Macular dystrophies associated with Stargardt-like phenotypes / Distrofias maculares associadas a fenótipos Stargardt-like

ABSTRACT Purpose: Stargardt-like phenotype has been described as associated with pathogenic variants besides the ABCA4 gene. This study aimed to describe four cases with retinal appearance of Stargardt disease phenotypes and unexpected molecular findings. Methods: This report reviewed medical records of four patients with macular dystrophy and clinical features of Stargardt disease. Ophthalmic examination, fundus imaging, and next-generation sequencing were performed to evaluate pathogenic variants related to the phenotypes. Results: Patients presented macular atrophy and pigmentary changes suggesting Stargardt disease. The phenotypes of the two patients were associated with autosomal dominant inheritance pattern genes (RIMS1 and CRX) and in the other two patients were associated with recessive dominant inheritance pattern genes (CRB1 and RDH12) with variants predicted to be pathogenic. Conclusion: Macular dystrophies may have phenotypic similarities to Stargardt-like phenotype associated with other genes besides the classic ones.

RESUMO Objetivo: Fenótipos Stargardt-like já foram asso-ciados a variantes patogênicas no gene ABCA4. O propósito desse estudo é descrever quatro pacientes com achados retinianos semelhantes a doença de Stargardt com resultados moleculares diferentes do esperado. Métodos: Esse relato fez a revisão de prontuários médicos de quatro pacientes com distrofia macular e achados clínicos sugestivos de doença de Stargardt. Foram realizados avaliação oftalmológica, exames de imagens e testes usando next generation sequencing para avaliar variantes patogênicas associadas aos fenótipos dos pacientes. Resultados: Os pacientes apresentavam atrofia macular e alterações pigmentares sugerindo achados clínicos de doença de Stargardt. Dois pacientes foram associados a genes com herança autossômica dominante (RIMS1 e CRX) e dois pacientes foram associados a genes com herança autossômica recessiva (CRB1 e RDH12) com variantes preditoras de serem patogênicas. Conclusão: Distrofias maculares podem ter similaridades fenotípicas com fenótipo de Stargardt-like associados a outros genes além dos classicamente já descritos.

Breaking bad news in ophthalmology: a literature review / Comunicação de más notícias em oftalmologia: uma revisão de literatura

ABSTRACT Medical specialties have recognized that breaking bad news assists clinical practice by mitigating the impact of difficult conversations. This scenario also encourages various studies on breaking bad news in ophthalmology since certain ocular diagnoses can be considered bad news. Thus, the objective is to review the scientific literature on breaking bad news in ophthalmology. The literature databases like MEDLINE/PUBMED, EMBASE, LILACS, SCOPUS, COCHRANE, and SCIELO, were screened for related research publications. Two independent reviewers read all the articles and short-listed the most relevant ones. Seven articles, in the formats of original article, review, editorial, oral communication, and correspondence, were reviewed. Conclusively it reveals that ophthalmologists are concerned with communicating bad news effectively but lack related studies. Nevertheless, there is a growing realization that training in breaking bad news can increase physicians' confidence during communication, thus, benefiting the therapeutic relationship with the patient and his family. Therefore, it would be valuable to include breaking bad news training in the curriculum of residencies.

RESUMO O reconhecimento sobre a comunicação de más notícias como mitigadora de conversas difíceis por outras especialidades médicas, incentiva o estudo desta temática na oftalmologia. Sendo assim, o objetivo deste estudo é revisar a produção de pesquisas científicas sobre a comunicação de más notícias em oftalmologia. Para isso, foi realizada uma revisão de literatura. As bases de dados utilizadas foram MEDLINE/PUBMED, EMBASE, LILACS, SCOPUS, COCHRANE e SCIELO. Dois revisores independentes leram todos os artigos e selecionaram a amostra final. Sete artigos foram escolhidos nos formatos de artigo original, revisão, editorial, comunicação oral e correspondência. Os oftalmologistas estão preocupados em comunicar as más notícias de forma eficaz, mas faltam estudos sobre o tema. No entanto, há uma crescente percepção de que o treinamento de comunicação de más notícias aumenta a confiança dos médicos na comunicação, beneficiando a relação terapêutica. Portanto, seria valioso incluir este treinamento no currículo das residências.

Macular dystrophies associated with Stargardt-like phenotypes.

