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Pathogenic variants in multiple genes on the X chromosome have been implicated in syndromic and non-syndromic intellectual disability disorders. ZFX on Xp22.11 encodes a transcription factor that has been linked to diverse processes including oncogenesis and development, but germline variants have not been characterized in association with disease. Here, we present clinical and molecular characterization of 18 individuals with germline ZFX variants. Exome or genome sequencing revealed 11 variants in 18 subjects (14 males and 4 females) from 16 unrelated families. Four missense variants were identified in 11 subjects, with seven truncation variants in the remaining individuals. Clinical findings included developmental delay/intellectual disability, behavioral abnormalities, hypotonia, and congenital anomalies. Overlapping and recurrent facial features were identified in all subjects, including thickening and medial broadening of eyebrows, variations in the shape of the face, external eye abnormalities, smooth and/or long philtrum, and ear abnormalities. Hyperparathyroidism was found in four families with missense variants, and enrichment of different tumor types was observed. In molecular studies, DNA-binding domain variants elicited differential expression of a small set of target genes relative to wild-type ZFX in cultured cells, suggesting a gain or loss of transcriptional activity. Additionally, a zebrafish model of ZFX loss displayed an altered behavioral phenotype, providing additional evidence for the functional significance of ZFX. Our clinical and experimental data support that variants in ZFX are associated with an X-linked intellectual disability syndrome characterized by a recurrent facial gestalt, neurocognitive and behavioral abnormalities, and an increased risk for congenital anomalies and hyperparathyroidism.
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Hiperparatireoidismo , Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Masculino , Feminino , Animais , Humanos , Deficiência Intelectual/patologia , Peixe-Zebra/genética , Mutação de Sentido Incorreto/genética , Fatores de Transcrição/genética , Fenótipo , Transtornos do Neurodesenvolvimento/genéticaRESUMO
ERI1 is a 3'-to-5' exoribonuclease involved in RNA metabolic pathways including 5.8S rRNA processing and turnover of histone mRNAs. Its biological and medical significance remain unclear. Here, we uncover a phenotypic dichotomy associated with bi-allelic ERI1 variants by reporting eight affected individuals from seven unrelated families. A severe spondyloepimetaphyseal dysplasia (SEMD) was identified in five affected individuals with missense variants but not in those with bi-allelic null variants, who showed mild intellectual disability and digital anomalies. The ERI1 missense variants cause a loss of the exoribonuclease activity, leading to defective trimming of the 5.8S rRNA 3' end and a decreased degradation of replication-dependent histone mRNAs. Affected-individual-derived induced pluripotent stem cells (iPSCs) showed impaired in vitro chondrogenesis with downregulation of genes regulating skeletal patterning. Our study establishes an entity previously unreported in OMIM and provides a model showing a more severe effect of missense alleles than null alleles within recessive genotypes, suggesting a key role of ERI1-mediated RNA metabolism in human skeletal patterning and chondrogenesis.
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Exorribonucleases , Histonas , Humanos , Exorribonucleases/genética , Histonas/genética , Mutação de Sentido Incorreto/genética , RNA Ribossômico 5,8S , RNA , RNA Mensageiro/genéticaRESUMO
Heterogeneous nuclear ribonucleoprotein C (HNRNPC) is an essential, ubiquitously abundant protein involved in mRNA processing. Genetic variants in other members of the HNRNP family have been associated with neurodevelopmental disorders. Here, we describe 13 individuals with global developmental delay, intellectual disability, behavioral abnormalities, and subtle facial dysmorphology with heterozygous HNRNPC germline variants. Five of them bear an identical in-frame deletion of nine amino acids in the extreme C terminus. To study the effect of this recurrent variant as well as HNRNPC haploinsufficiency, we used induced pluripotent stem cells (iPSCs) and fibroblasts obtained from affected individuals. While protein localization and oligomerization were unaffected by the recurrent C-terminal deletion variant, total HNRNPC levels were decreased. Previously, reduced HNRNPC levels have been associated with changes in alternative splicing. Therefore, we performed a meta-analysis on published RNA-seq datasets of three different cell lines to identify a ubiquitous HNRNPC-dependent signature of alternative spliced exons. The identified signature was not only confirmed in fibroblasts obtained from an affected individual but also showed a significant enrichment for genes associated with intellectual disability. Hence, we assessed the effect of decreased and increased levels of HNRNPC on neuronal arborization and neuronal migration and found that either condition affects neuronal function. Taken together, our data indicate that HNRNPC haploinsufficiency affects alternative splicing of multiple intellectual disability-associated genes and that the developing brain is sensitive to aberrant levels of HNRNPC. Hence, our data strongly support the inclusion of HNRNPC to the family of HNRNP-related neurodevelopmental disorders.
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Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Humanos , Deficiência Intelectual/genética , Processamento Alternativo/genética , Ribonucleoproteínas Nucleares Heterogêneas Grupo C/genética , Haploinsuficiência/genética , Transtornos do Neurodesenvolvimento/genética , Ribonucleoproteínas Nucleares Heterogêneas/genéticaRESUMO
BACKGROUND: Among infants with isolated cleft palate, whether primary surgery at 6 months of age is more beneficial than surgery at 12 months of age with respect to speech outcomes, hearing outcomes, dentofacial development, and safety is unknown. METHODS: We randomly assigned infants with nonsyndromic isolated cleft palate, in a 1:1 ratio, to undergo standardized primary surgery at 6 months of age (6-month group) or at 12 months of age (12-month group) for closure of the cleft. Standardized assessments of quality-checked video and audio recordings at 1, 3, and 5 years of age were performed independently by speech and language therapists who were unaware of the trial-group assignments. The primary outcome was velopharyngeal insufficiency at 5 years of age, defined as a velopharyngeal composite summary score of at least 4 (scores range from 0 to 6, with higher scores indicating greater severity). Secondary outcomes included speech development, postoperative complications, hearing sensitivity, dentofacial development, and growth. RESULTS: We randomly assigned 558 infants at 23 centers across Europe and South America to undergo surgery at 6 months of age (281 infants) or at 12 months of age (277 infants). Speech recordings from 235 infants (83.6%) in the 6-month group and 226 (81.6%) in the 12-month group were analyzable. Insufficient velopharyngeal function at 5 years of age was observed in 21 of 235 infants (8.9%) in the 6-month group as compared with 34 of 226 (15.0%) in the 12-month group (risk ratio, 0.59; 95% confidence interval, 0.36 to 0.99; P = 0.04). Postoperative complications were infrequent and similar in the 6-month and 12-month groups. Four serious adverse events were reported (three in the 6-month group and one in the 12-month group) and had resolved at follow-up. CONCLUSIONS: Medically fit infants who underwent primary surgery for isolated cleft palate in adequately resourced settings at 6 months of age were less likely to have velopharyngeal insufficiency at the age of 5 years than those who had surgery at 12 months of age. (Funded by the National Institute of Dental and Craniofacial Research; TOPS ClinicalTrials.gov number, NCT00993551.).
