERIALS AND METHODS: Twenty-eight affected children (25 LCA, three EORD) and their immediate family members, totaling 52 individuals (30 affected) from 22 families, were sequenced. Whole exome sequencing was performed on all affected individuals. Available parents were analyzed either by whole exome sequencing (WES) or Sanger sequencing to determine transmission. RESULTS: All affected individuals demonstrated compound heterozygous or homozygous mutations in known Inherited Retinal Disease (IRD) associated genes. Twelve variants were identified in at least one individual in three genes, RDH12, RPE65, and USH2A. Four recurrent RPE65 mutations were observed in 97% of individuals and 95% of families. All patients with LCA and two of the three individuals with EORD had biallelic mutations in RPE65; one child with EORD had a homozygous RDH12 mutation. CONCLUSIONS: These data suggest that the majority of LCA/EORD in Costa Rica is due to four founder mutations in RPE65 which have been maintained in this genetically isolated population. This finding is of great clinical significance due to the availability of gene therapy recently approved in the US and European Union for patients with biallelic RPE65 defects.

New Drugs 2019, part 1.

This article reviews seven drugs recently approved by the FDA, including indications, precautions, adverse reactions, and nursing considerations.

Superior cervical gangliectomy induces non-exudative age-related macular degeneration in mice.

Non-exudative age-related macular degeneration, a prevalent cause of blindness, is a progressive and degenerative disease characterized by alterations in Bruch's membrane, retinal pigment epithelium, and photoreceptors exclusively localized in the macula. Although experimental murine models exist, the vast majority take a long time to develop retinal alterations and, in general, these alterations are ubiquitous, with many resulting from non-eye-specific genetic manipulations; additionally, most do not always reproduce the hallmarks of human age-related macular degeneration. Choroid vessels receive sympathetic innervation from the superior cervical ganglion, which, together with the parasympathetic system, regulates blood flow into the choroid. Choroid blood flow changes have been involved in age-related macular degeneration development and progression. At present, no experimental models take this factor into account. The aim of this work was to analyze the effect of superior cervical gangliectomy (also known as ganglionectomy) on the choroid, Bruch's membrane, retinal pigment epithelium and retina. Adult male C57BL/6J mice underwent unilateral superior cervical gangliectomy and a contralateral sham procedure. Although superior cervical gangliectomy induced ubiquitous choroid and choriocapillaris changes, it induced Bruch's membrane thickening, loss of retinal pigment epithelium melanin content and retinoid isomerohydrolase, the appearance of drusen-like deposits, and retinal pigment epithelium and photoreceptor atrophy, exclusively localized in the temporal side. Moreover, superior cervical gangliectomy provoked a localized increase in retinal pigment epithelium and photoreceptor apoptosis, and a decline in photoreceptor electroretinographic function. Therefore, superior cervical gangliectomy recapitulated the main features of human non-exudative age-related macular degeneration, and could become a new experimental model of dry age-related macular degeneration, and a useful platform for developing new therapies.

Identification of the genetic determinants responsible for retinal degeneration in families of Mexican descent.

PURPOSE: To investigate the clinical characteristics and genetic basis of inherited retinal degeneration (IRD) in six unrelated pedigrees from Mexico. METHODS: A complete ophthalmic evaluation including measurement of visual acuities, Goldman kinetic or Humphrey dynamic perimetry, Amsler test, fundus photography, and color vision testing was performed. Family history and blood samples were collected from available family members. DNA from members of two pedigrees was examined for known mutations using the APEX ARRP genotyping microarray and one pedigree using the APEX LCA genotyping microarray. The remaining three pedigrees were analyzed using a custom-designed targeted capture array covering the exons of 233 known retinal degeneration genes. Sequencing was performed on Illumina HiSeq. Reads were mapped against hg19, and variants were annotated using GATK and filtered by exomeSuite. Segregation and ethnicity-matched control sample analyses were performed by dideoxy sequencing. RESULTS: Six pedigrees with IRD were analyzed. Nine rare or novel, potentially pathogenic variants segregating with the phenotype were detected in IMPDH1, USH2A, RPE65, ABCA4, and FAM161A genes. Among these, six were known mutations while the remaining three changes in USH2A, RPE65, and FAM161A genes have not been previously reported to be associated with IRD. Analysis of 100 ethnicity-matched controls did not detect the presence of these three novel variants indicating, these are rare variants in the Mexican population. CONCLUSIONS: Screening patients diagnosed with IRD from Mexico identified six known mutations and three rare or novel potentially damaging variants in IMPDH1, USH2A, RPE65, ABCA4, and FAM161A genes that segregated with disease.

[Gene therapy for vision restoration in patients with Leber congenital amaurosis (LCA) due to RPE65 gene mutations: beginning the phase IV trial]. / Terapia génica para la restauración de la visión en pacientes con amaurosis congénita de Leber (LCA) por mutación en el gen RPE65: el inicio de la fase IV.

This is a significant time moment in the field of gene therapy in humans. Recently, results from a phase III clinical trial were published, demonstrating the first gene therapy success for a genetic disease. A clinical trial was carried out in patients suffering a hereditary blindness disease named Leber congenital amaurosis, caused by mutations in the RPE65 gene. Participating subjects received a subretinal injection of the normal RPE65 gene and one year after exhibited a significant improvement in visual acuity. It is expected that this gene therapy treatment will be approved by the FDA and commercialized in the USA in 2017.

Avaliaçäo da biopotência dos isômeros 9-cis e 13-cis do ß-caroteno / Evaluation of biopower of isomers 9-cis and 13-cis ofÿß-carotene

O ß-caroteno é o mais importante dentre os carotenóides pró-vitamínicos A, por possuir 100 por cento de atividade vitamínica. Ele é formado por uma mistura de isômeros trans e cis, sendo que as formas cis possuem menor atividade que as formas tran. Dados da literatura, sobre as atividades pró-vitamínicas dos isômeros cis säo antigos e controversos. Assim, nos propusemos a verificar as reais atividades vitamínicas A dos isômeros 9 e 13-cis do ß-caroteno. O estudo foi baseado no modelo de esgotamento das reservas de vitamina a hepáticas em ratos. O ensaio biológico foi dividido em duas etapas: depleçäo e testes. Os grupos formados foram: grupos água e óleo, ambos sem vitamina A, grupos vitamina A, ß-caroteno todo-trans, 9-cis, 13-cis, ß-caroteno todo-trans+9-cis e ß-caroteno todo-trans+13-cis. A quantidade de vitamina A ou de ß-caroteno e seus isômeros fornecidos aos animais foi baseada nas necessidades diárias de vitamina A. Ao final do período de testes todos os animais foram sacrificados e os fígados, sangue e fezes recolhidos para análise em cromatografia líquida de alta eficiência (CLAE). Dos resultados obtidos, pode-se verificar que ocorreu isomerizaçäo do isômero trans em cis e de cis em trans. E, que as biopotências do isômero 9-cis foi de 37,2 por cento e a do 13-cis foi de 45,6 por cento