RESUMO
PURPOSE: Interneuronopathies are a group of neurodevelopmental disorders characterized by deficient migration and differentiation of gamma-aminobutyric acidergic interneurons resulting in a broad clinical spectrum, including autism spectrum disorders, early-onset epileptic encephalopathy, intellectual disability, and schizophrenic disorders. SP9 is a transcription factor belonging to the Krüppel-like factor and specificity protein family, the members of which harbor highly conserved DNA-binding domains. SP9 plays a central role in interneuron development and tangential migration, but it has not yet been implicated in a human neurodevelopmental disorder. METHODS: Cases with SP9 variants were collected through international data-sharing networks. To address the specific impact of SP9 variants, in silico and in vitro assays were carried out. RESULTS: De novo heterozygous variants in SP9 cause a novel form of interneuronopathy. SP9 missense variants affecting the glutamate 378 amino acid result in severe epileptic encephalopathy because of hypomorphic and neomorphic DNA-binding effects, whereas SP9 loss-of-function variants result in a milder phenotype with epilepsy, developmental delay, and autism spectrum disorder. CONCLUSION: De novo heterozygous SP9 variants are responsible for a neurodevelopmental disease. Interestingly, variants located in conserved DNA-binding domains of KLF/SP family transcription factors may lead to neomorphic DNA-binding functions resulting in a combination of loss- and gain-of-function effects.
Assuntos
Transtorno do Espectro Autista , Epilepsia , Deficiência Intelectual , Interneurônios , Fatores de Transcrição Sp , Fatores de Transcrição , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/patologia , Epilepsia/genética , Epilepsia/patologia , Heterozigoto , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Interneurônios/metabolismo , Interneurônios/patologia , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/patologia , Fenótipo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição Sp/genéticaRESUMO
PURPOSE: In this study, we describe the phenotype and genotype of the largest cohort of patients with Joubert syndrome (JS) carrying pathogenic variants on one of the most frequent causative genes, CC2D2A. METHODS: We selected 53 patients with pathogenic variants on CC2D2A, compiled and analysed their clinical, neuroimaging and genetic information and compared it to previous literature. RESULTS: Developmental delay (motor and language) was nearly constant but patients had normal intellectual efficiency in 74% of cases (20/27 patients) and 68% followed mainstream schooling despite learning difficulties. Epilepsy was found in only 13% of cases. Only three patients had kidney cysts, only three had genuine retinal dystrophy and no subject had liver fibrosis or polydactyly. Brain MRIs showed typical signs of JS with rare additional features. Genotype-phenotype correlation findings demonstrate a homozygous truncating variant p.Arg950* linked to a more severe phenotype. CONCLUSION: This study contradicts previous literature stating an association between CC2D2A-related JS and ventriculomegaly. Our study implies that CC2D2A-related JS is linked to positive neurodevelopmental outcome and low rate of other organ defects except for homozygous pathogenic variant p.Arg950*. This information will help modulate patient follow-up and provide families with accurate genetic counselling.
Assuntos
Anormalidades Múltiplas , Anormalidades do Olho , Doenças Renais Císticas , Humanos , Cerebelo/diagnóstico por imagem , Cerebelo/patologia , Doenças Renais Císticas/diagnóstico , Doenças Renais Císticas/genética , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Anormalidades do Olho/diagnóstico , Anormalidades do Olho/genética , Anormalidades do Olho/patologia , Retina/diagnóstico por imagem , Retina/patologia , Proteínas do CitoesqueletoRESUMO
OBJECTIVE: To describe the clinical features and course of liver involvement in a cohort of patients with Niemann-Pick type C disease (NP-C), a severe lysosomal storage disorder. STUDY DESIGN: Patients with genetically confirmed NP-C (NPC1, n = 31; NPC2, n = 3) and liver involvement before age 6 months were retrospectively included. Clinical, laboratory test, and imaging data were collected until the last follow-up or death; available liver biopsy specimens were studied using anti-CD68 immunostaining. RESULTS: At initial evaluation (median age, 17 days of life), all patients had hepatomegaly, 33 had splenomegaly, and 30 had neonatal cholestasis. Portal hypertension and liver failure developed in 9 and 4 patients, respectively. Liver biopsy studies, performed in 16 patients, revealed significant fibrosis in all 16 and CD68+ storage cells in 15. Serum alpha-fetoprotein concentration measured in 21 patients was elevated in 17. Plasma oxysterol concentrations were increased in the 16 patients tested. Four patients died within 6 months of life, including 3 from liver involvement. In patients who survived beyond age 6 months (median follow-up, 6.1 years), cholestasis regressed in all, and portal hypertension regressed in all but 1; 25 patients developed neurologic involvement, which was fatal in 16 patients. CONCLUSIONS: Liver involvement in NP-C consisted of transient neonatal cholestasis with hepatosplenomegaly, was associated with liver fibrosis, and was responsible for death in 9% of patients. The combination of liver anti-CD68 immunostaining, serum alpha-fetoprotein measurement, and studies of plasma biomarkers should facilitate early identification of NP-C.