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Fissura Palatina , Insuficiência Velofaríngea , Pré-Escolar , Humanos , Lactente , Pessoal Técnico de Saúde , Fissura Palatina/complicações , Fissura Palatina/cirurgia , Europa (Continente) , Complicações Pós-Operatórias/epidemiologia , Insuficiência Velofaríngea/diagnóstico , Insuficiência Velofaríngea/etiologia , América do Sul , Técnicas de Diagnóstico por CirurgiaRESUMO
BACKGROUND: Persistent Staphylococcus aureus bacteremia is associated with metastatic infection and adverse outcomes, whereas gram-negative bacteremia is normally transient and shorter course therapy is increasingly advocated for affected patients. Whether the prolonged detection of pathogen DNA in blood by culture-independent systems could have prognostic value and guide management decisions is unknown. METHODS: We performed a multicenter, prospective, observational study on 102 patients with bloodstream infection (BSI) to compare time to bloodstream clearance according to T2 magnetic resonance and blood cultures over a 4-day follow-up. We also explored the association between duration of detectable pathogens according to T2 magnetic resonance (magnetic resonance-DNAemia [MR-DNAemia]) and clinical outcomes. RESULTS: Time to bloodstream clearance according to T2 magnetic resonance was significantly longer than blood culture clearance (HR, .54; 95% CI, .39-.75) and did not differ according to the causative pathogen (P = .5). Each additional day of MR-DNAemia increased the odds of persistent infection (defined as metastatic infection or delayed source control) both in the overall population (OR, 1.98; 95% CI, 1.45-2.70) and in S. aureus (OR, 1.92; 95% CI, 1.12-3.29) and gram-negative bacteremia (OR, 2.21; 95% CI, 1.35-3.60). MR-DNAemia duration was also associated with no improvement in Sequential Organ Failure Assessment score at day 7 from infection onset (OR, 1.76; 95% CI, 1.21-2.56). CONCLUSIONS: T2 magnetic resonance may help diagnose BSI in patients on antimicrobials with negative blood cultures as well as to identify patients with metastatic infection, source control failure, or adverse short-term outcome. Future studies may inform its usefulness within the setting of antimicrobial stewardship programs.
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Bacteriemia , Sepse , Humanos , Prognóstico , Staphylococcus aureus , Estudos Prospectivos , Sepse/tratamento farmacológico , Bacteriemia/tratamento farmacológico , Espectroscopia de Ressonância Magnética , Antibacterianos/uso terapêuticoRESUMO
Hepatocellular carcinoma (HCC) is the fastest-growing cause of cancer-related deaths worldwide. Chronic inflammation and fibrosis are the greatest risk factors for the development of HCC. Although the cell of origin for HCC is uncertain, many theories believe this cancer may arise from liver progenitor cells or stem cells. Here, we describe the activation of hepatic stem cells that overexpress the cholecystokinin-B receptor (CCK-BR) after liver injury with either a DDC diet (0.1% 3, 5-diethoxy-carbonyl 1,4-dihydrocollidine) or a NASH-inducing CDE diet (choline-deficient ethionine) in murine models. Pharmacologic blockade of the CCK-BR with a receptor antagonist proglumide or knockout of the CCK-BR in genetically engineered mice during the injury diet reduces the expression of hepatic stem cells and prevents the formation of three-dimensional tumorspheres in culture. RNA sequencing of livers from DDC-fed mice treated with proglumide or DDC-fed CCK-BR knockout mice showed downregulation of differentially expressed genes involved in cell proliferation and oncogenesis and upregulation of tumor suppressor genes compared with controls. Inhibition of the CCK-BR decreases hepatic transaminases, fibrosis, cytokine expression, and alters the hepatic immune cell signature rendering the liver microenvironment less oncogenic. Furthermore, proglumide hastened recovery after liver injury by reversing fibrosis and improving markers of synthetic function. Proglumide is an older drug that is orally bioavailable and being repurposed for liver conditions. These findings support a promising therapeutic intervention applicable to patients to prevent the development of HCC and decrease hepatic fibrosis.NEW & NOTEWORTHY This investigation identified a novel pathway involving the activation of hepatic stem cells and liver oncogenesis. Receptor blockade or genetic disruption of the cholecystokinin-B receptor (CCK-BR) signaling pathway decreased the activation and proliferation of hepatic stem cells after liver injury without eliminating the regenerative capacity of healthy hepatocytes.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Camundongos , Animais , Receptor de Colecistocinina B/genética , Receptor de Colecistocinina B/metabolismo , Carcinoma Hepatocelular/patologia , Proglumida/farmacologia , Neoplasias Hepáticas/metabolismo , Fígado/metabolismo , Fibrose , Células-Tronco/metabolismo , Carcinogênese/metabolismo , Transformação Celular Neoplásica/metabolismo , Colecistocinina/metabolismo , Microambiente TumoralRESUMO
Genome-wide association studies (GWASs) have discovered 20 risk loci in the human genome where germline variants associate with risk of pancreatic ductal adenocarcinoma (PDAC) in populations of European ancestry. Here, we fine-mapped one such locus on chr16q23.1 (rs72802365, p = 2.51 × 10-17, OR = 1.36, 95% CI = 1.31-1.40) and identified colocalization (PP = 0.87) with aberrant exon 5-7 CTRB2 splicing in pancreatic tissues (pGTEx = 1.40 × 10-69, ßGTEx = 1.99; pLTG = 1.02 × 10-30, ßLTG = 1.99). Imputation of a 584 bp structural variant overlapping exon 6 of CTRB2 into the GWAS datasets resulted in a highly significant association with pancreatic cancer risk (p = 2.83 × 10-16, OR = 1.36, 95% CI = 1.31-1.42), indicating that it may underlie this signal. Exon skipping attributable to the deletion (risk) allele introduces a premature stop codon in exon 7 of CTRB2, yielding a truncated chymotrypsinogen B2 protein that lacks chymotrypsin activity, is poorly secreted, and accumulates intracellularly in the endoplasmic reticulum (ER). We propose that intracellular accumulation of a nonfunctional chymotrypsinogen B2 protein leads to ER stress and pancreatic inflammation, which may explain the increased pancreatic cancer risk in carriers of CTRB2 exon 6 deletion alleles.
