RESUMO
BACKGROUND: Periodic fever syndromes (PFS) are an emerging group of autoinflammatory disorders. Clinical overlap exists and multiple genetic analyses may be needed to assist diagnosis. We evaluated the diagnostic value of a 5-gene sequencing panel (5GP) in patients with undiagnosed PFS. METHODS: Simultaneous double strand Sanger sequencing of MEFV, MVK, TNFRSF1A, NLRP3, NLRP12 genes was performed in 42 patients with unexplained PFS. Clinical features were correlated with genetic results. RESULTS: None of 42 patients analyzed displayed a causative genotype. However, single or multiple genetic variants of uncertain significance were detected in 24 subjects. Only in 5 subjects a definite diagnosis was made by taking into account both genetic and clinical data (2 TRAPS syndrome; 2 FMF; 1 FCAS). Statistical analysis showed that patients carrying genetic variants in one or more of the five selected genes displayed a significantly lower response to glucocorticoids compared with subjects who had completely negative genetic results. CONCLUSIONS: The sequencing of multiple genes is of little help in the diagnostics of PFS and can often lead to results of uncertain interpretation, thus the clinically driven sequencing of single genes should remain the recommended approach. However, the presence of single or multiple genetic variants of uncertain significance, even if not allowing any specific diagnosis, correlated with a poorer response to glucocorticoids, possibly indicating a multifactorial subgroup of PFS with differential response to pharmacological treatment.
Assuntos
Síndromes Periódicas Associadas à Criopirina/genética , Febre Familiar do Mediterrâneo/genética , Perfilação da Expressão Gênica , Genótipo , Doenças Hereditárias Autoinflamatórias/genética , Adolescente , Proteínas de Transporte/genética , Criança , Síndromes Periódicas Associadas à Criopirina/diagnóstico , Proteínas do Citoesqueleto/genética , Febre Familiar do Mediterrâneo/diagnóstico , Feminino , Febre , Doenças Hereditárias Autoinflamatórias/diagnóstico , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Modelos Logísticos , Masculino , Mutação/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Estudos Prospectivos , Pirina , Receptores Tipo I de Fatores de Necrose Tumoral/genética , SíndromeRESUMO
Deregulated immune response to gut microflora in genetically predisposed individuals is typical for inflammatory bowel diseases. It is reasonable to assume that genetic association with the disease will be more pronounced in subjects with early onset than adult onset. The nucleotide-binding oligomerization domain containing-2 gene, commonly involved in multifactorial risk of Crohn's disease, and interleukin 10 receptor genes, associated with rare forms of early onset inflammatory bowel diseases, were sequenced in an early onset patient. We identified a novel variant in the NOD2 gene (c.2857A > G p.K953E) and two already described missense variants in the IL10RA gene (S159G and G351R). The new NOD2 missense variant was examined in silico with two online bioinformatics tools to predict the potentially deleterious effects of the mutation. Although cumulative effect of these variations in the early onset of the disease can be only hypothesized, we demonstrated that family information and in silico studies can be used to predict association with the disease.
Assuntos
Colite Ulcerativa/genética , Predisposição Genética para Doença/genética , Mutação de Sentido Incorreto , Proteína Adaptadora de Sinalização NOD2/genética , Idade de Início , Sequência de Aminoácidos , Sequência de Bases , Criança , Colite Ulcerativa/epidemiologia , Doença de Crohn/genética , Análise Mutacional de DNA , Genótipo , Humanos , Subunidade alfa de Receptor de Interleucina-10/genética , Subunidade beta de Receptor de Interleucina-10/genética , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Homologia de Sequência de AminoácidosRESUMO
Mevalonic aciduria (MA), the most severe form of mevalonate kinase deficiency (MKD), is still an orphan drug disease and the pathogenetic mechanisms underlying neuronal dysfunction is still poorly understood. In our study we have investigated the apoptotic mechanism mediated by the exposure of the cultured neuroblastoma cell line, SH-SY5Y, to lovastatin in absence or in presence of the isoprenoid, geranylgeraniol, with the aim of unraveling the pathogenesis of MA. Lovastatin, blocks the mevalonate pathway inhibiting the 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CR), an enzyme of the mevalonate pathway upstream the mevalonate kinase enzyme, reproducing biochemical features similar to those found in MKD. We demonstrate that apoptosis in neuronal lovastatin treated-cells is induced by the mitochondrial pathway, with caspase-9 as the initiator and caspase-3 as the effector caspase. The presence of geranylgeraniol modulates both the caspase-9 and caspase-3 activity in a dose-dependent way, confirming that this isoprenoid enters the mevalonate pathway, is metabolized and finally is able to by-pass the statin biochemical block reconstituting the mevalonate pathway. According to our findings, it should not be the time course adopted that modulates the apoptotic response but rather the isoprenoid itself. Being aware that our results have been obtained using a biochemical model of MKD, and not cells from patients with the disease, we believe our findings increase the knowledge of MA pathogenesis, and may possibly contribute to the development of novel therapeutic strategies.