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1.
Blood ; 141(13): 1574-1583, 2023 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35984902

RESUMO

Although translocation events between chromosome 4 (NSD2 gene) and chromosome 14 (immunoglobulin heavy chain [IgH] locus) (t(4;14)) is considered high risk in newly diagnosed multiple myeloma (NDMM), only ∼30% to 40% of t(4;14) patients are clinically high risk. We generated and compared a large whole genome sequencing (WGS) and transcriptome (RNA sequencing) from 258 t(4;14) (n = 153 discovery, n = 105 replication) and 183 non-t(4;14) NDMM patients with associated clinical data. A landmark survival analysis indicated only ∼25% of t(4;14) patients had an overall survival (OS) <24 months, and a comparative analysis of the patient subgroups identified biomarkers associated with this poor outcome, including translocation breakpoints located in the NSD2 gene and expression of IgH-NSD2 fusion transcripts. Three breakpoints were identified and are designated as: "no-disruption" (upstream of NSD2), "early-disruption" (in the 5' UTR), and "late-disruption" (within the NSD2 gene). Our results show a significant difference in OS based on the location of DNA breakpoints (median OS 28.6 "late-disruption" vs 59.2 "early disruption" vs 75.1 months "no disruption"). These findings have been replicated in an independent replication dataset. Also, univariate and multivariate analysis suggest high-risk markers such as del17p, 1p independently contribute to poor outcome in t(4;14) MM patients.


Assuntos
Mieloma Múltiplo , Humanos , Mieloma Múltiplo/metabolismo , Sequência de Bases , Translocação Genética , Transcriptoma
2.
Blood ; 141(6): 620-633, 2023 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-36223594

RESUMO

Large-scale analyses of genomic data from patients with newly diagnosed multiple myeloma (ndMM) have been undertaken, however, large-scale analysis of relapsed/refractory MM (rrMM) has not been performed. We hypothesize that somatic variants chronicle the therapeutic exposures and clonal structure of myeloma from ndMM to rrMM stages. We generated whole-genome sequencing (WGS) data from 418 tumors (386 patients) derived from 6 rrMM clinical trials and compared them with WGS from 198 unrelated patients with ndMM in a population-based case-control fashion. We identified significantly enriched events at the rrMM stage, including drivers (DUOX2, EZH2, TP53), biallelic inactivation (TP53), noncoding mutations in bona fide drivers (TP53BP1, BLM), copy number aberrations (CNAs; 1qGain, 17pLOH), and double-hit events (Amp1q-ISS3, 1qGain-17p loss-of-heterozygosity). Mutational signature analysis identified a subclonal defective mismatch repair signature enriched in rrMM and highly active in high mutation burden tumors, a likely feature of therapy-associated expanding subclones. Further analysis focused on the association of genomic aberrations enriched at different stages of resistance to immunomodulatory agent (IMiD)-based therapy. This analysis revealed that TP53, DUOX2, 1qGain, and 17p loss-of-heterozygosity increased in prevalence from ndMM to lenalidomide resistant (LENR) to pomalidomide resistant (POMR) stages, whereas enrichment of MAML3 along with immunoglobulin lambda (IGL) and MYC translocations distinguished POM from the LEN subgroup. Genomic drivers associated with rrMM are those that confer clonal selective advantage under therapeutic pressure. Their role in therapy evasion should be further evaluated in longitudinal patient samples, to confirm these associations with the evolution of clinical resistance and to identify molecular subsets of rrMM for the development of targeted therapies.


Assuntos
Mieloma Múltiplo , Humanos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Oxidases Duais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Lenalidomida/uso terapêutico , Fatores Imunológicos/uso terapêutico , Dexametasona/uso terapêutico
3.
Hum Mol Genet ; 31(17): 2934-2950, 2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-35405010