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Quimotripsina/genética , Neoplasias Pancreáticas/patologia , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Deleção de Sequência , Estudos de Casos e Controles , Quimotripsina/antagonistas & inibidores , Quimotripsina/metabolismo , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Neoplasias Pancreáticas/etiologia , Neoplasias Pancreáticas/metabolismoRESUMO
ANKRD17 is an ankyrin repeat-containing protein thought to play a role in cell cycle progression, whose ortholog in Drosophila functions in the Hippo pathway as a co-factor of Yorkie. Here, we delineate a neurodevelopmental disorder caused by de novo heterozygous ANKRD17 variants. The mutational spectrum of this cohort of 34 individuals from 32 families is highly suggestive of haploinsufficiency as the underlying mechanism of disease, with 21 truncating or essential splice site variants, 9 missense variants, 1 in-frame insertion-deletion, and 1 microdeletion (1.16 Mb). Consequently, our data indicate that loss of ANKRD17 is likely the main cause of phenotypes previously associated with large multi-gene chromosomal aberrations of the 4q13.3 region. Protein modeling suggests that most of the missense variants disrupt the stability of the ankyrin repeats through alteration of core structural residues. The major phenotypic characteristic of our cohort is a variable degree of developmental delay/intellectual disability, particularly affecting speech, while additional features include growth failure, feeding difficulties, non-specific MRI abnormalities, epilepsy and/or abnormal EEG, predisposition to recurrent infections (mostly bacterial), ophthalmological abnormalities, gait/balance disturbance, and joint hypermobility. Moreover, many individuals shared similar dysmorphic facial features. Analysis of single-cell RNA-seq data from the developing human telencephalon indicated ANKRD17 expression at multiple stages of neurogenesis, adding further evidence to the assertion that damaging ANKRD17 variants cause a neurodevelopmental disorder.
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Anormalidades Craniofaciais/etiologia , Heterozigoto , Deficiência Intelectual/etiologia , Transtornos do Desenvolvimento da Linguagem/etiologia , Mutação com Perda de Função , Proteínas de Ligação a RNA/genética , Adolescente , Adulto , Criança , Pré-Escolar , Anormalidades Craniofaciais/patologia , Feminino , Haploinsuficiência , Humanos , Lactente , Deficiência Intelectual/patologia , Transtornos do Desenvolvimento da Linguagem/patologia , Masculino , Linhagem , Fenótipo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Síndrome , Adulto JovemRESUMO
PURPOSE: Valproic acid or valproate is an effective antiepileptic drug; however, embryonic exposure to valproate can result in a teratogenic disorder referred to as fetal valproate syndrome (FVS, OMIM #609442). Currently there are no diagnostic biomarkers for the condition. This study aims to define an episignature biomarker for teratogenic antenatal exposure to valproate. METHODS: DNA extracted from peripheral blood of individuals with teratogenic antenatal exposure to valproate was processed using DNA methylation microarrays. Subsequently, methylation profiling and construction of support vector machine classifiers were performed in R. RESULTS: Genomic DNA methylation analysis was applied, and a distinct DNA methylation profile was identified in the majority of affected individuals. This profile was used to develop a diagnostic episignature classifier. The valproate exposure episignature exhibited high sensitivity and specificity relative to a large reference dataset of unaffected controls and individuals with a wide spectrum of syndromic disorders with episignatures. Gene set enrichment analysis demonstrated an enrichment for terms associated with cell adhesion, including significant overrepresentation of the cadherin superfamily. CONCLUSION: This study provides evidence of a robust peripheral blood-based diagnostic epigenetic biomarker for a prenatal teratogenic disorder.
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OBJECTIVE: This study was undertaken to assess the utility of the Ages and Stages Questionnaire-3rd Edition (ASQ-3) and the Vineland Adaptive Behavior Scales-2nd Edition (VABS-II) as neurodevelopmental screening tools for infants exposed to antiseizure medications in utero, and to examine their suitability for use in large-population signal generation initiatives. METHODS: Participants were women with epilepsy who were recruited from 21 hospitals in England and Northern Ireland during pregnancy between 2014 and 2016. Offspring were assessed at 24 months old using the Bayley Scales of Infant Development-3rd Edition (BSID-III), the VABS-II, and the ASQ-3 (n = 223). The sensitivity and specificity of the ASQ-3 and VABS-II to identify developmental delay at 24 months were examined, using the BSID-III to define cases. RESULTS: The ASQ-3 identified 65 children (29.1%) as at risk of developmental delay at 24 months using standard referral criteria. Using a categorical approach and standard referral criteria to identify delay in the ASQ-3 and BSID-III at 24 months, the ASQ-3 showed excellent sensitivity (90.9%) and moderate specificity (74.1%). Utilizing different cut-points resulted in improved properties and may be preferred in certain contexts. The VABS-II exhibited the strongest psychometric properties when borderline impairment (>1 SD below the mean) was compared to BSID-III referral data (sensitivity = 100.0%, specificity = 96.6%). SIGNIFICANCE: Both the ASQ-3 and VABS-II have good psychometric properties in a sample of children exposed to antiseizure medications when the purpose is the identification of at-risk groups. These findings identify the ASQ-3 as a measure that could be used effectively as part of a tiered surveillance system for teratogenic exposure by identifying a subset of individuals for more detailed investigations. Although the VABS-II has excellent psychometric properties, it is more labor-intensive for both the research team and participants and is available in fewer languages than the ASQ-3.