Assuntos
Hepatopatias , Doença de Niemann-Pick Tipo C , Humanos , Lactente , Recém-Nascido , alfa-Fetoproteínas/análise , Colestase/etiologia , Hepatomegalia/etiologia , Hipertensão Portal/etiologia , Doença de Niemann-Pick Tipo C/sangue , Doença de Niemann-Pick Tipo C/complicações , Doença de Niemann-Pick Tipo C/diagnóstico , Doença de Niemann-Pick Tipo C/imunologia , Estudos Retrospectivos , Hepatopatias/diagnóstico , Hepatopatias/etiologia , Hepatopatias/imunologia , Hepatopatias/patologia , Fígado/imunologia , Fígado/patologia , Biópsia , Cirrose Hepática/etiologia , Biomarcadores/sangue , Oxisteróis/sangueRESUMO
Loss of function variants in CACNA1A cause a broad spectrum of neurological disorders, including episodic ataxia, congenital or progressive ataxias, epileptic manifestations or developmental delay. Variants located on the AG/GT consensus splice sites are usually considered as responsible of splicing defects, but exonic or intronic variants located outside of the consensus splice site can also lead to abnormal splicing. We investigated the putative consequences on splicing of 11 CACNA1A variants of unknown significance (VUS) identified in patients with episodic ataxia or congenital ataxia. In silico splice predictions were performed and RNA obtained from fibroblasts was analyzed by Sanger sequencing. The presence of abnormal transcripts was confirmed in 10/11 patients, nine of them were considered as deleterious and one remained of unknown significance. Targeted next-generation RNA sequencing was done in a second step to compare the two methods. This method was successful to obtain the full cDNA sequence of CACNA1A. Despite the presence of several isoforms in the fibroblastic cells, it detected most of the abnormally spliced transcripts. In conclusion, RNA sequencing was efficient to confirm the pathogenicity of nine novel CACNA1A variants. Sanger or Next generation methods can be used depending on the facilities and organization of the laboratories.
Assuntos
Canais de Cálcio , Ataxia Cerebelar , Humanos , Canais de Cálcio/genética , Ataxia/genética , Ataxia Cerebelar/genética , Análise de Sequência de RNARESUMO
GM1 gangliosidosis is a rare lysosomal storage disorder associated with ß-galactosidase enzyme deficiency. There are three types of GM1 gangliosidosis based on age of symptom onset, which correlate with disease severity. In 2019, we performed a retrospective multicentric study including all patients diagnosed with GM1 gangliosidosis in France since 1998. We had access to data for 61 of the 88 patients diagnosed between 1998 and 2019. There were 41 patients with type 1 (symptom onset ≤6 months), 11 with type 2a (symptom onset from 7 months to 2 years), 5 with type 2b (symptom onset from 2 to 3 years), and 4 with type 3 (symptom onset >3 years). The estimated incidence in France was 1/210000. In patients with type 1, the first symptoms were hypotonia (26/41, 63%), dyspnea (7/41, 17%), and nystagmus (6/41, 15%), whereas in patients with type 2a, these were psychomotor regression (9/11, 82%) and seizures (3/11, 27%). In types 2b and 3, the initial symptoms were mild, such as speech difficulties, school difficulties, and progressive psychomotor regression. Hypotonia was observed in all patients, except type 3. The mean overall survival was 23 months (95% confidence interval [CI]: 7, 39) for type 1 and 9.1 years (95% CI: 4.5, 13.5) for type 2a. To the best of our knowledge, this is one of the largest historical cohorts reported, which provides important information on the evolution of all types of GM1 gangliosidosis. These data could be used as a historical cohort in studies assessing potential therapies for this rare genetic disease.
