RESUMO
BACKGROUND: Singleton-Merten syndrome (SGMRT) is a rare immunogenetic disorder that variably features juvenile open-angle glaucoma (JOAG), psoriasiform skin rash, aortic calcifications and skeletal and dental dysplasia. Few families have been described and the genotypic and phenotypic spectrum is poorly defined, with variants in DDX58 (DExD/H-box helicase 58) being one of two identified causes, classified as SGMRT2. METHODS: Families underwent deep systemic phenotyping and exome sequencing. Functional characterisation with in vitro luciferase assays and in vivo interferon signature using bulk and single cell RNA sequencing was performed. RESULTS: We have identified a novel DDX58 variant c.1529A>T p.(Glu510Val) that segregates with disease in two families with SGMRT2. Patients in these families have widely variable phenotypic features and different ethnic background, with some being severely affected by systemic features and others solely with glaucoma. JOAG was present in all individuals affected with the syndrome. Furthermore, detailed evaluation of skin rash in one patient revealed sparse inflammatory infiltrates in a unique distribution. Functional analysis showed that the DDX58 variant is a dominant gain-of-function activator of interferon pathways in the absence of exogenous RNA ligands. Single cell RNA sequencing of patient lesional skin revealed a cellular activation of interferon-stimulated gene expression in keratinocytes and fibroblasts but not in neighbouring healthy skin. CONCLUSIONS: These results expand the genotypic spectrum of DDX58-associated disease, provide the first detailed description of ocular and dermatological phenotypes, expand our understanding of the molecular pathogenesis of this condition and provide a platform for testing response to therapy.
Assuntos
Exantema , Glaucoma de Ângulo Aberto , Odontodisplasia , Proteína DEAD-box 58/genética , Exantema/patologia , Glaucoma de Ângulo Aberto/patologia , Humanos , Interferons/genética , Metacarpo/patologia , Odontodisplasia/genética , Odontodisplasia/patologia , Receptores ImunológicosRESUMO
PURPOSE: To investigate the association between the CFH and ARMS2 gene polymorphisms and age-related macular degeneration (AMD) in a Brazilian cohort. METHODS: We examined 163 individuals with AMD and 154 controls recruited at the Department of Ophthalmology of the Universidade Federal de Minas Gerais, at the Instituto da Visão, and at the Centro Especializado em Olhos, in Brazil, between 2007 and 2012. Genotyping for CFH rs1061170 and ARMS2 rs10490924 single-nucleotide polymorphisms was performed. The odds ratios (OR) for all of the studied genotypes (heterozygous and homozygous) of both genes were calculated compared to homozygous ancestral alleles. RESULTS: Homozygosity for the CFH and ARMS2 at-risk allele was 33.3 and 23.6%, respectively, for AMD individuals and 10.3 and 7.1%, respectively, for controls (p < 0.0001). The OR was 7.2 (95% CI 3.6-14.5; p < 0.001) for the CFH at-risk genotype (CC) and 5.5 (95% CI 2.6-11.8; p < 0.0001) for ARMS2 (TT). Subjects homozygous for both polymorphisms had a much higher risk of developing AMD (n = 14 patients, OR 33.3, 95% CI 12.8-86.4). The proportion of ancestry in each group indicated that AMD patients had a higher European (Caucasian) component than controls. CONCLUSION: CFH and ARMS2 polymorphisms were strongly associated with AMD in this Brazilian cohort.
Assuntos
Degeneração Macular/genética , Polimorfismo de Nucleotídeo Único , Proteínas/genética , Idoso , Brasil/epidemiologia , Estudos de Coortes , Fator H do Complemento/genética , Etnicidade/etnologia , Feminino , Angiofluoresceinografia , Genótipo , Técnicas de Genotipagem , Humanos , Degeneração Macular/diagnóstico , Degeneração Macular/etnologia , Masculino , Razão de Chances , Reação em Cadeia da Polimerase em Tempo Real , Tomografia de Coerência ÓpticaRESUMO
PURPOSE: To investigate the association between VEGF gene polymorphism and age-related macular degeneration (AMD) in a Brazilian cohort. METHODS: We examined 160 affected individuals and 140 sex- and age-matched controls recruited at the Vision Institute and the Retina Department, São Geraldo Hospital, Minas Gerais Federal University, Brazil, between 2007 and 2011. Genotyping for the VEGF rs1413711 single nucleotide polymorphism (SNP) (+674C>T) was performed. The incidence rate ratios and 95% confidence interval (CI) for AMD for this genotype was calculated. The odds ratio (OR) was also assessed by using logistic regression, controlling for CFH and LOC387715 risk genotype. RESULTS: We observed a prevalence of homozygosity (TT genotype) of 18.1% for rs1413711 among AMD cases compared with 5.8% among controls (P < 0.002). The ORs for this polymorphism were 3.6 (95%CI 1.6-8.2) for homozygous subjects and 1.5 (95%CI 1.1-2.1, P < 0.01) if the subject had at least one risk allele. When we studied separately exudative and dry AMD groups, this polymorphism was statistically significant for both groups. Controlling for CFH and LOC387715 risk genotype the OR was 3.0 for VEGF homozygous, and the OR increases if the patient is homozygous for the three genes. CONCLUSION: The present data suggests that VEGF TT genotype is associated with AMD among Brazilian patients.
Assuntos
Degeneração Macular/genética , Polimorfismo de Nucleotídeo Único , Fator A de Crescimento do Endotélio Vascular/genética , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Feminino , Predisposição Genética para Doença , Genótipo , Homozigoto , Humanos , Incidência , Degeneração Macular/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Reação em Cadeia da Polimerase em Tempo RealRESUMO
A case of human intraocular dirofilariasis is reported from northern Brazil. The nematode was morphologically and phylogenetically related to Dirofilaria immitis but distinct from reference sequences, including those of D. immitis infesting dogs in the same area. A zoonotic Dirofilaria species infesting wild mammals in Brazil and its implications are discussed.