PURPOSE: Stargardt-like phenotype has been described as associated with pathogenic variants besides the ABCA4 gene. This study aimed to describe four cases with retinal appearance of Stargardt disease phenotypes and unexpected molecular findings. METHODS: This report reviewed medical records of four patients with macular dystrophy and clinical features of Stargardt disease. Ophthalmic examination, fundus imaging, and next-generation sequencing were performed to evaluate pathogenic variants related to the phenotypes. RESULTS: Patients presented macular atrophy and pigmentary changes suggesting Stargardt disease. The phenotypes of the two patients were associated with autosomal dominant inheritance pattern genes (RIMS1 and CRX) and in the other two patients were associated with recessive dominant inheritance pattern genes (CRB1 and RDH12) with variants predicted to be pathogenic. CONCLUSION: Macular dystrophies may have phenotypic similarities to Stargardt-like phenotype associated with other genes besides the classic ones.

DIGEST Scale Predictis More Quality of Life Than PAS: The Residue Influence on Supracricoid Laryngectomy.

Introduction Supracricoid laryngectomy (SCL CHEP) removes ∼ 70% of the larynx, resulting in structural rearrangement and modification of the swallowing mechanism, promoting chronic dysphagia. One of the consequences of this new physiology is the formation of pharyngeal residues that can increase the possibility of aspiration. The formation of residues after SCL CHEP, its functional consequences, and its influence on quality of life (QOL) is still poorly described in the literature. Objective To investigate and compare the association between self-reported QoL and objective assessments of swallowing function in patients undergoing SCL CHEP. Methods A cross-sectional study was performed from 2018 to 2020 in a reference service for head and neck surgery in Brazil. A total of 860 swallowing videofluoroscopy images were evaluated using the Penetration and Aspiration Scale (PAS) and Dynamic Imaging Grade of Swallowing Toxicity (DIGEST). Results In a group of 86 patients, there was a significant relationship between oncological staging and the global ( p < 0.001) and total ( p = 0.002) QoL domains. There was a negative correlation between the DIGEST scale and the emotional domain of the QoL protocol ( p = 0.045). The swallowing function proved to be relevant for QoL. Conclusion The PAS scale did not show any correlation with QoL. The functional performance of swallowing according to the DIGEST scale was coherent with the QOL scores. It is suggested that the residue may be a more relevant aspect for QoL than the aspiration, making DIGEST a promising tool in the assessment of dysphagic patients.

Breaking bad news in ophthalmology: a literature review.

Medical specialties have recognized that breaking bad news assists clinical practice by mitigating the impact of difficult conversations. This scenario also encourages various studies on breaking bad news in ophthalmology since certain ocular diagnoses can be considered bad news. Thus, the objective is to review the scientific literature on breaking bad news in ophthalmology. The literature databases like MEDLINE/PUBMED, EMBASE, LILACS, SCOPUS, COCHRANE, and SCIELO, were screened for related research publications. Two independent reviewers read all the articles and short-listed the most relevant ones. Seven articles, in the formats of original article, review, editorial, oral communication, and correspondence, were reviewed. Conclusively it reveals that ophthalmologists are concerned with communicating bad news effectively but lack related studies. Nevertheless, there is a growing realization that training in breaking bad news can increase physicians' confidence during communication, thus, benefiting the therapeutic relationship with the patient and his family. Therefore, it would be valuable to include breaking bad news training in the curriculum of residencies.

DIGEST Scale Predictis More Quality of Life Than PAS: The Residue Influence on Supracricoid Laryngectomy

Abstract Introduction Supracricoid laryngectomy (SCL CHEP) removes ~ 70% of the larynx, resulting in structural rearrangement and modification of the swallowing mechanism, promoting chronic dysphagia. One of the consequences of this new physiology is the formation of pharyngeal residues that can increase the possibility of aspiration. The formation of residues after SCL CHEP, its functional consequences, and its influence on quality of life (QOL) is still poorly described in the literature. Objective To investigate and compare the association between self-reported QoL and objective assessments of swallowing function in patients undergoing SCL CHEP. Methods A cross-sectional study was performed from 2018 to 2020 in a reference service for head and neck surgery in Brazil. A total of 860 swallowing videofluoroscopy images were evaluated using the Penetration and Aspiration Scale (PAS) and Dynamic Imaging Grade of Swallowing Toxicity (DIGEST). Results In a group of 86 patients, there was a significant relationship between oncological staging and the global (p<0.001) and total (p = 0.002) QoL domains. There was a negative correlation between the DIGEST scale and the emotional domain of the QoL protocol (p = 0.045). The swallowing function proved to be relevant for QoL. Conclusion The PAS scale did not show any correlation with QoL. The functional performance of swallowing according to the DIGEST scale was coherent with the QOL scores. It is suggested that the residue may be a more relevant aspect for QoL than the aspiration, making DIGEST a promising tool in the assessment of dysphagic patients.