Assuntos
Gangliosidose GM1 , Doenças por Armazenamento dos Lisossomos , Humanos , Gangliosidose GM1/epidemiologia , Gangliosidose GM1/genética , Gangliosidose GM1/diagnóstico , beta-Galactosidase , Estudos Retrospectivos , Hipotonia MuscularRESUMO
INTRODUCTION: This study aims to define the phenotypic and molecular spectrum of the two clinical forms of ß-galactosidase (ß-GAL) deficiency, GM1-gangliosidosis and mucopolysaccharidosis IVB (Morquio disease type B, MPSIVB). METHODS: Clinical and genetic data of 52 probands, 47 patients with GM1-gangliosidosis and 5 patients with MPSIVB were analysed. RESULTS: The clinical presentations in patients with GM1-gangliosidosis are consistent with a phenotypic continuum ranging from a severe antenatal form with hydrops fetalis to an adult form with an extrapyramidal syndrome. Molecular studies evidenced 47 variants located throughout the sequence of the GLB1 gene, in all exons except 7, 11 and 12. Eighteen novel variants (15 substitutions and 3 deletions) were identified. Several variants were linked specifically to early-onset GM1-gangliosidosis, late-onset GM1-gangliosidosis or MPSIVB phenotypes. This integrative molecular and clinical stratification suggests a variant-driven patient assignment to a given clinical and severity group. CONCLUSION: This study reports one of the largest series of b-GAL deficiency with an integrative patient stratification combining molecular and clinical features. This work contributes to expand the community knowledge regarding the molecular and clinical landscapes of b-GAL deficiency for a better patient management.
Assuntos
Gangliosidose GM1 , Mucopolissacaridose IV , Feminino , Gangliosídeo G(M1) , Gangliosidose GM1/genética , Humanos , Mucopolissacaridose IV/genética , Mutação , Gravidez , beta-Galactosidase/genéticaRESUMO
Mucopolysaccharidosis type IIIA (MPS IIIA, also known as Sanfilippo syndrome) is a rare genetic lysosomal storage disease characterized by early and progressive neurodegeneration resulting in a rapid decline in cognitive function affecting speech and language, adaptive behavior, and motor skills. We carried out a prospective observational study to assess the natural history of patients with MPS IIIA, using both standardized tests and patient-centric measures to determine the course of disease progression over a 2-year period. A cohort of 23 patients (7 girls, 16 boys; mean age 28-105 months at baseline) with a confirmed diagnosis of MPS IIIA were assessed and followed up at intervals of 3-6 months; cognitive function was measured using Bayley Scales of Infant and Toddler Development 3rd edition (BSID-III) to derive cognitive development quotients (DQ). Daily living, speech/language development and motor skills were measured using the Vineland Adaptive Behavior Scale (VABS-II). Sleep-wake patterns, behavior and quality-of-life questionnaires were also reported at each visit using parent/caregiver reported outcome tools. All patients had early onset severe MPS IIIA, were diagnosed before 74 months of age, and had cognitive scores below normal developmental levels at baseline. Patients less than 40 months of age at baseline were more likely to continue developing new skills over the first 6-12 months of follow-up. There was a high variability in cognitive developmental age (DA) in patients between 40 and 70 months of age; two-thirds of these patients already had profound cognitive decline, with a DA ≤10 months. The highest cognitive DA achieved in the full study cohort was 34 months. Post hoc, patients were divided into two groups based on baseline cognitive DQ (DQ ≥50 or <50). Cognitive DQ decreased linearly over time, with a decrease from baseline of 30.1 and 9.0 points in patients with cognitive DQ ≥50 at baseline and cognitive DQ <50 at baseline, respectively. Over the 2-year study, VABS-II language scores declined progressively. Motor skills, including walking, declined over time, although significantly later than cognitive decline. No clear pattern of sleep disturbance was observed, but night waking was common in younger patients. Pain scores, as measured on the quality-of-life questionnaire, increased over the study period. The findings of this study strengthen the natural history data on cognitive decline in MPS IIIA and importantly provide additional data on endpoints, validated by the patient community as important to treat, that may form the basis of a multidomain endpoint capturing the disease complexity.
Assuntos
Disfunção Cognitiva , Mucopolissacaridose III , Criança , Pré-Escolar , Cognição , Progressão da Doença , Feminino , Humanos , Lactente , Masculino , Mucopolissacaridose III/diagnóstico , Estudos ProspectivosRESUMO
We present the phenotypes of seven previously unreported patients with Marbach-Schaaf neurodevelopmental syndrome, all carrying the same recurrent heterozygous missense variant c.1003C>T (p.Arg335Trp) in PRKAR1B. Clinical features of this cohort include global developmental delay and reduced sensitivity to pain, as well as behavioral anomalies. Only one of the seven patients reported here was formally diagnosed with autism spectrum disorder (ASD), while ASD-like features were described in others, overall indicating a lower prevalence of ASD in Marbach-Schaaf neurodevelopmental syndrome than previously assumed. The clinical spectrum of the current cohort is similar to that reported in the initial publication, delineating a complex developmental disorder with behavioral and neurologic features. PRKAR1B encodes the regulatory subunit R1ß of the protein kinase A complex (PKA), and is expressed in the adult and embryonal central nervous system in humans. PKA is crucial to a plethora of cellular signaling pathways, and its composition of different regulatory and catalytic subunits is cell-type specific. We discuss potential molecular disease mechanisms underlying the patients' phenotypes with respect to the different known functions of PKA in neurons, and the phenotypes of existing R1ß-deficient animal models.