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Anticonvulsivantes , Deficiências do Desenvolvimento , Epilepsia , Efeitos Tardios da Exposição Pré-Natal , Humanos , Feminino , Anticonvulsivantes/efeitos adversos , Anticonvulsivantes/uso terapêutico , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/diagnóstico , Inquéritos e Questionários , Deficiências do Desenvolvimento/induzido quimicamente , Deficiências do Desenvolvimento/diagnóstico , Pré-Escolar , Epilepsia/tratamento farmacológico , Masculino , Lactente , Pais , Adulto , Complicações na Gravidez/tratamento farmacológico , Sensibilidade e Especificidade , Desenvolvimento Infantil/efeitos dos fármacosRESUMO
Chronic inflammation increases the risk of developing one of several types of cancer. Inflammatory responses are currently thought to be controlled by mechanisms that rely on transcriptional networks that are distinct from those involved in cell differentiation. The orphan nuclear receptor NR5A2 participates in a wide variety of processes, including cholesterol and glucose metabolism in the liver, resolution of endoplasmic reticulum stress, intestinal glucocorticoid production, pancreatic development and acinar differentiation. In genome-wide association studies, single nucleotide polymorphisms in the vicinity of NR5A2 have previously been associated with the risk of pancreatic adenocarcinoma. In mice, Nr5a2 heterozygosity sensitizes the pancreas to damage, impairs regeneration and cooperates with mutant Kras in tumour progression. Here, using a global transcriptomic analysis, we describe an epithelial-cell-autonomous basal pre-inflammatory state in the pancreas of Nr5a2+/- mice that is reminiscent of the early stages of pancreatitis-induced inflammation and is conserved in histologically normal human pancreases with reduced expression of NR5A2 mRNA. In Nr5a2+/-mice, NR5A2 undergoes a marked transcriptional switch, relocating from differentiation-specific to inflammatory genes and thereby promoting gene transcription that is dependent on the AP-1 transcription factor. Pancreatic deletion of Jun rescues the pre-inflammatory phenotype, as well as binding of NR5A2 to inflammatory gene promoters and the defective regenerative response to damage. These findings support the notion that, in the pancreas, the transcriptional networks involved in differentiation-specific functions also suppress inflammatory programmes. Under conditions of genetic or environmental constraint, these networks can be subverted to foster inflammation.
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Diferenciação Celular/genética , Regulação da Expressão Gênica , Inflamação/genética , Pâncreas/metabolismo , Pâncreas/patologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Transcriptoma , Células Acinares/metabolismo , Células Acinares/patologia , Animais , Cromatina/genética , Cromatina/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Redes Reguladoras de Genes/genética , Genes jun/genética , Heterozigoto , Humanos , Camundongos , Especificidade de Órgãos/genética , Pancreatite/genética , Regiões Promotoras Genéticas/genética , Receptores Citoplasmáticos e Nucleares/deficiência , Receptores Citoplasmáticos e Nucleares/genética , Fator de Transcrição AP-1/metabolismoRESUMO
INTRODUCTION/BACKGROUND: Unmet need for seasonal influenza vaccination administration to pediatric patients exists at national and local levels. Vaccination during the perioperative period remains controversial, though opportunity exists to meet vaccination need through perioperative programs. The initial SMART Aim of this quality improvement initiative was to establish and increase seasonal influenza vaccination rate in eligible patients during in person preoperative clinic visits in a pediatric perioperative surgical home (PSH) to 10%. Informed by each prior season's experience, we increased our SMART Aim target for vaccinations in seasons two and three to 15 and 18%, respectively. METHODS: Following the Model for Improvement methodology, the PSH team developed and implemented a perioperative pediatric influenza vaccination program. Across three influenza seasons, key interventions included updates to organizational perioperative vaccination policy, obtaining material influenza vaccination supplies, development of EHR tools, PSH staff education, and communication with patient-families. Rate of eligible patients receiving influenza vaccination at their PSH clinic appointment was tracked over time. Influenza vaccination rates were reported monthly during Season 1, then weekly during seasons two and three. The balancing measure was same day surgery case cancellations related to influenza vaccination given at PSH clinic appointment. Statistical analysis methods utilized include Shewart's control chart and statistical process control (SPC) standards. Special cause variation was determined by eight or more consecutive data points above or below the centerline. RESULTS: The influenza vaccination rates in each of the three influenza seasons exceeded vaccination rate goals of 10, 15, and 18%, respectively. A total of 695 vaccines have been administered since program inception. No same day surgical case cancellations were observed as balancing measure. CONCLUSIONS: Over three consecutive influenza vaccination seasons, we safely established and met vaccination rate goals of 10, 15, and 18% to eligible patients during preoperative clinic visits within a pediatric PSH system. Through iterative PDSA cycles, we continue to identify opportunities for future improvement. This suggests that the perioperative period presents opportunity for seasonal influenza vaccination with potential program expansion to include routine vaccines of childhood.
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Vacinas contra Influenza , Influenza Humana , Criança , Humanos , Influenza Humana/prevenção & controle , Melhoria de Qualidade , Vacinação , Estações do AnoRESUMO
PURPOSE: Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the "ClinVar low-hanging fruit" reanalysis, reasons for the failure of previous analyses, and lessons learned. METHODS: Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. RESULTS: We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). CONCLUSION: The "ClinVar low-hanging fruit" analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock.