RESUMO

DROSHA encodes a ribonuclease that is a subunit of the Microprocessor complex and is involved in the first step of microRNA (miRNA) biogenesis. To date, DROSHA has not yet been associated with a Mendelian disease. Here, we describe two individuals with profound intellectual disability, epilepsy, white matter atrophy, microcephaly and dysmorphic features, who carry damaging de novo heterozygous variants in DROSHA. DROSHA is constrained for missense variants and moderately intolerant to loss-of-function (o/e = 0.24). The loss of the fruit fly ortholog drosha causes developmental arrest and death in third instar larvae, a severe reduction in brain size and loss of imaginal discs in the larva. Loss of drosha in eye clones causes small and rough eyes in adult flies. One of the identified DROSHA variants (p.Asp1219Gly) behaves as a strong loss-of-function allele in flies, while another variant (p.Arg1342Trp) is less damaging in our assays. In worms, a knock-in that mimics the p.Asp1219Gly variant at a worm equivalent residue causes loss of miRNA expression and heterochronicity, a phenotype characteristic of the loss of miRNA. Together, our data show that the DROSHA variants found in the individuals presented here are damaging based on functional studies in model organisms and likely underlie the severe phenotype involving the nervous system.


Assuntos
Epilepsia , Deficiência Intelectual , MicroRNAs , Microcefalia , Malformações do Sistema Nervoso , Humanos , Deficiência Intelectual/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Microcefalia/genética , Ribonuclease III/genética , Ribonuclease III/metabolismo
4.
Clin Genet ; 105(1): 62-71, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37853563

RESUMO

Genomic medicine has been transformed by next-generation sequencing (NGS), inclusive of exome sequencing (ES) and genome sequencing (GS). Currently, ES is offered widely in clinical settings, with a less prevalent alternative model consisting of hybrid programs that incorporate research ES along with clinical patient workflows. We were among the earliest to implement a hybrid ES clinic, have provided diagnoses to 45% of probands, and have identified several novel candidate genes. Our program is enabled by a cost-effective investment by the health system and is unique in encompassing all the processes that have been variably included in other hybrid/clinical programs. These include careful patient selection, utilization of a phenotype-agnostic bioinformatics pipeline followed by manual curation of variants and phenotype integration by clinicians, close collaborations between the clinicians and the bioinformatician, pursuit of interesting variants, communication of results to patients in categories that are predicated upon the certainty of a diagnosis, and tracking changes in results over time and the underlying mechanisms for such changes. Due to its effectiveness, scalability to GS and its resource efficiency, specific elements of our paradigm can be incorporated into existing clinical settings, or the entire hybrid model can be implemented within health systems that have genomic medicine programs, to provide NGS in a scientifically rigorous, yet pragmatic setting.


Assuntos
Biologia Computacional , Exoma , Humanos , Exoma/genética , Fenótipo , Sequenciamento do Exoma , Sequenciamento de Nucleotídeos em Larga Escala
5.
Hum Mol Genet ; 30(14): 1283-1292, 2021 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-33864376

RESUMO

The Polycomb group (PcG) gene RNF2 (RING2) encodes a catalytic subunit of the Polycomb repressive complex 1 (PRC1), an evolutionarily conserved machinery that post-translationally modifies chromatin to maintain epigenetic transcriptional repressive states of target genes including Hox genes. Here, we describe two individuals, each with rare de novo missense variants in RNF2. Their phenotypes include intrauterine growth retardation, severe intellectual disabilities, behavioral problems, seizures, feeding difficulties and dysmorphic features. Population genomics data suggest that RNF2 is highly constrained for loss-of-function (LoF) and missense variants, and both p.R70H and p.S82R variants have not been reported to date. Structural analyses of the two alleles indicate that these changes likely impact the interaction between RNF2 and BMI1, another PRC1 subunit or its substrate Histone H2A, respectively. Finally, we provide functional data in Drosophila that these two missense variants behave as LoF alleles in vivo. The evidence provide support for deleterious alleles in RNF2 being associated with a new and recognizable genetic disorder. This tentative gene-disease association in addition to the 12 previously identified disorders caused by PcG genes attests to the importance of these chromatin regulators in Mendelian disorders.


Assuntos
Transtornos do Neurodesenvolvimento , Complexo Repressor Polycomb 1 , Genes Homeobox , Histonas/genética , Humanos , Transtornos do Neurodesenvolvimento/genética , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Proteínas do Grupo Polycomb/genética
6.
EMBO J ; 37(23)2018 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-30420557