Assuntos
Transtorno do Espectro Autista , Transtornos do Neurodesenvolvimento , Adulto , Animais , Transtorno do Espectro Autista/genética , Estudos de Coortes , Humanos , Transtornos do Neurodesenvolvimento/genética , Fenótipo , SíndromeRESUMO
OBJECTIVE: Asparagine-linked glycosylation 13 (ALG13) deficiencies have been repeatedly described in the literature with the clinical phenotype of a developmental and epileptic encephalopathy (DEE). Most cases were females carrying the recurrent ALG13 de novo variant, p.(Asn107Ser), with normal transferrin electrophoresis. METHODS: We delineate the phenotypic spectrum of 38 individuals, 37 girls and one boy, 16 of them novel and 22 published, with the most common pathogenic ALG13 variant p.(Asn107Ser) and additionally report the phenotype of three individuals carrying other likely pathogenic ALG13 variants. RESULTS: The phenotypic spectrum often comprised pharmacoresistant epilepsy with epileptic spasms, mostly with onset within the first 6 months of life and with spasm persistence in one-half of the cases. Tonic seizures were the most prevalent additional seizure type. Electroencephalography showed hypsarrhythmia and at a later stage of the disease in one-third of all cases paroxysms of fast activity with electrodecrement. ALG13-related DEE was usually associated with severe to profound developmental delay; ambulation was acquired by one-third of the cases, whereas purposeful hand use was sparse or completely absent. Hand stereotypies and dyskinetic movements including dystonia or choreoathetosis were relatively frequent. Verbal communication skills were absent or poor, and eye contact and pursuit were often impaired. SIGNIFICANCE: X-linked ALG13-related DEE usually manifests as West syndrome with severe to profound developmental delay. It is predominantly caused by the recurrent de novo missense variant p.(Asn107Ser). Comprehensive functional studies will be able to prove or disprove an association with congenital disorder of glycosylation.
Assuntos
Deficiências do Desenvolvimento/fisiopatologia , Epilepsia Resistente a Medicamentos/fisiopatologia , N-Acetilglucosaminiltransferases/genética , Espasmos Infantis/fisiopatologia , Hormônio Adrenocorticotrópico/uso terapêutico , Anticonvulsivantes/uso terapêutico , Criança , Pré-Escolar , Deficiências do Desenvolvimento/genética , Dieta Cetogênica , Epilepsia Resistente a Medicamentos/genética , Epilepsia Resistente a Medicamentos/terapia , Discinesias/genética , Discinesias/fisiopatologia , Eletroencefalografia , Síndromes Epilépticas/genética , Síndromes Epilépticas/fisiopatologia , Síndromes Epilépticas/terapia , Feminino , Glucocorticoides/uso terapêutico , Hormônios/uso terapêutico , Humanos , Lactente , Transtornos do Desenvolvimento da Linguagem/genética , Transtornos do Desenvolvimento da Linguagem/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Mutação de Sentido Incorreto , Fenótipo , Comportamento Social , Espasmos Infantis/genéticaRESUMO
Niemann-Pick disease type C (NPC) is a rare, genetic, progressive neurodegenerative disorder with high unmet medical need. We investigated the safety and efficacy of arimoclomol, which amplifies the heat shock response to target NPC protein misfolding and improve lysosomal function, in patients with NPC. In a 12-month, prospective, randomised, double-blind, placebo-controlled, phase 2/3 trial (ClinicalTrials.gov identifier: NCT02612129), patients (2-18 years) were randomised 2:1 to arimoclomol:placebo, stratified by miglustat use. Routine clinical care was maintained. Arimoclomol was administered orally three times daily. The primary endpoint was change in 5-domain NPC Clinical Severity Scale (NPCCSS) score from baseline to 12 months. Fifty patients enrolled; 42 completed. At month 12, the mean progression from baseline in the 5-domain NPCCSS was 0.76 with arimoclomol vs 2.15 with placebo. A statistically significant treatment difference in favour of arimoclomol of -1.40 (95% confidence interval: -2.76, -0.03; P = .046) was observed, corresponding to a 65% reduction in annual disease progression. In the prespecified subgroup of patients receiving miglustat as routine care, arimoclomol resulted in stabilisation of disease severity over 12 months with a treatment difference of -2.06 in favour of arimoclomol (P = .006). Adverse events occurred in 30/34 patients (88.2%) receiving arimoclomol and 12/16 (75.0%) receiving placebo. Fewer patients had serious adverse events with arimoclomol (5/34, 14.7%) vs placebo (5/16, 31.3%). Treatment-related serious adverse events (n = 2) included urticaria and angioedema. Arimoclomol provided a significant and clinically meaningful treatment effect in NPC and was well tolerated.