Expanding the Phenotypic and Genotypic Spectrum of Bietti Crystalline Dystrophy.

The rare form of retinal dystrophy, Bietti crystalline dystrophy, is associated with variations in CYP4V2, a member of the cytochrome P450 family. This study reports patients affected by typical and atypical Bietti crystalline dystrophy, expanding the spectrum of this disease. This is an observational case series of patients with a clinical and molecular diagnosis of Bietti crystalline dystrophy that underwent multimodal imaging. Four unrelated patients are described with two known variants, c.802-8_810del17insGC and c.518T > G (p.Leu173Trp), and one novel missense variant, c.1169G > T (p.Arg390Leu). The patient with the novel homozygous variant had the most severe phenotype resulting in macular hole formation and retinal detachment in both eyes. To the best of our knowledge, there is no association of these features with Bietti crystalline dystrophy. Patient 1 was the youngest patient and had the mildest phenotype with crystals in the retina without chorioretinal atrophy and visual complaints. Patients 2 and 3 presented with fewer crystals and chorioretinal atrophy. These three patients presented a classic phenotype. The fourth patient presented with an atypical and severe phenotype. This study reveals a new genotype and new phenotype associated with this disorder.

A Proposal for Classification of Retinal Degeneration in Spinocerebellar Ataxia Type 7.

The aim of this study is to propose a classification system for the spinocerebellar ataxia type 7 retinal degeneration (SCA7-RD). Twenty patients with molecularly confirmed SCA7 underwent slit lamp examination, fundus photography, and optical coherence tomography (Spectralis®). Scale for the Assessment and Rating of Ataxia (SARA) and International Cooperative Ataxia Rating Scale (ICARS) were applied, and age, sex, age at symptom onset, and number of CAG expansions were recorded. After analyzing the ophthalmological findings in each participant, a panel of retinal disease experts created a qualitative classification system for SCA7-RD comprising four stages. We assessed the correlations of retinal degeneration severity with SARA and ICARS scores, number of CAG repeats in ATXN7 allele, and age at symptom onset. We graded retinal degeneration as stage 1 in nine participants, as stage 2 in five, and as stage 3 in six. No differences in age and visual symptoms duration were found between groups. SARA and ICARS scores correlated with the severity of SCA7-RD on the classification system (p = 0.024 and p = 0.014, respectively). After adjusting for disease duration, retinal disease stage association with SARA and ICARS scores remained significant (ANCOVA, p < 0.05). The classification system for SCA7-RD was able to characterize different disease stages representing the landmarks in the cone-rod dystrophy natural history. Neurodegeneration appears to occur in parallel in the cerebellum and in the visual pathway. We conclude that retinal degeneration in SCA7 is a potential biomarker of the neurological phenotype severity.

TUBGCP4 - associated microcephaly and chorioretinopathy.

Background Microcephaly and chorioretinopathy (MCCRP) is a rare neuro-ophthalmologic disorder that causes microcephaly and chorioretinopathy. In a recessive inheritance pattern, there are three types: MCCRP1; MCCRP2 and MCCRP3. MCCRP3 results from pathogenic variants in the tubulin-gamma complex-associated protein 4 (TUBGCP4) gene.Materials and Methods This is a case report of a patient with a molecular diagnosis defined by mutations in the TUBGCP4 gene. Segregation analyses were carried out.Results The molecular investigation found two heterozygous variants c.1380 G > A (p.Trp460*) a novel nonsense variant, and c.1746 G > T (p Leu582=) a synonymous variant in TUBGCP4. The clinical phenotype was characterized by microcephaly, microphthalmia, chorioretinopathy, a punched-out retinal appearance, dysmorphic facial features, decreased visual acuity, and learning difficulties. The clinical features were similar to those described previously in children with MCCRP3. The proband also had additional features including centripetal obesity, stretch marks, acanthosis nigricans, scoliosis, and hypercholesterolemia. These other features could be part of a ciliopathy syndrome.Conclusions MCCRP2 caused by pathogenic variants in PLK4 is well established as a ciliopathy disease. The role of TUBGCP4 is not well established in the cilium physiology. MCCRP3 may be part of the ciliopathy spectrum.

