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1.
PLoS Genet ; 16(12): e1009219, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33382686

RESUMO

Roberts syndrome (RBS) is a rare developmental disorder that can include craniofacial abnormalities, limb malformations, missing digits, intellectual disabilities, stillbirth, and early mortality. The genetic basis for RBS is linked to autosomal recessive loss-of-function mutation of the establishment of cohesion (ESCO) 2 acetyltransferase. ESCO2 is an essential gene that targets the DNA-binding cohesin complex. ESCO2 acetylates alternate subunits of cohesin to orchestrate vital cellular processes that include sister chromatid cohesion, chromosome condensation, transcription, and DNA repair. Although significant advances were made over the last 20 years in our understanding of ESCO2 and cohesin biology, the molecular etiology of RBS remains ambiguous. In this review, we highlight current models of RBS and reflect on data that suggests a novel role for macromolecular damage in the molecular etiology of RBS.


Assuntos
Acetiltransferases/genética , Proteínas Cromossômicas não Histona/genética , Anormalidades Craniofaciais/genética , Dano ao DNA , Ectromelia/genética , Hipertelorismo/genética , Acetiltransferases/metabolismo , Animais , Proteínas Cromossômicas não Histona/metabolismo , Anormalidades Craniofaciais/metabolismo , Ectromelia/metabolismo , Instabilidade Genômica , Humanos , Hipertelorismo/metabolismo
2.
Medicine (Baltimore) ; 99(45): e23033, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33157955

RESUMO

INTRODUCTION: Microdeletion syndromes occur from deletion of 5Mb of a chromosome in approximately 5% of patients with unexplained intellectual disability. Interstitial microdeletions at bands 1p33 and 1p32.2 of the short arm of chromosome 1 are rare and have not been previously reported in relation to disease. PATIENT CONCERNS: We present a case of a 39-month boy with Pierre Robin sequence, development delay/intellectual disability, growth retardation, short stature, leukoencephalopathy, craniofacial dysplasia, and speech delay. The child was referred to the Child health care department in October 2014 for his delayed language development and aggravated aggression. DIAGNOSIS: Molecular diagnostic testing with G-band karyotyping was normal but clinical microarray analysis detected a 10 Mb microdeletion at 1p33p32.2. INTERVENTIONS: The patient received rehabilitation. OUTCOMES: Three candidate genes were pinpointed to the deleted area, including ORC1, SCP2, and DAB1. Phenotype-genotype analysis suggested that these three genes are likely to be responsible for the main phenotypes observed in the patient, such as microcephaly, growth retardation, short stature, leukoencephalopathy, and development delay/intellectual disability. CONCLUSIONS: The spectrum of phenotypes this case presented with are likely to be caused by 1p33p32.2 deletion which could represent a new microdeletion syndrome.


Assuntos
Cariotipagem/métodos , Análise em Microsséries/métodos , Síndrome de Pierre Robin/diagnóstico , Síndrome de Pierre Robin/genética , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Adolescente , Adulto , Proteínas de Transporte/genética , Criança , Pré-Escolar , Deleção Cromossômica , Anormalidades Craniofaciais/diagnóstico , Anormalidades Craniofaciais/genética , Nanismo/diagnóstico , Nanismo/genética , Feminino , Humanos , Lactente , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Transtornos do Desenvolvimento da Linguagem/diagnóstico , Transtornos do Desenvolvimento da Linguagem/genética , Leucoencefalopatias/diagnóstico , Leucoencefalopatias/genética , Masculino , Microcefalia/diagnóstico , Microcefalia/genética , Proteínas do Tecido Nervoso/genética , Complexo de Reconhecimento de Origem/genética , Fenótipo , Síndrome de Pierre Robin/reabilitação
3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(10): 1124-1127, 2020 Oct 10.
Artigo em Chinês | MEDLINE | ID: mdl-32924116