Assuntos
Hidroxilaminas/uso terapêutico , Doença de Niemann-Pick Tipo C/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Progressão da Doença , Método Duplo-Cego , Feminino , Humanos , Hidroxilaminas/efeitos adversos , Internacionalidade , Masculino , Doença de Niemann-Pick Tipo C/genética , Estudos Prospectivos , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto JovemRESUMO
IFIH1 gain-of-function has been reported as a cause of a type I interferonopathy encompassing a spectrum of autoinflammatory phenotypes including Aicardi-Goutières syndrome and Singleton Merten syndrome. Ascertaining patients through a European and North American collaboration, we set out to describe the molecular, clinical and interferon status of a cohort of individuals with pathogenic heterozygous mutations in IFIH1. We identified 74 individuals from 51 families segregating a total of 27 likely pathogenic mutations in IFIH1. Ten adult individuals, 13.5% of all mutation carriers, were clinically asymptomatic (with seven of these aged over 50 years). All mutations were associated with enhanced type I interferon signaling, including six variants (22%) which were predicted as benign according to multiple in silico pathogenicity programs. The identified mutations cluster close to the ATP binding region of the protein. These data confirm variable expression and nonpenetrance as important characteristics of the IFIH1 genotype, a consistent association with enhanced type I interferon signaling, and a common mutational mechanism involving increased RNA binding affinity or decreased efficiency of ATP hydrolysis and filament disassembly rate.
Assuntos
Mutação com Ganho de Função , Estudos de Associação Genética , Genótipo , Helicase IFIH1 Induzida por Interferon/genética , Fenótipo , Alelos , Doenças Autoimunes do Sistema Nervoso/diagnóstico , Doenças Autoimunes do Sistema Nervoso/genética , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Helicase IFIH1 Induzida por Interferon/química , Masculino , Modelos Moleculares , Malformações do Sistema Nervoso/diagnóstico , Malformações do Sistema Nervoso/genética , Conformação Proteica , Relação Estrutura-AtividadeRESUMO
5-Amino-4-imidazolecarboxamide-ribosiduria (AICA)-ribosiduria is an exceedingly rare autosomal recessive condition resulting from the disruption of the bifunctional purine biosynthesis protein PURH (ATIC), which catalyzes the last two steps of de novo purine synthesis. It is characterized biochemically by the accumulation of AICA-riboside in urine. AICA-ribosiduria had been reported in only one individual, 15 years ago. In this article, we report three novel cases of AICA-ribosiduria from two independent families, with two novel pathogenic variants in ATIC. We also provide a clinical update on the first patient. Based on the phenotypic features shared by these four patients, we define AICA-ribosiduria as the syndromic association of severe-to-profound global neurodevelopmental impairment, severe visual impairment due to chorioretinal atrophy, ante-postnatal growth impairment, and severe scoliosis. Dysmorphic features were observed in all four cases, especially neonatal/infancy coarse facies with upturned nose. Early-onset epilepsy is frequent and can be pharmacoresistant. Less frequently observed features are aortic coarctation, chronic hepatic cytolysis, minor genital malformations, and nephrocalcinosis. Alteration of the transformylase activity of ATIC might result in a more severe impairment than the alteration of the cyclohydrolase activity. Data from literature points toward a cytotoxic mechanism of the accumulated AICA-riboside.