Synonymous Variant in the CHM Gene Causes Aberrant Splicing in Choroideremia.

Purpose: Choroideremia is an inherited retinal degeneration caused by 280 different pathogenic variants in the CHM gene. Only one silent/synonymous variant (c.1359C>T; p.(Ser453=)) has been reported and was classified as inconclusive based on in silico analysis. This study elucidates the pathogenicity of this variant also found in a Brazilian patient. Methods: Ophthalmological examinations such as color fundus photography, spectral-domain optical coherence tomography, fundus autofluorescence, and macular integrity assessment microperimetry were performed. The subjects' total RNA was extracted from peripheral blood cells. cDNA was synthesized and the amplification between exon 10 and 14 of the CHM mRNA was performed. The amplification products were sequenced by Sanger sequencing and the results were aligned to the reference sequence. Results: The synonymous variant c.1359C>T p.(Ser453=) in the CHM gene is associated with an error in mRNA processing, leading preferentially to production of an aberrant transcript without exon 11 (p.(Gln451Phefs*3)). This anomalous mRNA production is related to typical choroideremia phenotype. Conclusions: These molecular findings reinforce the need for more detailed investigation of silent variants in patients with well-defined phenotype of retinal dystrophies. Molecular and clinical findings provided evidence that c.1359C>T (p.(Gln451Phefs*3)) in CHM should be considered a disease-causing variant.

Retinitis Pigmentosa Due to Rp1 Biallelic Variants.

In the present study, we screened 529 Brazilian individuals affected by inherited retinal disorders. A total of seven unrelated and nonsyndromic patients with RP1 biallelic variants (OMIM # 180100) were diagnosed in our centre and included in the study. They had classic retinitis pigmentosa with diagnosis at the first decade of life. The visual acuities were severely affected at a young age. The fundus aspects were similar among all patients. An atrophic ring was present around the fovea in several cases. All patients had molecular diagnosis, with six different RP1 variants. This study reports two new pathogenic variants - two frameshift duplications (c.1234dupA p.Met412Asnfs*7 and c.1265dupC p.Ala423Cysfs*2) and reinforces other four known pathogenic variants - two frameshift deletions (c.469delG p.Val157Trpfs*16 and c.3843delT p.Pro1282Leufs*12) and two stop gain mutations (c.1186 C > T p.Arg396* and c.1625C > G p.Ser542*). These findings broaden the spectrum of RP1 variants. This study also reviewed the fundus characteristics that clinically could raise the hypothesis of a retinitis pigmentosa due to RP1 gene. It is worthwhile to try to identify the disease-causing variants in each patient since it can provide prognostic information and be useful in genetic consultation and diagnosis in the future.

Relacionamentos familiares de pessoas com transtornos mentais: processos de exclusão e inclusão social / Family relationships of people with mental health problems: processes of social exclusion and inclusion / Relaciones familiares de personas con trastornos mentales: procesos de exclusión e inclusión social

Objetivos: identificar e analisar os processos de exclusão e inclusão social que acontecem na família da pessoa com transtorno mental. Método: utilizou-se a abordagem qualitativa como metodologia de pesquisa. Os sujeitos desta investigação foram 17 usuários de um Centro de Atenção Psicossocial, da cidade de São Paulo, e 12 pessoas de sua rede social. Para a coleta de dados foram realizadas entrevistas semiestruturadas e, para apuração dos dados, foi utilizada a análise do discurso. Resultados: identificou-se que a exclusão social dos usuários na família pode ocorrer pela ruptura e distanciamento ou de uma maneira mais sutil. Porém, na medida em que os usuários são valorizados e encontraram um papel na família, se estabelecem relações de troca e de ajuda mútua. Conclusão: os relacionamentos se constroem em um processo dialético, passando por conflitos e situações de reciprocidade

Objectives: to identify and to analyze the processes of social exclusion and inclusion that happen in the family of the person with mental disorder. Method: qualitative approach was used as a research methodology. Subjects of this investigation were 17 users of a Psychosocial Care Center, in the city of São Paulo, Brazil, in addition to 12 people from their social networks. For data collection, semi-structured interviews were realizes and, for data analysis, it was the discourse analysis technique. Results: Social exclusion of users of a Psychosocial Care Center in the family can occur due to social disruption and distance, or in a more subtle way. However, to the extent that users are valued and find a role in the family, relationships of exchange and mutual help are established. Conclusion: relationships are developed in a dialectical process, going through conflicts and situations of reciprocity, with the family being the main social inclusion network of these people.