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Deficiência Intelectual , Humanos , Sequenciamento do Exoma , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Alelos , GenótipoRESUMO
PURPOSE: Nonerythrocytic αII-spectrin (SPTAN1) variants have been previously associated with intellectual disability and epilepsy. We conducted this study to delineate the phenotypic spectrum of SPTAN1 variants. METHODS: We carried out SPTAN1 gene enrichment analysis in the rare disease component of the 100,000 Genomes Project and screened 100,000 Genomes Project, DECIPHER database, and GeneMatcher to identify individuals with SPTAN1 variants. Functional studies were performed on fibroblasts from 2 patients. RESULTS: Statistically significant enrichment of rare (minor allele frequency < 1 × 10-5) probably damaging SPTAN1 variants was identified in families with hereditary ataxia (HA) or hereditary spastic paraplegia (HSP) (12/1142 cases vs 52/23,847 controls, p = 2.8 × 10-5). We identified 31 individuals carrying SPTAN1 heterozygous variants or deletions. A total of 10 patients presented with pure or complex HSP/HA. The remaining 21 patients had developmental delay and seizures. Irregular αII-spectrin aggregation was noted in fibroblasts derived from 2 patients with p.(Arg19Trp) and p.(Glu2207del) variants. CONCLUSION: We found that SPTAN1 is a genetic cause of neurodevelopmental disorder, which we classified into 3 distinct subgroups. The first comprises developmental epileptic encephalopathy. The second group exhibits milder phenotypes of developmental delay with or without seizures. The final group accounts for patients with pure or complex HSP/HA.
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Epilepsia , Paraplegia Espástica Hereditária , Humanos , Espectrina/genética , Mutação , Epilepsia/genética , Fenótipo , Ataxia , Paraplegia Espástica Hereditária/genética , Convulsões , Paraplegia , LinhagemRESUMO
OBJECTIVE: Despite widespread monotherapy use of lamotrigine or levetiracetam during pregnancy, prospectively collected, blinded child development data are still limited. The NaME (Neurodevelopment of Babies Born to Mothers With Epilepsy) Study prospectively recruited a new cohort of women with epilepsy and their offspring for longitudinal follow-up. METHODS: Pregnant women of <21 weeks gestation (n = 401) were recruited from 21 hospitals in the UK. Data collection occurred during pregnancy (recruitment, trimester 3) and at 12 and 24 months of age. The primary outcome was blinded assessment of infant cognitive, language, and motor development on the Bayley Scales of Infant and Toddler Development (3rd edition) at 24 months of age with supplementary parent reporting on the Vinelands Adaptive Behavior Scales (2nd edition). RESULTS: There were 394 live births, with 277 children (70%) completing the Bayley assessment at 24 months. There was no evidence of an association of prenatal exposure to monotherapy lamotrigine (-.74, SE = 2.9, 95% confidence interval [CI] = -6.5 to 5.0, p = .80) or levetiracetam (-1.57, SE = 3.1, 95% CI = -4.6 to 7.7, p = .62) with poorer infant cognition, following adjustment for other maternal and child factors in comparison to nonexposed children. Similar results were observed for language and motor scores. There was no evidence of an association between increasing doses of either lamotrigine or levetiracetam. Nor was there evidence that higher dose folic acid supplementation (≥5 mg/day) or convulsive seizure exposure was associated with child development scores. Continued infant exposure to antiseizure medications through breast milk was not associated with poorer outcomes, but the number of women breastfeeding beyond 3 months was low. SIGNIFICANCE: These data are reassuring for infant development following in utero exposure to monotherapy lamotrigine or levetiracetam, but child development is dynamic, and future follow-up is required to rule out later emerging effects.
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Epilepsia , Efeitos Tardios da Exposição Pré-Natal , Lactente , Humanos , Feminino , Gravidez , Lamotrigina/uso terapêutico , Levetiracetam/uso terapêutico , Levetiracetam/farmacologia , Mães , Estudos Prospectivos , Epilepsia/tratamento farmacológico , Anticonvulsivantes/efeitos adversos , Desenvolvimento Infantil , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamenteRESUMO
BACKGROUND: Prenatal exposure to certain anti-seizure medications (ASMs) is associated with an increased risk of major congenital malformations (MCM). The majority of women with epilepsy continue taking ASMs throughout pregnancy and, therefore, information on the potential risks associated with ASM treatment is required. OBJECTIVES: To assess the effects of prenatal exposure to ASMs on the prevalence of MCM in the child. SEARCH METHODS: For the latest update of this review, we searched the following databases on 17 February 2022: Cochrane Register of Studies (CRS Web), MEDLINE (Ovid, 1946 to February 16, 2022), SCOPUS (1823 onwards), and ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP). No language restrictions were imposed. SELECTION CRITERIA: We included prospective cohort controlled studies, cohort studies set within pregnancy registries, randomised controlled trials and epidemiological studies using routine health record data. Participants were women with epilepsy taking ASMs; the two control groups were women without epilepsy and untreated women with epilepsy. DATA COLLECTION AND ANALYSIS: Five authors independently selected studies for inclusion. Eight authors completed data extraction and/or risk of bias assessments. The primary outcome was the presence of an MCM. Secondary outcomes included specific types of MCM. Where meta-analysis was not possible, we reviewed included studies narratively. MAIN RESULTS: From 12,296 abstracts, we reviewed 283 full-text publications which identified 49 studies with 128 publications between them. Data from ASM-exposed pregnancies were more numerous for prospective cohort studies (n = 17,963), than data currently available for epidemiological health record studies (n = 7913). The MCM risk for children