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1.
Genet Med ; 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31263215

RESUMO

PURPOSE: Haploinsufficiency of DYRK1A causes a recognizable clinical syndrome. The goal of this paper is to investigate congenital anomalies of the kidney and urinary tract (CAKUT) and genital defects (GD) in patients with DYRK1A variants. METHODS: A large database of clinical exome sequencing (ES) was queried for de novo DYRK1A variants and CAKUT/GD phenotypes were characterized. Xenopus laevis (frog) was chosen as a model organism to assess Dyrk1a's role in renal development. RESULTS: Phenotypic details and variants of 19 patients were compiled after an initial observation that one patient with a de novo pathogenic variant in DYRK1A had GD. CAKUT/GD data were available from 15 patients, 11 of whom presented with CAKUT/GD. Studies in Xenopus embryos demonstrated that knockdown of Dyrk1a, which is expressed in forming nephrons, disrupts the development of segments of embryonic nephrons, which ultimately give rise to the entire genitourinary (GU) tract. These defects could be rescued by coinjecting wild-type human DYRK1A RNA, but not with DYRK1AR205* or DYRK1AL245R RNA. CONCLUSION: Evidence supports routine GU screening of all individuals with de novo DYRK1A pathogenic variants to ensure optimized clinical management. Collectively, the reported clinical data and loss-of-function studies in Xenopus substantiate a novel role for DYRK1A in GU development.

2.
Am J Hum Genet ; 104(2): 319-330, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30639322

RESUMO

ZMIZ1 is a coactivator of several transcription factors, including p53, the androgen receptor, and NOTCH1. Here, we report 19 subjects with intellectual disability and developmental delay carrying variants in ZMIZ1. The associated features include growth failure, feeding difficulties, microcephaly, facial dysmorphism, and various other congenital malformations. Of these 19, 14 unrelated subjects carried de novo heterozygous single-nucleotide variants (SNVs) or single-base insertions/deletions, 3 siblings harbored a heterozygous single-base insertion, and 2 subjects had a balanced translocation disrupting ZMIZ1 or involving a regulatory region of ZMIZ1. In total, we identified 13 point mutations that affect key protein regions, including a SUMO acceptor site, a central disordered alanine-rich motif, a proline-rich domain, and a transactivation domain. All identified variants were absent from all available exome and genome databases. In vitro, ZMIZ1 showed impaired coactivation of the androgen receptor. In vivo, overexpression of ZMIZ1 mutant alleles in developing mouse brains using in utero electroporation resulted in abnormal pyramidal neuron morphology, polarization, and positioning, underscoring the importance of ZMIZ1 in neural development and supporting mutations in ZMIZ1 as the cause of a rare neurodevelopmental syndrome.


Assuntos
Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Mutação Puntual , Fatores de Transcrição/genética , Alelos , Animais , Criança , Pré-Escolar , Deficiências do Desenvolvimento/patologia , Feminino , Humanos , Lactente , Deficiência Intelectual/patologia , Masculino , Camundongos , Síndrome , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
3.
Ann Neurol ; 84(5): 788-795, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30269351

RESUMO

NBEA is a candidate gene for autism, and de novo variants have been reported in neurodevelopmental disease (NDD) cohorts. However, NBEA has not been rigorously evaluated as a disease gene, and associated phenotypes have not been delineated. We identified 24 de novo NBEA variants in patients with NDD, establishing NBEA as an NDD gene. Most patients had epilepsy with onset in the first few years of life, often characterized by generalized seizure types, including myoclonic and atonic seizures. Our data show a broader phenotypic spectrum than previously described, including a myoclonic-astatic epilepsy-like phenotype in a subset of patients. Ann Neurol 2018;84:796-803.