Objetivos: identificar y analizar los procesos de exclusión e inclusión social que ocurren en la familia de la persona con trastorno mental. Método:se utilizó el enfoque cualitativo como metodología de investigación. Las personas de esta investigación fueron 17 usuarios de un Centro de Atención Psicosocial, en la ciudad de São Paulo, Brasil, además de 12 personas de sus redes sociales. Para la recopilación de datos, se realizaron entrevistas semiestructuradas y, para el análisis de datos, fue la técnica de análisis del discurso. Resultados: la exclusión social de los usuarios de un Centro de Atención Psicosocial en la familia puede ocurrir debido a la interrupción social y la distancia, o de una manera más sutil. Sin embargo, en la medida en que los usuarios sean valorados y encuentren un papel en la familia, se establecen relaciones de intercambio y ayuda mutua. Conclusión: las relaciones se desarrollan en un proceso dialéctico, pasando por conflictos y situaciones de reciprocidad, siendo la familia la principal red de inclusión social de estas personas.

Retinal dystrophies and variants in PRPH2 / Distrofias retinianas e variantes em PRPH2

ABSTRACT - This report presents three patients diagnosed with macular dystrophies with variants in PRPH2. Peripherin-2, the protein of this gene, is important in the morphogenesis and stabilization of the photoreceptor outer segment. Peripherin-2 deficiencies cause cellular apoptosis. Moreover, pathogenic variants in PRPH2 are associated with various diseases, such as pattern, butterfly-shaped pattern, central areolar, adult-onset vitelliform macular, and cone-rod dystrophies as well as retinitis pigmentosa, retinitis punctata albescens, Leber congenital amaurosis, fundus flavimaculatus, and Stargardt disease.

RESUMO - Este relato apresenta três pacientes com diagnóstico de distrofias maculares com mutações no PRPH2. Periferina 2, a proteína deste gene, é importante na morfogênese e estabilização do segmento externo dos fotorreceptores. Deficiências de periferina 2 causam apoptose celular. Além disso, variantes patogênicas no PRPH2 estão relacionadas a diferentes doenças, como distrofia padrão, distrofia padrão em asa de borboleta, distrofia central areolar, distrofia viteliforme do adulto, retinose pigmentar, distrofia de cones e bastonetes, retinite punctata albscens, amaurose congênita de Leber, fundus flavimaculatus e doença de Stargardt.

Retinal dystrophies and variants in PRPH2.

This report presents three patients diagnosed with macular dystrophies with variants in PRPH2. Peripherin-2, the protein of this gene, is important in the morphogenesis and stabilization of the photoreceptor outer segment. Peripherin-2 deficiencies cause cellular apoptosis. Moreover, pathogenic variants in PRPH2 are associated with various diseases, such as pattern, butterfly-shaped pattern, central areolar, adult-onset vitelliform macular, and cone-rod dystrophies as well as retinitis pigmentosa, retinitis punctata albescens, Leber congenital amaurosis, fundus flavimaculatus, and Stargardt disease.

Relative frequency of inherited retinal dystrophies in Brazil.

Among the Brazilian population, the frequency rates of inherited retinal dystrophies and their causative genes are underreported. To increase the knowledge about these dystrophies in our population, we retrospectively studied the medical records of 1,246 Brazilian patients with hereditary retinopathies during 20 years of specialized outpatient clinic care. Of these patients, 559 had undergone at least one genetic test. In this cohort, the most prevalent dystrophies were non-syndromic retinitis pigmentosa (35%), Stargardt disease (21%), Leber congenital amaurosis (9%), and syndromic inherited retinal dystrophies (12%). Most patients had never undergone genetic testing (55%), and among the individuals with molecular test results, 28.4% had negative or inconclusive results compared to 71.6% with a conclusive molecular diagnosis. ABCA4 was the most frequent disease-causing gene, accounting for 20% of the positive cases. Pathogenic variants also occurred frequently in the CEP290, USH2A, CRB1, RPGR, and CHM genes. The relative frequency rates of different inherited retinal dystrophies in Brazil are similar to those found globally. Although mutations in more than 250 genes lead to hereditary retinopathies, only 66 genes were responsible for 70% of the cases, which indicated that smaller and cheaper gene panels can be just as effective and provide more affordable solutions for implementation by the Brazilian public health system.