of women without epilepsy was 2.1% (95% CI 1.5 to 3.0) in cohort studies and 3.3% (95% CI 1.5 to 7.1) in health record studies. The known risk associated with sodium valproate exposure was clear across comparisons with a pooled prevalence of 9.8% (95% CI 8.1 to 11.9) from cohort data and 9.7% (95% CI 7.1 to 13.4) from routine health record studies. This was elevated across almost all comparisons to other monotherapy ASMs, with the absolute risk differences ranging from 5% to 9%. Multiple studies found that the MCM risk is dose-dependent. Children exposed to carbamazepine had an increased MCM prevalence in both cohort studies (4.7%, 95% CI 3.7 to 5.9) and routine health record studies (4.0%, 95% CI 2.9 to 5.4) which was significantly higher than that for the children born to women without epilepsy for both cohort (RR 2.30, 95% CI 1.47 to 3.59) and routine health record studies (RR 1.14, 95% CI 0.80 to 1.64); with similar significant results in comparison to the children of women with untreated epilepsy for both cohort studies (RR 1.44, 95% CI 1.05 to 1.96) and routine health record studies (RR 1.42, 95% CI 1.10 to 1.83). For phenobarbital exposure, the prevalence was 6.3% (95% CI 4.8 to 8.3) and 8.8% (95% CI 0.0 to 9277.0) from cohort and routine health record data, respectively. This increased risk was significant in comparison to the children of women without epilepsy (RR 3.22, 95% CI 1.84 to 5.65) and those born to women with untreated epilepsy (RR 1.64, 95% CI 0.94 to 2.83) in cohort studies; data from routine health record studies was limited. For phenytoin exposure, the prevalence of MCM was elevated for cohort study data (5.4%, 95% CI 3.6 to 8.1) and routine health record data (6.8%, 95% CI 0.1 to 701.2). The prevalence of MCM was higher for phenytoin-exposed children in comparison to children of women without epilepsy (RR 3.81, 95% CI 1.91 to 7.57) and the children of women with untreated epilepsy (RR 2.01. 95% CI 1.29 to 3.12); there were no data from routine health record studies. Pooled data from cohort studies indicated a significantly increased MCM risk for children exposed to lamotrigine in comparison to children born to women without epilepsy (RR 1.99, 95% CI 1.16 to 3.39); with a risk difference (RD) indicating a 1% increased risk of MCM (RD 0.01. 95% CI 0.00 to 0.03). This was not replicated in the comparison to the children of women with untreated epilepsy (RR 1.04, 95% CI 0.66 to 1.63), which contained the largest group of lamotrigine-exposed children (> 2700). Further, a non-significant difference was also found both in comparison to the children of women without epilepsy (RR 1.19, 95% CI 0.86 to 1.64) and children born to women with untreated epilepsy (RR 1.00, 95% CI 0.79 to 1.28) from routine data studies. For levetiracetam exposure, pooled data provided similar risk ratios to women without epilepsy in cohort (RR 2.20, 95% CI 0.98 to 4.93) and routine health record studies (RR 0.67, 95% CI 0.17 to 2.66). This was supported by the pooled results from both cohort (RR 0.71, 95% CI 0.39 to 1.28) and routine health record studies (RR 0.82, 95% CI 0.39 to 1.71) when comparisons were made to the offspring of women with untreated epilepsy. For topiramate, the prevalence of MCM was 3.9% (95% CI 2.3 to 6.5) from cohort study data and 4.1% (0.0 to 27,050.1) from routine health record studies. Risk ratios were significantly higher for children exposed to topiramate in comparison to the children of women without epilepsy in cohort studies (RR 4.07, 95% CI 1.64 to 10.14) but not in a smaller comparison to the children of women with untreated epilepsy (RR 1.37, 95% CI 0.57 to 3.27); few data are currently available from routine health record studies. Exposure in utero to topiramate was also associated with significantly higher RRs in comparison to other ASMs for oro-facial clefts. Data for all other ASMs were extremely limited. Given the observational designs, all studies were at high risk of certain biases, but the biases observed across primary data collection studies and secondary use of routine health records were different and were, in part, complementary. Biases were balanced across the ASMs investigated, and it is unlikely that the differential results observed across the ASMs are solely explained by these biases. AUTHORS' CONCLUSIONS: Exposure in the womb to certain ASMs was associated with an increased risk of certain MCMs which, for many, is dose-dependent.
ANTECEDENTES: La exposición prenatal a determinados fármacos anticonvulsivos (FAC) se asocia con un mayor riesgo de malformaciones congénitas graves (MCG). La mayoría de las mujeres con epilepsia continúan tomando FAC durante todo el embarazo y, por lo tanto, se requiere información sobre los riesgos potenciales asociados con el tratamiento con FAC. OBJETIVOS: Evaluar los efectos de la exposición prenatal a los FAC sobre la prevalencia de MCG en el niño. MÉTODOS DE BÚSQUEDA: Para la última actualización de esta revisión se hicieron búsquedas el 17 de febrero de 2022 en las siguientes bases de datos: Registro Cochrane de Estudios (Cochrane Register of Studies [CRS Web]), MEDLINE (Ovid, 1946 hasta el 16 de febrero de 2022), SCOPUS (1823 en adelante) y ClinicalTrials.gov , Plataforma de registros internacionales de ensayos clínicos (ICTRP). No se impusieron restricciones de idioma. CRITERIOS DE SELECCIÓN: Se incluyeron estudios prospectivos controlados de cohortes, estudios de cohortes establecidos dentro de registros de embarazos, ensayos controlados aleatorizados y estudios epidemiológicos que utilizaron datos rutinarios de los historiales médicos. Las participantes fueron mujeres con epilepsia que tomaban FAC; los dos grupos de control fueron mujeres sin epilepsia y mujeres con epilepsia que no recibían tratamiento. OBTENCIÓN Y ANÁLISIS DE LOS DATOS: Cinco autores seleccionaron de forma independiente los estudios para inclusión. Ocho autores completaron la extracción de los datos y las evaluaciones del riesgo de sesgo. El desenlace principal fue la presencia de una MCG. Los desenlaces secundarios incluyeron tipos específicos de MCG. Cuando no fue posible realizar un metanálisis, los estudios