RESUMO

A set of glutamylases and deglutamylases controls levels of tubulin polyglutamylation, a prominent post-translational modification of neuronal microtubules. Defective tubulin polyglutamylation was first linked to neurodegeneration in the Purkinje cell degeneration (pcd) mouse, which lacks deglutamylase CCP1, displays massive cerebellar atrophy, and accumulates abnormally glutamylated tubulin in degenerating neurons. We found biallelic rare and damaging variants in the gene encoding CCP1 in 13 individuals with infantile-onset neurodegeneration and confirmed the absence of functional CCP1 along with dysregulated tubulin polyglutamylation. The human disease mainly affected the cerebellum, spinal motor neurons, and peripheral nerves. We also demonstrate previously unrecognized peripheral nerve and spinal motor neuron degeneration in pcd mice, which thus recapitulated key features of the human disease. Our findings link human neurodegeneration to tubulin polyglutamylation, entailing this post-translational modification as a potential target for drug development for neurodegenerative disorders.


Assuntos
Carboxipeptidases/deficiência , Cerebelo/enzimologia , Neurônios Motores/enzimologia , Nervos Periféricos/enzimologia , Células de Purkinje/enzimologia , Coluna Vertebral/enzimologia , Degenerações Espinocerebelares/enzimologia , Cerebelo/patologia , Feminino , Proteínas de Ligação ao GTP , Humanos , Masculino , Neurônios Motores/patologia , Peptídeos/genética , Peptídeos/metabolismo , Nervos Periféricos/patologia , Processamento de Proteína Pós-Traducional , Células de Purkinje/patologia , D-Ala-D-Ala Carboxipeptidase Tipo Serina , Coluna Vertebral/patologia , Degenerações Espinocerebelares/genética , Degenerações Espinocerebelares/patologia
7.
Am J Hum Genet ; 104(2): 299-309, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30686509

RESUMO

Different parts of a gene can be of differential importance to development and health. This regional heterogeneity is also apparent in the distribution of disease-associated mutations, which often cluster in particular regions of disease-associated genes. The ability to precisely estimate functionally important sub-regions of genes will be key in correctly deciphering relationships between genetic variation and disease. Previous methods have had some success using standing human variation to characterize this variability in importance by measuring sub-regional intolerance, i.e., the depletion in functional variation from expectation within a given region of a gene. However, the ability to precisely estimate local intolerance was restricted by the fact that only information within a given sub-region is used, leading to instability in local estimates, especially for small regions. We show that borrowing information across regions using a Bayesian hierarchical model stabilizes estimates, leading to lower variability and improved predictive utility. Specifically, our approach more effectively identifies regions enriched for ClinVar pathogenic variants. We also identify significant correlations between sub-region intolerance and the distribution of pathogenic variation in disease-associated genes, with AUCs for classifying de novo missense variants in Online Mendelian Inheritance in Man (OMIM) genes of up to 0.86 using exonic sub-regions and 0.91 using sub-regions defined by protein domains. This result immediately suggests that considering the intolerance of regions in which variants are found may improve diagnostic interpretation. We also illustrate the utility of integrating regional intolerance into gene-level disease association tests with a study of known disease-associated genes for epileptic encephalopathy.


Assuntos
Componentes do Gene/genética , Modelos Genéticos , Mutação/genética , Espasmos Infantis/genética , Espasmos Infantis/patologia , Teorema de Bayes , Éxons/genética , Humanos
8.
Am J Hum Genet ; 104(3): 530-541, 2019 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-30827496

RESUMO

Acetylation of the lysine residues in histones and other DNA-binding proteins plays a major role in regulation of eukaryotic gene expression. This process is controlled by histone acetyltransferases (HATs/KATs) found in multiprotein complexes that are recruited to chromatin by the scaffolding subunit transformation/transcription domain-associated protein (TRRAP). TRRAP is evolutionarily conserved and is among the top five genes intolerant to missense variation. Through an international collaboration, 17 distinct de novo or apparently de novo variants were identified in TRRAP in 24 individuals. A strong genotype-phenotype correlation was observed with two distinct clinical spectra. The first is a complex, multi-systemic syndrome associated with various malformations of the brain, heart, kidneys, and genitourinary system and characterized by a wide range of intellectual functioning; a number of affected individuals have intellectual disability (ID) and markedly impaired basic life functions. Individuals with this phenotype had missense variants clustering around the c.3127G>A p.(Ala1043Thr) variant identified in five individuals. The second spectrum manifested with autism spectrum disorder (ASD) and/or ID and epilepsy. Facial dysmorphism was seen in both groups and included upslanted palpebral fissures, epicanthus, telecanthus, a wide nasal bridge and ridge, a broad and smooth philtrum, and a thin upper lip. RNA sequencing analysis of skin fibroblasts derived from affected individuals skin fibroblasts showed significant changes in the expression of several genes implicated in neuronal function and ion transport. Thus, we describe here the clinical spectrum associated with TRRAP pathogenic missense variants, and we suggest a genotype-phenotype correlation useful for clinical evaluation of the pathogenicity of the variants.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Transtorno Autístico/etiologia , Deficiência Intelectual/etiologia , Mutação de Sentido Incorreto , Proteínas Nucleares/genética , Adolescente , Adulto , Sequência de Aminoácidos , Transtorno Autístico/metabolismo , Transtorno Autístico/patologia , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Humanos , Lactente , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Masculino , Prognóstico , Homologia de Sequência , Síndrome , Adulto Jovem
9.
Am J Hum Genet ; 104(1): 164-178, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30580808