Variants in the ABCA4 gene in a Brazilian population with Stargardt disease.

Purpose: The aim of this study was to analyze and report pathogenic variants in the ABCA4 gene in Brazilian patients with a clinical diagnosis of Stargardt disease. Methods: This retrospective study evaluated variants in the ABCA4 gene in Brazilian patients with Stargardt disease. The patients' visual acuity and age of symptom onset were obtained from previous medical records. The patients were classified according to the autofluorescence patterns. Results: Fifty patients aged between 10 and 65 years from 44 families were included in the study. Among these cases, the mean age of symptom onset was 14 years (range, 5-40 years). ABCA4 gene sequencing was conclusive in 40 patients (80%), negative in two patients (4%), and inconclusive in eight patients (16%). Four families carried homozygous pathogenic variants. Segregation analysis results were available for 23 families. One novel variant was found: p.Ala2084Pro. The most frequent pathogenic variant in this group was p.Arg602Trp (12/100 alleles). Based on the phenotypic characteristics assessed with fundus autofluorescence imaging, 12 patients were classified as having type I phenotype, 16 as having type II, and 18 patients as having type III. The cases classified as type III phenotype included patients who were homozygous for the p.Asn96Asp and p.Arg2030* variants. One patient with a type I phenotype carried the homozygous intronic variant c.3862+1G>A. Conclusions: Next-generation sequencing was effective for the molecular diagnosis of genetic diseases and specifically allowed a conclusive diagnosis in 80% (40/50) of the patients. As the ABCA4 gene does not show a preferential region for pathogenic variants, the diagnosis of Stargardt disease depends on broader analysis of the gene. The most common pathogenic variants in the ABCA4 gene described in the literature were also found in these Brazilian patients. Although some genotype-phenotype correlations were found, more studies regarding the progression of Stargardt disease will help increase our understanding of the pathogenicity of these gene variants.

Novel Complex ABCA4 Alleles in Brazilian Patients With Stargardt Disease: Genotype-Phenotype Correlation.

Purpose: To analyze the presence of complex alleles of the ABCA4 gene in Brazilian patients with Stargardt disease and to assess the correlation with clinical features. Methods: This was an observational cross-sectional study. Patients with a diagnosis of Stargardt disease who presented three pathogenic variants of the ABCA4 gene or who had variants previously described as complex alleles were included. The relatives of these probands were evaluated in the segregation analysis. The patients were evaluated based on age at symptom onset and visual acuity, and the clinical characteristics were classified according to the findings observed on autofluorescence examination. Results: Among the 47 families analyzed, approximately 30% (14/47) presented complex alleles. The segregation analysis in 14 families with cases of Stargardt disease identified three novel complex alleles and one previously described complex allele. The known complex allele p.[Leu541Pro; Ala1038Val] was identified in two families. The novel complex alleles identified were p.[Leu541Pro; Arg1443His] in five families, p.[Ser1642Arg; Val1682_Val1686del] in seven families, and p.[Pro1761Arg; Arg2106Cys] in one family. Furthermore, four new variants (p.Lys22Asn, p.Asp915Asn, p.Glu1447Val, and p.Pro1761Arg) were identified in the second allele of the ABCA4 gene. Conclusions: Segregation analysis is important in order to confirm the molecular diagnosis of patients with Stargardt disease, given the frequency of complex alleles in the ABCA4 gene. The various pathogenic variation combinations observed in this study were associated with different phenotypes.

Gene panel sequencing in Brazilian patients with retinitis pigmentosa.