Assuntos
Anormalidades Congênitas/genética , Epilepsia/genética , Hidroximetil e Formil Transferases/deficiência , Deficiência Intelectual/genética , Complexos Multienzimáticos/genética , Nucleotídeo Desaminases/deficiência , Aminoimidazol Carboxamida/metabolismo , Criança , Pré-Escolar , Feminino , Humanos , Hidroximetil e Formil Transferases/genética , Hidroximetil e Formil Transferases/metabolismo , Lactente , Recém-Nascido , Masculino , Complexos Multienzimáticos/metabolismo , Mutação , Nucleotídeo Desaminases/genética , Nucleotídeo Desaminases/metabolismo , Fenótipo , Ribonucleosídeos/metabolismoRESUMO
Miglustat has been indicated for the treatment of Niemann-Pick disease type C (NP-C) since 2009. The aim of this observational study was to assess the effect of miglustat on long-term survival of patients with NP-C. Data for 789 patients from five large national cohorts and from the NPC Registry were collected and combined. Miglustat-treated and untreated patients overall and within sub-groups according to age-at-neurological-onset, that is, early infantile-onset (<2 years), late infantile-onset (2 to <6 years), juvenile-onset (6 to <15 years), and adolescent/adult-onset (≥15 years) were analysed and compared. Survival was analysed from the time of first neurological manifestation (Neurological onset group, comprising 669 patients) and from diagnosis (Diagnosis group, comprising 590 patients) using a Cox proportional hazard model adjusted for various covariates. Overall, 384 (57.4%) patients in the Neurological onset group and 329 (55.8%) in the Diagnosis group were treated with miglustat. Miglustat treatment was associated with a significant reduction in risk of mortality in both groups (entire Neurological onset group, Hazard ratio [HR] = 0.51; entire Diagnosis group, HR = 0.44; both P < .001). The effect was observed consistently in all age-at-neurological-onset sub-groups (HRs = 0.3 to 0.7) and was statistically significant for late infantile-onset patients in both groups (Neurological onset group, HR = 0.36, P < .05; Diagnosis group, HR = 0.32, P < .01), and juvenile-onset patients in the Diagnosis group only (HR = 0.30, P < .05). Despite the limitations of the data that urge cautious interpretation, the findings are consistent with a beneficial effect of miglustat on survival in patients with NP-C.
Assuntos
1-Desoxinojirimicina/análogos & derivados , Doença de Niemann-Pick Tipo C/tratamento farmacológico , Doença de Niemann-Pick Tipo C/mortalidade , 1-Desoxinojirimicina/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Inibidores Enzimáticos , Feminino , Humanos , Lactente , Recém-Nascido , Internacionalidade , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento , Adulto JovemRESUMO
Gillespie syndrome (GS) is a rare variant form of aniridia characterized by non-progressive cerebellar ataxia, intellectual disability, and iris hypoplasia. Unlike the more common dominant and sporadic forms of aniridia, there has been no significant association with PAX6 mutations in individuals with GS and the mode of inheritance of the disease had long been regarded as uncertain. Using a combination of trio-based whole-exome sequencing and Sanger sequencing in five simplex GS-affected families, we found homozygous or compound heterozygous truncating mutations (c.4672C>T [p.Gln1558(∗)], c.2182C>T [p.Arg728(∗)], c.6366+3A>T [p.Gly2102Valfs5(∗)], and c.6664+5G>T [p.Ala2221Valfs23(∗)]) and de novo heterozygous mutations (c.7687_7689del [p.Lys2563del] and c.7659T>G [p.Phe2553Leu]) in the inositol 1,4,5-trisphosphate receptor type 1 gene (ITPR1). ITPR1 encodes one of the three members of the IP3-receptors family that form Ca(2+) release channels localized predominantly in membranes of endoplasmic reticulum Ca(2+) stores. The truncation mutants, which encompass the IP3-binding domain and varying lengths of the modulatory domain, did not form functional channels when produced in a heterologous cell system. Furthermore, ITPR1 p.Lys2563del mutant did not form IP3-induced Ca(2+) channels but exerted a negative effect when co-produced with wild-type ITPR1 channel activity. In total, these results demonstrate biallelic and monoallelic ITPR1 mutations as the underlying genetic defects for Gillespie syndrome, further extending the spectrum of ITPR1-related diseases.
Assuntos
Aniridia/etiologia , Ataxia Cerebelar/etiologia , Genes Dominantes/genética , Genes Recessivos/genética , Receptores de Inositol 1,4,5-Trifosfato/genética , Deficiência Intelectual/etiologia , Mutação/genética , Adolescente , Aniridia/patologia , Ataxia Cerebelar/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/patologia , Masculino , LinhagemRESUMO
PURPOSE: To investigate the genetic basis of congenital ataxias (CAs), a unique group of cerebellar ataxias with a nonprogressive course, in 20 patients from consanguineous families, and to identify new CA genes. METHODS: Singleton -exome sequencing on these 20 well-clinically characterized CA patients. We first checked for rare homozygous pathogenic variants, then, for variants from a list of genes known to be associated with CA or very early-onset ataxia, regardless of their mode of inheritance. Our replication cohort of 180 CA patients was used to validate the new CA genes. RESULTS: We identified a causal gene in 16/20 families: six known CA genes (7 patients); four genes previously implicated in another neurological phenotype (7 patients); two new candidate genes (2 patients). Despite the consanguinity, 4/20 patients harbored a heterozygous de novo pathogenic variant. CONCLUSION: Singleton exome sequencing in 20 consanguineous CA families led to molecular diagnosis in 80% of cases. This study confirms the genetic heterogeneity of CA and identifies two new candidate genes (PIGS and SKOR2). Our work illustrates the diversity of the pathophysiological pathways in CA, and highlights the pathogenic link between some CA and early infantile epileptic encephalopathies related to the same genes (STXBP1, BRAT1, CACNA1A and CACNA2D2).
