RESUMO
Aicardi-Goutières syndrome is an inflammatory disease occurring due to mutations in any of TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR or IFIH1. We report on 374 patients from 299 families with mutations in these seven genes. Most patients conformed to one of two fairly stereotyped clinical profiles; either exhibiting an in utero disease-onset (74 patients; 22.8% of all patients where data were available), or a post-natal presentation, usually within the first year of life (223 patients; 68.6%), characterized by a sub-acute encephalopathy and a loss of previously acquired skills. Other clinically distinct phenotypes were also observed; particularly, bilateral striatal necrosis (13 patients; 3.6%) and non-syndromic spastic paraparesis (12 patients; 3.4%). We recorded 69 deaths (19.3% of patients with follow-up data). Of 285 patients for whom data were available, 210 (73.7%) were profoundly disabled, with no useful motor, speech and intellectual function. Chilblains, glaucoma, hypothyroidism, cardiomyopathy, intracerebral vasculitis, peripheral neuropathy, bowel inflammation and systemic lupus erythematosus were seen frequently enough to be confirmed as real associations with the Aicardi-Goutieres syndrome phenotype. We observed a robust relationship between mutations in all seven genes with increased type I interferon activity in cerebrospinal fluid and serum, and the increased expression of interferon-stimulated gene transcripts in peripheral blood. We recorded a positive correlation between the level of cerebrospinal fluid interferon activity assayed within one year of disease presentation and the degree of subsequent disability. Interferon-stimulated gene transcripts remained high in most patients, indicating an ongoing disease process. On the basis of substantial morbidity and mortality, our data highlight the urgent need to define coherent treatment strategies for the phenotypes associated with mutations in the Aicardi-Goutières syndrome-related genes. Our findings also make it clear that a window of therapeutic opportunity exists relevant to the majority of affected patients and indicate that the assessment of type I interferon activity might serve as a useful biomarker in future clinical trials.
Assuntos
Adenosina Desaminase/genética , Doenças Autoimunes do Sistema Nervoso/diagnóstico , Doenças Autoimunes do Sistema Nervoso/genética , RNA Helicases DEAD-box/genética , Exodesoxirribonucleases/genética , Proteínas Monoméricas de Ligação ao GTP/genética , Mutação , Malformações do Sistema Nervoso/diagnóstico , Malformações do Sistema Nervoso/genética , Fenótipo , Fosfoproteínas/genética , Ribonuclease H/genética , Estudos de Associação Genética , Genótipo , Humanos , Helicase IFIH1 Induzida por Interferon , Interferons/sangue , Interferons/líquido cefalorraquidiano , Pterinas/líquido cefalorraquidiano , Proteína 1 com Domínio SAM e Domínio HDRESUMO
BACKGROUND: Hereditary spastic paraplegia is a neurodegenerative phenotype characterized by a progressive loss of corticospinal motor tract function. In a majority of affected individuals the pathogenesis remains undetermined. METHODS: We identified a series of patients with a phenotype of nonsyndromic spastic paraplegia in whom no diagnosis had been reached before exome sequencing. We measured the expression of interferon stimulated genes (ISGs) in peripheral blood from these patients. RESULTS: Five patients from four families with previously unexplained spastic paraplegia were identified with mutations in either ADAR1 (one patient), IFIH1 (one patient), or RNASEH2B (three patients from two families). All patients were developmentally normal before the onset of features beginning in the second year of life. All patients remain of normal intellect. Four patients demonstrated normal neuroimaging, while a single patient had features of nonspecific dysmyelination. The patients with ADAR1 and IFIH1-related disease showed a robust interferon signature. The patients with mutations in RNASEH2B demonstrated no (two patients) or a minimal (one patient) upregulation of ISGs compared with controls. CONCLUSIONS: Mutations in ADAR1, IFIH1, and RNASEH2B can cause a phenotype of spastic paraplegia with normal neuroimaging, or in association with nonspecific dysmyelination. Although the presence of an interferon signature can be helpful in interpreting the significance of gene variants in this context, patients with pathogenic mutations in RNASEH2B may demonstrate no upregulation of ISGs in peripheral blood. However, it remains possible that type I interferons act as a neurotoxin in the context of all genotypes.
Assuntos
Adenosina Desaminase/genética , RNA Helicases DEAD-box/genética , Mutação , Proteínas de Ligação a RNA/genética , Ribonuclease H/genética , Paraplegia Espástica Hereditária/genética , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Interferon Tipo I/metabolismo , Helicase IFIH1 Induzida por Interferon , Masculino , Irmãos , Paraplegia Espástica Hereditária/sangueRESUMO
Neurofibromatosis type 2 (NF2) remains a challenging diagnosis in childhood where there may be no neurological involvement. A 12-month-old male in whom NF2 was suspected because of characteristic ophthalmological and cutaneous lesions is reported. Cranial MRI showed no tumours. A pathogenic mutation was identified on NF2 gene analysis. The child developed hypertension due to renal vascular disease. Although renal vascular disease is a recognized complication of neurofibromatosis type 1 (NF1), it has not been reported in NF2.