BACKGROUND: Retinal dystrophies constitute a group of diseases characterized by clinical variability and pronounced genetic heterogeneity. Retinitis pigmentosa is the most common subtype of hereditary retinal dystrophy and is characterized by a progressive loss of peripheral field vision (Tunnel Vision), eventual loss of central vision, and progressive night blindness. The characteristics of the fundus changes include bone-spicule formations, attenuated blood vessels, reduced and/or abnormal electroretinograms, changes in structure imaged by optical coherence tomography, and subjective changes in visual function. The different syndromic and nonsyndromic forms of retinal dystrophies can be attributed to mutations in more than 250 genes. Molecular diagnosis for patients with retinitis pigmentosa has been hampered by extreme genetic and clinical heterogeneity between retinitis pigmentosa and other forms of retinal dystrophies. Next generation sequencing (NGS) technologies are among the most promising techniques to identify pathogenic variations in retinal dystrophies. PURPOSE: The purpose of this study was to discover the molecular diagnosis for Brazilian patients clinically diagnosed with a retinitis pigmentosa pattern of inheritance by using NGS technologies. MATERIALS AND METHODS: Sixteen patients with the clinical diagnosis of retinitis pigmentosa were included in the study. Their DNA was sequenced in a panel with 132 genes related to retinal dystrophies using the Illumina® platform. Sequence analysis and variation calling was performed using Soft Genetics®, NextGene, and Geneticist Assistant software. The criteria for pathogenicity analysis were established according to the results of prediction programs (Polyphen 2, Mutation taster and MetaCore™) and comparison of pathogenic variations found with databases. RESULTS: The identified potentially pathogenic variations were all confirmed by Sanger sequencing. There were 89 variations predicted as pathogenic, but only 10 of them supported the conclusion of the molecular diagnosis. Five of the nine patients were autosomal dominant RP (56%), two (22%) were autosomal recessive RP, and two (22%) were X-linked RP. Nine of the 16 patients (56%) had probably positive or positive results. CONCLUSION: The Next Generation Sequencing used in this study allowed the molecular diagnosis to be confirmed in 56% of the patients and clarified the inheritance pattern of the patient's retinal dystrophies.

The correlation between CRB1 variants and the clinical severity of Brazilian patients with different inherited retinal dystrophy phenotypes.

Inherited retinal dystrophies are characterized by progressive retina degeneration and mutations in at least 250 genes have been associated as disease-causing. CRB1 is one of many genes analyzed in molecular diagnosis for inherited retinal dystrophy. Crumbs homolog-1 protein encoded by CRB1 is important for cell-to-cell contact, polarization of epithelial cells and the morphogenesis of photoreceptors. Pathogenic variants in CRB1 lead to a huge variety of phenotypes ranging from milder forms of inherited retinal dystrophy, such as retinitis pigmentosa to more severe phenotypes such as Leber congenital amaurosis. In this study, seven novel likely-pathogenic variants were identified: four missense variants (p.Leu479Pro, p.Ala921Pro, p.Cys948Arg and p.Asp1031Asn), two frameshift deletions (c.2536_2542del7 and c.3460_3461delTG) and one frameshift indel variant (c.276_294delinsTGAACACTGTAC). Furthermore, two patients with cone-rod dystrophy due to mutations in CRB1 were reported, supporting previous data, in which mutations in CRB1 can also cause cone-rod dystrophy. Finally, our data suggested there was a direct relation between phenotype severity and the mutation effect on protein functionality in 15 Brazilian CRB1 patients.

PROM1 gene variations in Brazilian patients with macular dystrophy.

BACKGROUND: Although the pathogenicity of the prominin-1 (PROM1) gene has already been described as associated with autosomal dominant Stargardt disease, little is known about sequence variations in this gene. PURPOSE: The aim of this study was to evaluate PROM1 gene sequence variations in patients with macular dystrophy. MATERIAL AND METHODS: This retrospective study evaluated variations in the PROM1 gene detected by next-generation sequencing test in patients with macular dystrophy and Stargardt disease. RESULTS: Of 25 medical records of patients with Stargardt disease, three records of patients with PROM1 gene sequence variations were selected for the study. The p.Asp776Val and p.Asp829Asn variants were detected in cases 1 and 2, respectively, and predicted to be pathogenic; they were probably responsible for macular dystrophy in these patients. Case 3 showed a p.Ala643Gly variant in the PROM1 gene and a single variation in the ABCA4 gene, but molecular testing results were inconclusive. CONCLUSIONS: In cases of Stargardt disease, where molecular testing results are inconclusive for pathogenic variations in the ABCA4 gene, variations in the PROM1 gene may occur and be considered responsible for the disease in the molecular analysis. This study described three cases in which variations in PROM1 gene may play a role in the pathogenesis of macular dystrophy or be associated with both autosomal recessive and autosomal dominant inheritance.