RESUMO

SMARCC2 (BAF170) is one of the invariable core subunits of the ATP-dependent chromatin remodeling BAF (BRG1-associated factor) complex and plays a crucial role in embryogenesis and corticogenesis. Pathogenic variants in genes encoding other components of the BAF complex have been associated with intellectual disability syndromes. Despite its significant biological role, variants in SMARCC2 have not been directly associated with human disease previously. Using whole-exome sequencing and a web-based gene-matching program, we identified 15 individuals with variable degrees of neurodevelopmental delay and growth retardation harboring one of 13 heterozygous variants in SMARCC2, most of them novel and proven de novo. The clinical presentation overlaps with intellectual disability syndromes associated with other BAF subunits, such as Coffin-Siris and Nicolaides-Baraitser syndromes and includes prominent speech impairment, hypotonia, feeding difficulties, behavioral abnormalities, and dysmorphic features such as hypertrichosis, thick eyebrows, thin upper lip vermilion, and upturned nose. Nine out of the fifteen individuals harbor variants in the highly conserved SMARCC2 DNA-interacting domains (SANT and SWIRM) and present with a more severe phenotype. Two of these individuals present cardiac abnormalities. Transcriptomic analysis of fibroblasts from affected individuals highlights a group of differentially expressed genes with possible roles in regulation of neuronal development and function, namely H19, SCRG1, RELN, and CACNB4. Our findings suggest a novel SMARCC2-related syndrome that overlaps with neurodevelopmental disorders associated with variants in BAF-complex subunits.


Assuntos
Deficiências do Desenvolvimento/complicações , Deficiências do Desenvolvimento/genética , Deficiência Intelectual/complicações , Deficiência Intelectual/genética , Mutação , Fatores de Transcrição/genética , Anormalidades Múltiplas/genética , Adolescente , Criança , Pré-Escolar , Proteínas de Ligação a DNA , Face/anormalidades , Feminino , Deformidades Congênitas da Mão/genética , Humanos , Masculino , Micrognatismo/genética , Pescoço/anormalidades , Proteína Reelina , Síndrome
10.
Genet Med ; 24(6): 1227-1237, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35300924

RESUMO

PURPOSE: This study aimed to describe the phenotypic and molecular characteristics of ARCN1-related syndrome. METHODS: Patients with ARCN1 variants were identified, and clinician researchers were connected using GeneMatcher and physician referrals. Clinical histories were collected from each patient. RESULTS: In total, we identified 14 cases of ARCN1-related syndrome, (9 pediatrics, and 5 fetal cases from 3 families). The clinical features these newly identified cases were compared to 6 previously reported cases for a total of 20 cases. Intrauterine growth restriction, micrognathia, and short stature were present in all patients. Other common features included prematurity (11/15, 73.3%), developmental delay (10/14, 71.4%), genitourinary malformations in males (6/8, 75%), and microcephaly (12/15, 80%). Novel features of ARCN1-related syndrome included transient liver dysfunction and specific glycosylation abnormalities during illness, giant cell hepatitis, hepatoblastoma, cataracts, and lethal skeletal manifestations. Developmental delay was seen in 73% of patients, but only 3 patients had intellectual disability, which is less common than previously reported. CONCLUSION: ARCN1-related syndrome presents with a wide clinical spectrum ranging from a severe embryonic lethal syndrome to a mild syndrome with intrauterine growth restriction, micrognathia, and short stature without intellectual disability. Patients with ARCN1-related syndrome should be monitored for liver dysfunction during illness, cataracts, and hepatoblastoma. Additional research to further define the phenotypic spectrum and possible genotype-phenotype correlations are required.