Assuntos
Ataxia/genética , Ataxia Cerebelar/genética , Espasmos Infantis/genética , Adolescente , Ataxia/fisiopatologia , Criança , Pré-Escolar , Estudos de Coortes , Exoma/genética , Feminino , França , Heterogeneidade Genética , Predisposição Genética para Doença/genética , Genótipo , Humanos , Masculino , Mutação/genética , Fenótipo , Sequenciamento do Exoma/métodos , Adulto JovemRESUMO
Alpha-mannosidosis (AM) is a very rare (prevalence: 1/500000 births) autosomal recessive lysosomal storage disorder. It is characterized by multi-systemic involvement associated with progressive intellectual disability, hearing loss, skeletal anomalies, and coarse facial features. The spectrum is wide, from very severe and lethal to a milder phenotype that usually progresses slowly. AM is caused by a deficiency of lysosomal alpha-mannosidase. A diagnosis can be established by measuring the activity of lysosomal alpha-mannosidase in leucocytes and screening for abnormal urinary excretion of mannose-rich oligosaccharides. Genetic confirmation is obtained with the identification of MAN2B1 mutations. Enzyme replacement therapy (LAMZEDER ) was approved for use in Europe in August 2018. Here, we describe seven individuals from four families, diagnosed at 3-23 years of age, and who were referred to a clinical geneticist for etiologic exploration of syndromic hearing loss, associated with moderate learning disabilities. Exome sequencing had been used to establish the molecular diagnosis in five cases, including a two-sibling pair. In the remaining two patients, the diagnosis was obtained with screening of urinary oligosaccharides excretion and the association of deafness and hypotonia. These observations emphasize that the clinical diagnosis of AM can be challenging, and that it is likely an underdiagnosed rare cause of syndromic hearing loss. Exome sequencing can contribute significantly to the early diagnosis of these nonspecific mild phenotypes, with advantages for treatment and management.
Assuntos
Perda Auditiva/genética , Deficiência Intelectual/genética , alfa-Manosidase/genética , alfa-Manosidose/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Perda Auditiva/sangue , Perda Auditiva/complicações , Perda Auditiva/patologia , Humanos , Deficiência Intelectual/sangue , Deficiência Intelectual/complicações , Deficiência Intelectual/patologia , Lisossomos/enzimologia , Masculino , Fenótipo , Irmãos , Sequenciamento do Exoma , Adulto Jovem , alfa-Manosidase/sangue , alfa-Manosidose/sangue , alfa-Manosidose/complicações , alfa-Manosidose/patologiaRESUMO
Lysine-specific demethylase 6B (KDM6B) demethylates trimethylated lysine-27 on histone H3. The methylation and demethylation of histone proteins affects gene expression during development. Pathogenic alterations in histone lysine methylation and demethylation genes have been associated with multiple neurodevelopmental disorders. We have identified a number of de novo alterations in the KDM6B gene via whole exome sequencing (WES) in a cohort of 12 unrelated patients with developmental delay, intellectual disability, dysmorphic facial features, and other clinical findings. Our findings will allow for further investigation in to the role of the KDM6B gene in human neurodevelopmental disorders.
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Variação Genética , Histona Desmetilases com o Domínio Jumonji/genética , Transtornos do Neurodesenvolvimento/genética , Adolescente , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , MasculinoRESUMO
BACKGROUND: Metabolomics represent a valuable tool to recover biological information using body fluids and may help to characterize pathophysiological mechanisms of the studied disease. This approach has not been widely used to explore inherited metabolic diseases. This study investigates mucopolysaccharidosis type III (MPS III). A thorough and holistic understanding of metabolic remodeling in MPS III may allow the development, improvement and personalization of patient care. METHODS: We applied both targeted and untargeted metabolomics to urine samples obtained from a French cohort of 49 patients, consisting of 13 MPS IIIA, 16 MPS IIIB, 13 MPS IIIC, and 7 MPS IIID, along with 66 controls. The analytical strategy is based on ultra-high-performance liquid chromatography combined with ion mobility and high-resolution mass spectrometry. Twenty-four amino acids have been assessed using tandem mass spectrometry combined with liquid chromatography. Multivariate data modeling has been used for discriminant metabolite selection. Pathway analysis has been performed to retrieve metabolic pathways impairments. RESULTS: Data analysis revealed distinct biochemical profiles. These metabolic patterns, particularly those related to the amino acid metabolisms, allowed the different studied groups to be distinguished. Pathway analysis unveiled major amino acid pathways impairments in MPS III mainly arginine-proline metabolism and urea cycle metabolism. CONCLUSION: This represents one of the first metabolomics-based investigations of MPS III. These results may shed light on MPS III pathophysiology and could help to set more targeted studies to infer the biomarkers of the affected pathways, which is crucial for rare conditions such as MPS III.