incluidos se examinaron de forma narrativa. RESULTADOS PRINCIPALES: De 12 296 resúmenes, se revisaron 283 publicaciones a texto completo que identificaron 49 estudios con 128 publicaciones entre ellos. Los datos de los embarazos expuestos a FAC fueron más numerosos en el caso de los estudios prospectivos de cohortes (n = 17 963), que los datos actualmente disponibles de estudios de registros sanitarios epidemiológicos (n = 7913). El riesgo de MCG en los hijos de mujeres sin epilepsia fue del 2,1% (IC del 95%: 1,5 a 3,0) en los estudios de cohortes y del 3,3% (IC del 95%: 1,5 a 7,1) en los estudios de registros sanitarios. El riesgo conocido asociado con la exposición al valproato de sodio fue evidente en todas las comparaciones, con una prevalencia agrupada del 9,8% (IC del 95%: 8,1 a 11,9) a partir de los datos de los estudios de cohortes y del 9,7% (IC del 95%: 7,1 a 13,4) a partir de los estudios con datos rutinarios de los historiales médicos. Este fue elevado en casi todas las comparaciones con otros FAC como monoterapia, con diferencias absolutas de riesgo que variaron entre el 5% y el 9%. Múltiples estudios han constatado que el riesgo de MCG depende de la dosis. Los niños expuestos a la carbamazepina tuvieron una mayor prevalencia de MCG tanto en los estudios de cohortes (4,7%; IC del 95%: 3,7 a 5,9) como en los estudios con datos rutinarios de los historiales médicos (4,0%; IC del 95%: 2,9 a 5,4), que fue significativamente superior a la de los niños nacidos de mujeres sin epilepsia tanto en los estudios de cohortes (RR 2,30; IC del 95%: 1,47 a 3,59) como en los estudios de historias clínicas habituales (RR 1,14; IC del 95%: 0,80 a 1,64), con resultados significativos similares en comparación con los hijos de mujeres con epilepsia que no reciben tratamiento tanto en los estudios de cohortes (RR 1,44; IC del 95%: 1,05 a 1,96) como en los estudios con datos rutinarios de los historiales médicos (RR 1,42; IC del 95%: 1,10 a 1,83). Para la exposición al fenobarbital, la prevalencia fue del 6,3% (IC del 95%: 4,8 a 8,3) y del 8,8% IC del 95%: 0,0 a 9277,0) a partir de los datos de estudios de cohortes y los datos de estudios con datos rutinarios de los historiales médicos, respectivamente. Este aumento del riesgo fue significativo en comparación con los hijos de mujeres sin epilepsia (RR 3,22; IC del 95%: 1,84 a 5,65) y los nacidos de mujeres con epilepsia que no reciben tratamiento (RR 1,64; IC del 95%: 0,94 a 2,83) en estudios de cohortes; los datos procedentes de estudios con datos rutinarios de los historiales médicos fueron limitados. En cuanto a la exposición a la fenitoína, la prevalencia de MCG fue elevada en los datos de los estudios de cohortes (5,4%; IC del 95%: 3,6 a 8,1) y en los datos rutinarios de los historiales médicos (6,8%; IC del 95%: 0,1 a 701,2). La prevalencia de MCG fue mayor en los niños expuestos a la fenitoína en comparación con los hijos de mujeres sin epilepsia (RR 3,81; IC del 95%: 1,91 a 7,57) y los hijos de mujeres con epilepsia que no reciben tratamiento (RR 2,01; IC del 95%: 1,29 a 3,12); no hubo datos procedentes de estudios con datos rutinarios de los historiales médicos. Los datos agrupados de los estudios de cohortes indicaron un riesgo significativamente mayor de MCG en los niños expuestos a lamotrigina en comparación con los niños nacidos de mujeres sin epilepsia (RR 1,99; IC del 95%: 1,16 a 3,39); con una diferencia de riesgos (DR) que indica un riesgo 1% mayor de MCG (DR 0,01. IC del 95%: 0,00 a 0,03). Esto no se repitió en la comparación con los hijos de las mujeres con epilepsia que no reciben tratamiento (RR 1,04; IC del 95%: 0,66 a 1,63), que contenía el mayor grupo de niños expuestos a la lamotrigina (> 2700). Además, también se encontró una diferencia no significativa tanto en comparación con los hijos de mujeres sin epilepsia (RR 1,19; IC del 95%: 0,86 a 1,64) como con los hijos de mujeres con epilepsia que no reciben tratamiento (RR 1,00; IC del 95%: 0,79 a 1,28) a partir de los estudios con datos rutinarios. Para la exposición al levetiracetam, los datos agrupados proporcionaron razones de riesgos similares a las de las mujeres sin epilepsia en los estudios de cohortes (RR 2,20; IC del 95%: 0,98 a 4,93) y en los estudios con datos rutinarios de los historiales médicos (RR 0,67; IC del 95%: 0,17 a 2,66). Los resultados agrupados de los estudios de cohortes (RR: 0,71; IC del 95%: 0,39 a 1,28) y de los estudios con datos rutinarios de los historiales médicos (RR: 0,82; IC del 95%: 0,39 a 1,71) respaldan esta afirmación cuando se comparan con los hijos de las mujeres con epilepsia que no reciben tratamiento. En el caso del topiramato, la prevalencia de MCG fue del 3,9% (IC del 95%: 2,3 a 6,5) a partir de los datos de los estudios de cohortes y del 4,1% (0,0 a 27.050,1) a partir de los estudios con datos rutinarios de los historiales médicos. Las razones de riesgos fueron significativamente más altas para los niños expuestos al topiramato en comparación con los hijos de mujeres sin epilepsia en estudios de cohortes (RR 4,07; IC del 95%: 1,64 a 10,14), pero no en una comparación más pequeña con los hijos de mujeres con epilepsia que no reciben tratamiento (RR 1,37; IC del 95%: 0,57 a 3,27); actualmente se dispone de pocos datos a partir de estudios con datos rutinarios de los historiales médicos. La exposición en el útero al topiramato también se asoció con RR significativamente mayores en comparación con otros FAC para las hendiduras orofaciales. Los datos de todos las demás FAC fueron extremadamente limitados. Debido a los diseños observacionales, todos los estudios presentaron un alto riesgo de ciertos sesgos, pero los sesgos observados en los estudios de obtención de datos primarios y el uso secundario de historiales médicos rutinarios fueron diferentes y, en parte, complementarios. Los sesgos estaban equilibrados entre los FAC investigados, y es poco probable que los resultados diferenciales observados entre los FAC se expliquen únicamente por estos sesgos. CONCLUSIONES DE LOS AUTORES: La exposición en el útero a ciertos FAC se asoció con un mayor riesgo de ciertos MCG que, para muchos, depende de la dosis.