Assuntos
Catarata , Nanismo , Hepatoblastoma , Deficiência Intelectual , Neoplasias Hepáticas , Micrognatismo , Criança , Feminino , Retardo do Crescimento Fetal/genética , Humanos , Deficiência Intelectual/genética , Masculino , Fenótipo , Síndrome
11.
Am J Hum Genet ; 103(2): 245-260, 2018 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-30057031

RESUMO

Interferon regulatory factor 2 binding protein-like (IRF2BPL) encodes a member of the IRF2BP family of transcriptional regulators. Currently the biological function of this gene is obscure, and the gene has not been associated with a Mendelian disease. Here we describe seven individuals who carry damaging heterozygous variants in IRF2BPL and are affected with neurological symptoms. Five individuals who carry IRF2BPL nonsense variants resulting in a premature stop codon display severe neurodevelopmental regression, hypotonia, progressive ataxia, seizures, and a lack of coordination. Two additional individuals, both with missense variants, display global developmental delay and seizures and a relatively milder phenotype than those with nonsense alleles. The IRF2BPL bioinformatics signature based on population genomics is consistent with a gene that is intolerant to variation. We show that the fruit-fly IRF2BPL ortholog, called pits (protein interacting with Ttk69 and Sin3A), is broadly detected, including in the nervous system. Complete loss of pits is lethal early in development, whereas partial knockdown with RNA interference in neurons leads to neurodegeneration, revealing a requirement for this gene in proper neuronal function and maintenance. The identified IRF2BPL nonsense variants behave as severe loss-of-function alleles in this model organism, and ectopic expression of the missense variants leads to a range of phenotypes. Taken together, our results show that IRF2BPL and pits are required in the nervous system in humans and flies, and their loss leads to a range of neurological phenotypes in both species.

12.
Genet Med ; 23(2): 259-271, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33093671

RESUMO

PURPOSE: The NIH Undiagnosed Diseases Network (UDN) evaluates participants with disorders that have defied diagnosis, applying personalized clinical and genomic evaluations and innovative research. The clinical sites of the UDN are essential to advancing the UDN mission; this study assesses their contributions relative to standard clinical practices. METHODS: We analyzed retrospective data from four UDN clinical sites, from July 2015 to September 2019, for diagnoses, new disease gene discoveries and the underlying investigative methods. RESULTS: Of 791 evaluated individuals, 231 received 240 diagnoses and 17 new disease-gene associations were recognized. Straightforward diagnoses on UDN exome and genome sequencing occurred in 35% (84/240). We considered these tractable in standard clinical practice, although genome sequencing is not yet widely available clinically. The majority (156/240, 65%) required additional UDN-driven investigations, including 90 diagnoses that occurred after prior nondiagnostic exome sequencing and 45 diagnoses (19%) that were nongenetic. The UDN-driven investigations included complementary/supplementary phenotyping, innovative analyses of genomic variants, and collaborative science for functional assays and animal modeling. CONCLUSION: Investigations driven by the clinical sites identified diagnostic and research paradigms that surpass standard diagnostic processes. The new diagnoses, disease gene discoveries, and delineation of novel disorders represent a model for genomic medicine and science.


Assuntos
Doenças não Diagnosticadas , Animais , Genômica , Humanos , Doenças Raras/diagnóstico , Doenças Raras/genética , Estudos Retrospectivos , Sequenciamento do Exoma
13.
Genet Med ; 23(4): 653-660, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33299146