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Aminoácidos/urina , Metabolômica/métodos , Mucopolissacaridose III/metabolismo , Mucopolissacaridose III/urina , Urinálise/métodos , Adolescente , Adulto , Idoso , Algoritmos , Biomarcadores/metabolismo , Criança , Pré-Escolar , Cromatografia Líquida , Análise por Conglomerados , Feminino , Regulação da Expressão Gênica , Humanos , Lactente , Masculino , Redes e Vias Metabólicas , Pessoa de Meia-Idade , Análise Multivariada , Curva ROC , Espectrometria de Massas em Tandem , Adulto JovemRESUMO
INTRODUCTION: This phase III, double-blind, randomised, placebo-controlled trial (and extension phase) was designed to assess the efficacy and safety of velmanase alfa (VA) in alpha-mannosidosis (AM) patients. METHODS: Twenty-five patients were randomised to weekly 1 mg/kg VA or placebo for 52 weeks. At study conclusion, placebo patients switched to VA; 23 patients continued receiving VA in compassionate-use/follow-on studies and were evaluated in the extension phase [last observation (LO)]. Co-primary endpoints were changes in serum oligosaccharide (S-oligo) and in the 3-min stair-climb test (3MSCT). RESULTS: Mean relative change in S-oligo in the VA arm was -77.6% [95% confidence interval (CI) -81.6 to -72.8] at week 52 and -62.9% (95% CI -85.8 to -40.0) at LO; mean relative change in the placebo arm was -24.1% (95% CI -40.3 to -3.6) at week 52 and -55.7% (95% CI -76.4 to -34.9) at LO after switch to active treatment. Mean relative change in 3MSCT at week 52 was -1.1% (95% CI -9.0 to 7.6) and - % (95% CI -13.4 to 6.5) for VA and placebo, respectively. At LO, the mean relative change was 3.9% (95% CI -5.5 to 13.2) in the VA arm and 9.0% (95% CI -10.3 to 28.3) in placebo patients after switch to active treatment. Similar improvement pattern was observed in secondary parameters. A post hoc analysis investigated whether some factors at baseline could account for treatment outcome; none of those factors were predictive of the response to VA, besides age. CONCLUSIONS: These findings support the utility of VA for the treatment of AM, with more evident benefit over time and when treatment is started in the paediatric age.
Assuntos
Terapia de Reposição de Enzimas , alfa-Manosidase/uso terapêutico , alfa-Manosidose/terapia , Adolescente , Adulto , Criança , Pré-Escolar , Método Duplo-Cego , Europa (Continente) , Feminino , Humanos , Masculino , Qualidade de Vida , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto Jovem , alfa-Manosidase/efeitos adversos , alfa-Manosidose/enzimologiaRESUMO
INTRODUCTION: Long-term outcome data provide important insights into the clinical utility of enzyme replacement therapies. Such data are presented for velmanase alfa in the treatment of alpha-mannosidosis (AM). METHODS: Patient data (n = 33; 14 adults, 19 paediatric) from the clinical development programme for velmanase alfa were integrated in this prospectively-designed analysis of long-term efficacy and safety. Patients who participated in the phase I/II or phase III trials and were continuing to receive treatment after completion of the trials were invited to participate in a comprehensive evaluation visit to assess long-term outcomes. Primary endpoints were changes in serum oligosaccharide and the 3-minute stair climb test (3MSCT). RESULTS: Mean (SD) treatment exposure was 29.3 (15.2) months. Serum oligosaccharide levels were significantly reduced in the overall population at 12 months (mean change: -72.7%, P < 0.001) and remained statistically significant at last observation (-62.8%, P < 0.001). A mean improvement of +9.3% in 3MSCT was observed at 12 months (P = 0.013), which also remained statistically significant at last observation (+13.8%, P = 0.004), with a more pronounced improvement detected in the paediatric subgroup. No treatment-emergent adverse events were reported leading to permanent treatment discontinuation. CONCLUSIONS: Patients treated with velmanase alfa experienced improvements in biochemical and functional measures that were maintained for up to 4 years. Long term follow-up is important and further supports the use of velmanase alfa as an effective and well-tolerated treatment for AM. Based on the currently available data set, no baseline characteristic can be predictive of treatment outcome. Early treatment during paediatric age showed better outcome in functional endpoints.