4.
Hum Mol Genet ; 27(14): 2454-2465, 2018 Jul 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.

5.
Genet Med ; 19(1): 45-52, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27195816

RESUMO

PURPOSE: Truncating mutations in the maternally imprinted, paternally expressed gene MAGEL2, which is located in the Prader-Willi critical region 15q11-13, have recently been reported to cause Schaaf-Yang syndrome, a Prader-Willi-like disease that manifests as developmental delay/intellectual disability, hypotonia, feeding difficulties, and autism spectrum disorder. The causality of the reported variants in the context of the patients' phenotypes was questioned, as MAGEL2 whole-gene deletions seem to cause little or no clinical phenotype. METHODS: Here we report a total of 18 newly identified individuals with Schaaf-Yang syndrome from 14 families, including 1 family with 3 individuals found to be affected with a truncating variant of MAGEL2, 11 individuals who are clinically affected but were not tested molecularly, and a presymptomatic fetal sibling carrying the pathogenic MAGEL2 variant. RESULTS: All cases harbor truncating mutations of MAGEL2, and nucleotides c.1990-1996 arise as a mutational hotspot, with 10 individuals and 1 fetus harboring a c.1996dupC (p.Q666fs) mutation and 2 fetuses harboring a c.1996delC (p.Q666fs) mutation. The phenotypic spectrum of Schaaf-Yang syndrome ranges from fetal akinesia to neurobehavioral disease and contractures of the small finger joints. CONCLUSION: This study provides strong evidence for the pathogenicity of truncating mutations of the paternal allele of MAGEL2, refines the associated clinical phenotypes, and highlights implications for genetic counseling for affected families.Genet Med 19 1, 45-52.


Assuntos
Transtorno do Espectro Autista/genética , Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Síndrome de Prader-Willi/genética , Proteínas/genética , Adolescente , Adulto , Transtorno do Espectro Autista/fisiopatologia , Criança , Pré-Escolar , Cromossomos Humanos Par 15 , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Expressão Gênica , Impressão Genômica , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/fisiopatologia , Masculino , Mutação , Fenótipo , Síndrome de Prader-Willi/fisiopatologia
6.
Am J Med Genet A ; 170(3): 670-5, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26842493

RESUMO

We report on 19 individuals with a recurrent de novo c.607C>T mutation in PACS1. This specific mutation gives rise to a recognizable intellectual disability syndrome. There is a distinctive facial appearance (19/19), characterized by full and arched eyebrows, hypertelorism with downslanting palpebral fissures, long eye lashes, ptosis, low set and simple ears, bulbous nasal tip, wide mouth with downturned corners and a thin upper lip with an unusual "wavy" profile, flat philtrum, and diastema of the teeth. Intellectual disability, ranging from mild to moderate, was present in all. Hypotonia is common in infancy (8/19). Seizures are frequent (12/19) and respond well to anticonvulsive medication. Structural malformations are common, including heart (10/19), brain (12/16), eye (10/19), kidney (3/19), and cryptorchidism (6/12 males). Feeding dysfunction is presenting in infancy with failure to thrive (5/19), gastroesophageal reflux (6/19), and gastrostomy tube placement (4/19). There is persistence of oral motor dysfunction. We provide suggestions for clinical work-up and management and hope that the present study will facilitate clinical recognition of further cases.


Assuntos
Anormalidades Múltiplas/genética , Deficiência Intelectual/genética , Mutação Puntual , Convulsões/genética , Proteínas de Transporte Vesicular/genética , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/tratamento farmacológico , Anormalidades Múltiplas/patologia , Adolescente , Anticonvulsivantes/uso terapêutico , Criança , Pré-Escolar , Facies , Insuficiência de Crescimento/diagnóstico , Insuficiência de Crescimento/tratamento farmacológico , Insuficiência de Crescimento/genética , Insuficiência de Crescimento/patologia , Feminino , Expressão Gênica , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/tratamento farmacológico , Deficiência Intelectual/patologia , Masculino , Hipotonia Muscular/diagnóstico , Hipotonia Muscular/tratamento farmacológico , Hipotonia Muscular/genética , Hipotonia Muscular/patologia , Convulsões/diagnóstico , Convulsões/tratamento farmacológico , Convulsões/patologia , Índice de Gravidade de Doença , Síndrome , Adulto Jovem
7.
Eur J Hum Genet ; 24(5): 652-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26306646

RESUMO

The Koolen-de Vries syndrome (KdVS; OMIM #610443), also known as the 17q21.31 microdeletion syndrome, is a clinically heterogeneous disorder characterised by (neonatal) hypotonia, developmental delay, moderate intellectual disability, and characteristic facial dysmorphism. Expressive language development is particularly impaired compared with receptive language or motor skills. Other frequently reported features include social and friendly behaviour, epilepsy, musculoskeletal anomalies, congenital heart defects, urogenital malformations, and ectodermal anomalies. The syndrome is caused by a truncating variant in the KAT8 regulatory NSL complex unit 1 (KANSL1) gene or by a 17q21.31 microdeletion encompassing KANSL1. Herein we describe a novel cohort of 45 individuals with KdVS of whom 33 have a 17q21.31 microdeletion and 12 a single-nucleotide variant (SNV) in KANSL1 (19 males, 26 females; age range 7 months to 50 years). We provide guidance about the potential pitfalls in the laboratory testing and emphasise the challenges of KANSL1 variant calling and DNA copy number analysis in the complex 17q21.31 region. Moreover, we present detailed phenotypic information, including neuropsychological features, that contribute to the broad phenotypic spectrum of the syndrome. Comparison of the phenotype of both the microdeletion and SNV patients does not show differences of clinical importance, stressing that haploinsufficiency of KANSL1 is sufficient to cause the full KdVS phenotype.