Assuntos
Epilepsia , Efeitos Tardios da Exposição Pré-Natal , Gravidez , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Topiramato , Lamotrigina , Fenitoína , Estudos de Coortes , Epilepsia/tratamento farmacológico , Epilepsia/epidemiologiaRESUMO
PURPOSE: The increased adoption of genomic strategies in the clinic makes it imperative for diagnostic laboratories to improve the efficiency of variant interpretation. Clinical exome sequencing (CES) is becoming a valuable diagnostic tool, capable of meeting the diagnostic demand imposed by the vast array of different rare monogenic disorders. We have assessed a clinician-led and phenotype-based approach for virtual gene panel generation for analysis of targeted CES in patients with rare disease in a single institution. METHODS: Retrospective survey of 400 consecutive cases presumed by clinicians to have rare monogenic disorders, referred on singleton basis for targeted CES. We evaluated diagnostic yield and variant workload to characterise the usefulness of a clinician-led approach for generation of virtual gene panels that can incorporate up to three different phenotype-driven gene selection methods. RESULTS: Abnormalities of the nervous system (54.5%), including intellectual disability, head and neck (19%), skeletal system (16%), ear (15%) and eye (15%) were the most common clinical features reported in referrals. Combined phenotype-driven strategies for virtual gene panel generation were used in 57% of cases. On average, 7.3 variants (median=5) per case were retained for clinical interpretation. The overall diagnostic rate of proband-only CES using personalised phenotype-driven virtual gene panels was 24%. CONCLUSIONS: Our results show that personalised virtual gene panels are a cost-effective approach for variant analysis of CES, maintaining diagnostic yield and optimising the use of resources for clinical genomic sequencing in the clinic.
Assuntos
Exoma , Doenças Raras , Exoma/genética , Humanos , Doenças Raras/genética , Estudos Retrospectivos , Sequenciamento do Exoma , Carga de TrabalhoRESUMO
Survival from pancreatic cancer is poor because most cancers are diagnosed in the late stages and there are no therapies to prevent the progression of precancerous pancreatic intraepithelial neoplasms (PanINs). Inhibiting mutant KRASG12D, the primary driver mutation in most human pancreatic cancers, has been challenging. The cholecystokinin-B receptor (CCK-BR) is absent in the normal pancreas but becomes expressed in high grade PanIN lesions and is over-expressed in pancreatic cancer making it a prime target for therapy. We developed a biodegradable nanoparticle polyplex (NP) that binds selectively to the CCK-BR on PanINs and pancreatic cancer to deliver gene therapy. PanIN progression was halted and the pancreas extracellular matrix rendered less carcinogenic in P48-Cre/LSL-KrasG12D/+ mice treated with the CCK-BR targeted NP loaded with siRNA to mutant Kras. The targeted NP also slowed proliferation, decreased metastases and improved survival in mice bearing large orthotopic pancreatic tumors. Safety and toxicity studies were performed in immune competent mice after short or long-term exposure and showed no off-target toxicity by histological or biochemical evaluation. Precision therapy with target-specific NPs provides a novel approach to slow progression of advanced pancreatic cancer and also prevents the development of pancreatic cancer in high-risk subjects without toxicity to other tissues.
Assuntos
Carcinoma in Situ , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Camundongos , Humanos , Animais , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Modelos Animais de Doenças , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/prevenção & controle , Pâncreas/metabolismo , Carcinogênese/genética , Carcinogênese/patologia , Carcinoma in Situ/genética , Carcinoma Ductal Pancreático/patologia , Neoplasias PancreáticasRESUMO
Hepatocellular carcinoma (HCC) is the third leading cause of cancer-associated deaths worldwide. Treatment with immune checkpoint antibodies has shown promise in advanced HCC, but the response is only 15-20%. We discovered a potential target for the treatment of HCC, the cholecystokinin-B receptor (CCK-BR). This receptor is overexpressed in murine and human HCC and not in normal liver tissue. Mice bearing syngeneic RIL-175 HCC tumors were treated with phosphate buffer saline (PBS; control), proglumide (a CCK-receptor antagonist), an antibody to programmed cell death protein 1 (PD-1Ab), or the combination of proglumide and the PD-1Ab. In vitro, RNA was extracted from untreated or proglumide-treated murine Dt81Hepa1-6 HCC cells and analyzed for expression of fibrosis-associated genes. RNA was also extracted from human HepG2 HCC cells or HepG2 cells treated with proglumide and subjected to RNA sequencing. Results showed that proglumide decreased fibrosis in the tumor microenvironment and increased the number of intratumoral CD8+ T cells in RIL-175 tumors. When proglumide was given in combination with the PD-1Ab, there was a further significant increase in intratumoral CD8+ T cells, improved survival, and alterations in genes regulating tumoral fibrosis and epithelial-to-mesenchymal transition. RNAseq results from human HepG2 HCC cells treated with proglumide showed significant changes in differentially expressed genes involved in tumorigenesis, fibrosis, and the tumor microenvironment. The use of the CCK receptor antagonist may improve efficacy of immune checkpoint antibodies and survival in those with advanced HCC.
Assuntos
Carcinoma Hepatocelular , Inibidores de Checkpoint Imunológico , Neoplasias Hepáticas , Proglumida , Receptores da Colecistocinina , Animais , Camundongos , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/metabolismo , Colecistocinina , Fibrose , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/metabolismo , Proglumida/farmacologia , Receptores da Colecistocinina/antagonistas & inibidores , Inibidores de Checkpoint Imunológico/imunologiaRESUMO
The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.