RESUMO

PURPOSE: This study aims to provide a comprehensive description of the phenotypic and genotypic spectrum of SNAP25 developmental and epileptic encephalopathy (SNAP25-DEE) by reviewing newly identified and previously reported individuals. METHODS: Individuals harboring heterozygous missense or loss-of-function variants in SNAP25 were assembled through collaboration with international colleagues, matchmaking platforms, and literature review. For each individual, detailed phenotyping, classification, and structural modeling of the identified variant were performed. RESULTS: The cohort comprises 23 individuals with pathogenic or likely pathogenic de novo variants in SNAP25. Intellectual disability and early-onset epilepsy were identified as the core symptoms of SNAP25-DEE, with recurrent findings of movement disorders, cerebral visual impairment, and brain atrophy. Structural modeling for all variants predicted possible functional defects concerning SNAP25 or impaired interaction with other components of the SNARE complex. CONCLUSION: We provide a comprehensive description of SNAP25-DEE with intellectual disability and early-onset epilepsy mostly occurring before the age of two years. These core symptoms and additional recurrent phenotypes show an overlap to genes encoding other components or associated proteins of the SNARE complex such as STX1B, STXBP1, or VAMP2. Thus, these findings advance the concept of a group of neurodevelopmental disorders that may be termed "SNAREopathies."


Assuntos
Encefalopatias , Epilepsia , Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Proteína 25 Associada a Sinaptossoma/genética , Pré-Escolar , Epilepsia/genética , Humanos , Transtornos do Neurodesenvolvimento/genética , Fenótipo
14.
Am J Med Genet A ; 185(8): 2417-2433, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34042254

RESUMO

Biallelic loss-of-function variants in the thrombospondin-type laminin G domain and epilepsy-associated repeats (TSPEAR) gene have recently been associated with ectodermal dysplasia and hearing loss. The first reports describing a TSPEAR disease association identified this gene is a cause of nonsyndromic hearing loss, but subsequent reports involving additional affected families have questioned this evidence and suggested a stronger association with ectodermal dysplasia. To clarify genotype-phenotype associations for TSPEAR variants, we characterized 13 individuals with biallelic TSPEAR variants. Individuals underwent either exome sequencing or panel-based genetic testing. Nearly all of these newly reported individuals (11/13) have phenotypes that include tooth agenesis or ectodermal dysplasia, while three newly reported individuals have hearing loss. Of the individuals displaying hearing loss, all have additional variants in other hearing-loss-associated genes, specifically TMPRSS3, GJB2, and GJB6, that present competing candidates for their hearing loss phenotype. When presented alongside previous reports, the overall evidence supports the association of TSPEAR variants with ectodermal dysplasia and tooth agenesis features but creates significant doubt as to whether TSPEAR variants are a monogenic cause of hearing loss. Further functional evidence is needed to evaluate this phenotypic association.


Assuntos
Anodontia/diagnóstico , Anodontia/genética , Displasia Ectodérmica/diagnóstico , Displasia Ectodérmica/genética , Variação Genética , Fenótipo , Proteínas/genética , Alelos , Substituição de Aminoácidos , Estudos de Coortes , Feminino , Estudos de Associação Genética , Loci Gênicos , Humanos , Masculino , Mutação , Linhagem , Radiografia
15.
Am J Med Genet A ; 185(8): 2384-2390, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34003604

RESUMO

TCF7L2 encodes transcription factor 7-like 2 (OMIM 602228), a key mediator of the evolutionary conserved canonical Wnt signaling pathway. Although several large-scale sequencing studies have implicated TCF7L2 in intellectual disability and autism, both the genetic mechanism and clinical phenotype have remained incompletely characterized. We present here a comprehensive genetic and phenotypic description of 11 individuals who have been identified to carry de novo variants in TCF7L2, both truncating and missense. Missense variation is clustered in or near a high mobility group box domain, involving this region in these variants' pathogenicity. All affected individuals present with developmental delays in childhood, but most ultimately achieved normal intelligence or had only mild intellectual disability. Myopia was present in approximately half of the individuals, and some individuals also possessed dysmorphic craniofacial features, orthopedic abnormalities, or neuropsychiatric comorbidities including autism and attention-deficit/hyperactivity disorder (ADHD). We thus present an initial clinical and genotypic spectrum associated with variation in TCF7L2, which will be important in informing both medical management and future research.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética , Transtornos do Neurodesenvolvimento/diagnóstico , Transtornos do Neurodesenvolvimento/genética , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Adolescente , Alelos , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética/métodos , Humanos , Masculino , Mutação de Sentido Incorreto , Fases de Leitura Aberta , Fenótipo , Síndrome
16.
Epilepsia ; 62(7): e103-e109, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34041744