Assuntos
Anormalidades Múltiplas/diagnóstico , Deficiência Intelectual/diagnóstico , Proteínas Nucleares/genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Anormalidades Múltiplas/genética , Adolescente , Adulto , Criança , Deleção Cromossômica , Cromossomos Humanos Par 17/genética , Feminino , Humanos , Deficiência Intelectual/genética , Masculino , Pessoa de Meia-Idade
8.
Am J Hum Genet ; 97(5): 744-53, 2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-26477546

RESUMO

Joubert syndrome (JBTS) is a primarily autosomal-recessive disorder characterized by a distinctive mid-hindbrain and cerebellar malformation, oculomotor apraxia, irregular breathing, developmental delay, and ataxia. JBTS is a genetically heterogeneous ciliopathy. We sought to characterize the genetic landscape associated with JBTS in the French Canadian (FC) population. We studied 43 FC JBTS subjects from 35 families by combining targeted and exome sequencing. We identified pathogenic (n = 32 families) or possibly pathogenic (n = 2 families) variants in genes previously associated with JBTS in all of these subjects, except for one. In the latter case, we found a homozygous splice-site mutation (c.735+2T>C) in CEP104. Interestingly, we identified two additional non-FC JBTS subjects with mutations in CEP104; one of these subjects harbors a maternally inherited nonsense mutation (c.496C>T [p.Arg166*]) and a de novo splice-site mutation (c.2572-2A>G), whereas the other bears a homozygous frameshift mutation (c.1328_1329insT [p.Tyr444fs*3]) in CEP104. Previous studies have shown that CEP104 moves from the mother centriole to the tip of the primary cilium during ciliogenesis. Knockdown of CEP104 in retinal pigment epithelial (RPE1) cells resulted in severe defects in ciliogenesis. These observations suggest that CEP104 acts early during cilia formation by regulating the conversion of the mother centriole into the cilia basal body. We conclude that disruption of CEP104 causes JBTS. Our study also reveals that the cause of JBTS has been elucidated in the great majority of our FC subjects (33/35 [94%] families), even though JBTS shows substantial locus and allelic heterogeneity in this population.


Assuntos
Cerebelo/anormalidades , Cílios/patologia , Proteínas Associadas aos Microtúbulos/genética , Mutação/genética , Retina/anormalidades , Anormalidades Múltiplas/epidemiologia , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Adolescente , Adulto , Canadá/epidemiologia , Cerebelo/patologia , Criança , Pré-Escolar , Cílios/metabolismo , Exoma/genética , Anormalidades do Olho/epidemiologia , Anormalidades do Olho/genética , Anormalidades do Olho/patologia , Feminino , Seguimentos , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Lactente , Recém-Nascido , Doenças Renais Císticas/epidemiologia , Doenças Renais Císticas/genética , Doenças Renais Císticas/patologia , Masculino , Linhagem , Prognóstico , Retina/patologia , Adulto Jovem
9.
Am J Hum Genet ; 95(5): 579-83, 2014 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-25439098

RESUMO

5q31.3 microdeletion syndrome is characterized by neonatal hypotonia, encephalopathy with or without epilepsy, and severe developmental delay, and the minimal critical deletion interval harbors three genes. We describe 11 individuals with clinical features of 5q31.3 microdeletion syndrome and de novo mutations in PURA, encoding transcriptional activator protein Pur-α, within the critical region. These data implicate causative PURA mutations responsible for the severe neurological phenotypes observed in this syndrome.


Assuntos
Anormalidades Múltiplas/genética , Deleção Cromossômica , Cromossomos Humanos Par 5/genética , Proteínas de Ligação a DNA/genética , Hipotonia Muscular/genética , Convulsões/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Caenorhabditis elegans/genética , Mapeamento Cromossômico , Humanos , Dados de Sequência Molecular , Mutação/genética , Análise de Sequência de DNA , Síndrome
10.
Am J Med Genet A ; 161A(11): 2762-76, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24123776

RESUMO

Sensenbrenner syndrome, also known as cranioectodermal dysplasia, is a rare multiple anomaly syndrome with distinctive craniofacial appearance, skeletal, ectodermal, connective tissue, renal, and liver anomalies. Dramatic advances with next-generation sequencing have expanded its phenotypic variability and molecular heterogeneity. We review 39 patients including two new patients, one with compound heterozygous novel mutations in WDR35 and a previously unreported multisutural craniosynostosis that may be a part of Sensenbrenner syndrome. In 14 of 25 (56.0%) patients pathogenic mutations have been identified in 4 different genes that regulate (intraflagellar) cilia transport. We compared Sensenbrenner syndrome to asphyxiating thoracic dystrophy-Jeune syndrome (ATD-JS) and other ciliopathies. Our analyses showed that the high anterior hairline, forehead bossing and dolichocephaly (accompanied by sagittal craniosynostosis in more than half of the patients) occur in almost all patients with Sensenbrenner syndrome. Metaphyseal dysplasia with narrow thorax, proximal limb shortness, and short fingers are typical of Sensenbrenner syndrome and ATD-JS. Respiratory complications have been reported in both syndromes, usually less severe with Sensenbrenner syndrome. Proposed diagnostic criteria for Sensenbrenner syndrome include the distinctive craniofacial appearance, ubiquitous brachydactyly and ectodermal anomalies, and sagittal craniosynostosis. Mild heart defects have been noted, but there have been no atrioventricular canal or heterotaxy defects that are common in Ellis-Van Creveld syndrome. We anticipate that the steady identification of molecularly defined patients may allow correlation of phenotype and genotype. Additional natural history data will improve genetic counseling and current guidelines.


Assuntos
Osso e Ossos/anormalidades , Craniossinostoses/diagnóstico , Craniossinostoses/genética , Displasia Ectodérmica/diagnóstico , Displasia Ectodérmica/genética , Hibridização Genômica Comparativa , Análise Mutacional de DNA , Humanos , Lactente , Recém-Nascido , Cariotipagem , Masculino , Fenótipo
11.
Am J Med Genet A ; 146A(8): 1042-8, 2008 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-18348260

RESUMO

Noonan syndrome is an autosomal dominant disorder with an estimated incidence of 1 in 1,000 to 1 in 2,500 live births. It is characterized by postnatal-onset short stature, characteristic facial changes, webbed neck, pectus carinatum, or excavatum, congenital heart defects, and bleeding abnormalities. Gain-of-function mutations in the PTPN11, KRAS, SOS1, and RAF1 genes that are components of the RAS/MEPK signaling pathway are identified in about 70-85% of individuals with Noonan syndrome. We report here a case of duplication of chromosome region 12q24.11q24.23 identified by array comparative genomic hybridization (aCGH) that includes the PTPN11 gene in a 3-year-old girl with apparent Noonan syndrome. The patient presented with postnatal-onset failure-to-thrive, developmental delay, microcephaly, velopalatal incompetence, pectus excavatum, coarctation of aorta, atrial and ventricular septal defects, decreased muscle tone, and minor facial anomalies consistent with Noonan syndrome. At 3 years of age her speech, gross and fine motor development were at the level of a 12-18 month old child. This degree of developmental delay was atypical for an individual with Noonan syndrome, raising concerns for a chromosomal abnormality. Array-CGH showed an interstitial duplication of 10 Mb including the PTPN11 gene. Sequencing of PTPN11, KRAS, SOS1 and the coding region of RAF1 did not identify mutations. The increased gene dosage of the PTPN11 gene in the form of duplication is expected to have the same consequence as gain-of-function mutations seen in Noonan syndrome. We propose that at least some of the 15-30% of individuals with Noonan syndrome who do not have a mutation by sequencing may have a gain in copy number of PTPN11 and recommend that comprehensive testing for Noonan syndrome should include analysis for copy number changes of PTPN11.


Assuntos
Bandeamento Cromossômico , Cromossomos Humanos Par 12/genética , Duplicação Gênica , Síndrome de Noonan/genética , Pré-Escolar , Feminino , Dosagem de Genes , Humanos , Síndrome de Noonan/fisiopatologia , Hibridização de Ácido Nucleico/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética
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