RESUMO

CSNK2B has recently been implicated as a disease gene for neurodevelopmental disability (NDD) and epilepsy. Information about developmental outcomes has been limited by the young age and short follow-up for many of the previously reported cases, and further delineation of the spectrum of associated phenotypes is needed. We present 25 new patients with variants in CSNK2B and refine the associated NDD and epilepsy phenotypes. CSNK2B variants were identified by research or clinical exome sequencing, and investigators from different centers were connected via GeneMatcher. Most individuals had developmental delay and generalized epilepsy with onset in the first 2 years. However, we found a broad spectrum of phenotypic severity, ranging from early normal development with pharmacoresponsive seizures to profound intellectual disability with intractable epilepsy and recurrent refractory status epilepticus. These findings suggest that CSNK2B should be considered in the diagnostic evaluation of patients with a broad range of NDD with treatable or intractable seizures.


Assuntos
Deficiências do Desenvolvimento/genética , Epilepsia Generalizada/genética , Adolescente , Adulto , Idade de Início , Criança , Pré-Escolar , Deficiências do Desenvolvimento/fisiopatologia , Epilepsias Mioclônicas/diagnóstico , Epilepsias Mioclônicas/etiologia , Epilepsias Mioclônicas/genética , Epilepsia Generalizada/diagnóstico , Epilepsia Generalizada/etiologia , Exoma/genética , Feminino , Variação Genética , Humanos , Lactente , Deficiência Intelectual/etiologia , Deficiência Intelectual/genética , Masculino , Mutação/genética , Fenótipo , Estado Epiléptico/diagnóstico , Estado Epiléptico/etiologia , Estado Epiléptico/genética , Adulto Jovem
17.
PLoS Genet ; 14(11): e1007671, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30500825

RESUMO

Mutations that alter signaling of RAS/MAPK-family proteins give rise to a group of Mendelian diseases known as RASopathies. However, among RASopathies, the matrix of genotype-phenotype relationships is still incomplete, in part because there are many RAS-related proteins and in part because the phenotypic consequences may be variable and/or pleiotropic. Here, we describe a cohort of ten cases, drawn from six clinical sites and over 16,000 sequenced probands, with de novo protein-altering variation in RALA, a RAS-like small GTPase. All probands present with speech and motor delays, and most have intellectual disability, low weight, short stature, and facial dysmorphism. The observed rate of de novo RALA variants in affected probands is significantly higher (p = 4.93 x 10(-11)) than expected from the estimated random mutation rate. Further, all de novo variants described here affect residues within the GTP/GDP-binding region of RALA; in fact, six alleles arose at only two codons, Val25 and Lys128. The affected residues are highly conserved across both RAL- and RAS-family genes, are devoid of variation in large human population datasets, and several are homologous to positions at which disease-associated variants have been observed in other GTPase genes. We directly assayed GTP hydrolysis and RALA effector-protein binding of the observed variants, and found that all but one tested variant significantly reduced both activities compared to wild-type. The one exception, S157A, reduced GTP hydrolysis but significantly increased RALA-effector binding, an observation similar to that seen for oncogenic RAS variants. These results show the power of data sharing for the interpretation and analysis of rare variation, expand the spectrum of molecular causes of developmental disability to include RALA, and provide additional insight into the pathogenesis of human disease caused by mutations in small GTPases.


Assuntos
Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Proteínas Mitocondriais/genética , Mutação , Domínios e Motivos de Interação entre Proteínas/genética , Proteínas ral de Ligação ao GTP/genética , Proteínas ras/genética , Fácies , Genótipo , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Humanos , Proteínas Mitocondriais/química , Modelos Moleculares , Mutação de Sentido Incorreto , Fenótipo , Conformação Proteica , Proteínas ral de Ligação ao GTP/química , Proteínas ras/química
18.
Hum Mol Genet ; 27(14): 2454-2465, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29726930

RESUMO

The 17 genes of the T-box family are transcriptional regulators that are involved in all stages of embryonic development, including craniofacial, brain, heart, skeleton and immune system. Malformation syndromes have been linked to many of the T-box genes. For example, haploinsufficiency of TBX1 is responsible for many structural malformations in DiGeorge syndrome caused by a chromosome 22q11.2 deletion. We report four individuals with an overlapping spectrum of craniofacial dysmorphisms, cardiac anomalies, skeletal malformations, immune deficiency, endocrine abnormalities and developmental impairments, reminiscent of DiGeorge syndrome, who are heterozygotes for TBX2 variants. The p.R20Q variant is shared by three affected family members in an autosomal dominant manner; the fourth unrelated individual has a de novo p.R305H mutation. Bioinformatics analyses indicate that these variants are rare and predict them to be damaging. In vitro transcriptional assays in cultured cells show that both variants result in reduced transcriptional repressor activity of TBX2. We also show that the variants result in reduced protein levels of TBX2. Heterologous over-expression studies in Drosophila demonstrate that both p.R20Q and p.R305H function as partial loss-of-function alleles. Hence, these and other data suggest that TBX2 is a novel candidate gene for a new multisystem malformation disorder.


Assuntos
Deficiências do Desenvolvimento/genética , Síndrome de DiGeorge/genética , Predisposição Genética para Doença , Proteínas com Domínio T/genética , Adulto , Animais , Anormalidades Cardiovasculares/genética , Anormalidades Cardiovasculares/fisiopatologia , Sistema Cardiovascular/fisiopatologia , Criança , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/fisiopatologia , Deficiências do Desenvolvimento/fisiopatologia , Síndrome de DiGeorge/fisiopatologia , Modelos Animais de Doenças , Drosophila melanogaster , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Haploinsuficiência/genética , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/fisiopatologia , Humanos , Camundongos , Linhagem , Gravidez , Adulto Jovem , Peixe-Zebra
19.
EMBO J ; 35(2): 193-207, 2016 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-26658110

RESUMO

Telomeres and tumor suppressor protein TP53 (p53) function in genome protection, but a direct role of p53 at telomeres has not yet been described. Here, we have identified non-canonical p53-binding sites within the human subtelomeres that suppress the accumulation of DNA damage at telomeric repeat DNA. These non-canonical subtelomeric p53-binding sites conferred transcription enhancer-like functions that include an increase in local histone H3K9 and H3K27 acetylation and stimulation of subtelomeric transcripts, including telomere repeat-containing RNA (TERRA). p53 suppressed formation of telomere-associated γH2AX and prevented telomere DNA degradation in response to DNA damage stress. Our findings indicate that p53 provides a direct chromatin-associated protection to human telomeres, as well as other fragile genomic sites. We propose that p53-associated chromatin modifications enhance local DNA repair or protection to provide a previously unrecognized tumor suppressor function of p53.


Assuntos
Proteínas de Transporte/metabolismo , Dano ao DNA/genética , Telômero/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteínas de Transporte/genética , Células HCT116 , Humanos , Ligação Proteica , Telômero/genética , Proteína Supressora de Tumor p53/genética
20.
Am J Hum Genet ; 100(1): 128-137, 2017 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-28017372

RESUMO

Early B cell factor 3 (EBF3) is a member of the highly evolutionarily conserved Collier/Olf/EBF (COE) family of transcription factors. Prior studies on invertebrate and vertebrate animals have shown that EBF3 homologs are essential for survival and that loss-of-function mutations are associated with a range of nervous system developmental defects, including perturbation of neuronal development and migration. Interestingly, aristaless-related homeobox (ARX), a homeobox-containing transcription factor critical for the regulation of nervous system development, transcriptionally represses EBF3 expression. However, human neurodevelopmental disorders related to EBF3 have not been reported. Here, we describe three individuals who are affected by global developmental delay, intellectual disability, and expressive speech disorder and carry de novo variants in EBF3. Associated features seen in these individuals include congenital hypotonia, structural CNS malformations, ataxia, and genitourinary abnormalities. The de novo variants affect a single conserved residue in a zinc finger motif crucial for DNA binding and are deleterious in a fly model. Our findings indicate that mutations in EBF3 cause a genetic neurodevelopmental syndrome and suggest that loss of EBF3 function might mediate a subset of neurologic phenotypes shared by ARX-related disorders, including intellectual disability, abnormal genitalia, and structural CNS malformations.


Assuntos
Mutação , Transtornos do Neurodesenvolvimento/genética , Fatores de Transcrição/genética , Anormalidades Múltiplas/genética , Ataxia/genética , Sistema Nervoso Central/anormalidades , Criança , Pré-Escolar , Deficiências do Desenvolvimento/genética , Feminino , Genitália/anormalidades , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/genética , Masculino , Hipotonia Muscular/genética , Distúrbios da Fala/genética , Síndrome , Dedos de Zinco/genética
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