RESUMO

OBJECTIVE: To explore the molecular basis for a child featuring with Floating-Harbor syndrome. METHODS: The 2-year-and-8-month-old child presented with retarded growth and language development. Genomic DNA was extracted from peripheral blood samples from the child and his parents with informed consent and subjected to whole exome sequencing. Suspected variants were verified by Sanger sequencing. Pathogenecity of the variants were predicted by using bioinformatic tools. RESULTS: The child was found to carry a de novo frameshift variant c.7273dupA (p. Thr2425Asnfs*18) in the SRCAP gene. The variant was unreported previously and predicted to be pathogenic by MutationTaster. Analysis using HomoloGene system and MEGA software indicated position 2425 of the SRCAP protein to be highly conserved. Substitution of amino acid (Thr) at this position may cause destruction of three AT-hook domains (Amino acid 2857-2869, 2936-2948 and 3004-3016) and serious damage to the function of SRCAP protein. CONCLUSION: The patient's condition may be attributed to the de novo frameshift variant c.7273dupA (p. Thr2425Asnfs*18) of the SRCAP gene. Above finding can facilitate diagnosis of Floating-Harbor syndrome among Chinese population.


Assuntos
Anormalidades Múltiplas/genética , Adenosina Trifosfatases/genética , Anormalidades Craniofaciais/genética , Mutação da Fase de Leitura , Transtornos do Crescimento/genética , Comunicação Interventricular/genética , Humanos , Lactente , Masculino
4.
Am J Hum Genet ; 107(2): 352-363, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32693025

RESUMO

MORC2 encodes an ATPase that plays a role in chromatin remodeling, DNA repair, and transcriptional regulation. Heterozygous variants in MORC2 have been reported in individuals with autosomal-dominant Charcot-Marie-Tooth disease type 2Z and spinal muscular atrophy, and the onset of symptoms ranges from infancy to the second decade of life. Here, we present a cohort of 20 individuals referred for exome sequencing who harbor pathogenic variants in the ATPase module of MORC2. Individuals presented with a similar phenotype consisting of developmental delay, intellectual disability, growth retardation, microcephaly, and variable craniofacial dysmorphism. Weakness, hyporeflexia, and electrophysiologic abnormalities suggestive of neuropathy were frequently observed but were not the predominant feature. Five of 18 individuals for whom brain imaging was available had lesions reminiscent of those observed in Leigh syndrome, and five of six individuals who had dilated eye exams had retinal pigmentary abnormalities. Functional assays revealed that these MORC2 variants result in hyperactivation of epigenetic silencing by the HUSH complex, supporting their pathogenicity. The described set of morphological, growth, developmental, and neurological findings and medical concerns expands the spectrum of genetic disorders resulting from pathogenic variants in MORC2.


Assuntos
Adenosina Trifosfatases/genética , Anormalidades Craniofaciais/genética , Transtornos do Crescimento/genética , Mutação/genética , Transtornos do Neurodesenvolvimento/genética , Fatores de Transcrição/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Doenças Genéticas Inatas/genética , Heterozigoto , Humanos , Lactente , Deficiência Intelectual/genética , Masculino , Microcefalia/genética , Pessoa de Meia-Idade , Fenótipo , Adulto Jovem
5.
Medicine (Baltimore) ; 99(29): e20574, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32702813

RESUMO

RATIONALE: Schaaf-Yang syndrome, a rare imprinted hereditary disease caused by MAGEL2 variants, manifests as developmental delay/intellectual disability, neonatal hypotonia, feeding difficulties, contractures, and autism spectrum disorder. PATIENT CONCERNS: Patient 1 and 2 were infant girls presenting facial dysmorphisms, contractures of interphalangeal joints, neonatal hypotonia, feeding difficulties, congenital heart diseases, and respiratory complications. Besides, Patient 2 presented with delayed psychomotor development. DIAGNOSIS: Whole-exome sequencing was performed and heterozygous mutations of the MAGEL2 gene were detected in the patients. They were diagnosed as Schaaf-Yang syndrome. INTERVENTIONS: The patients received supportive treatment including mechanical ventilation, parenteral nutrition and gastric tube feeding. OUTCOMES: Whole-exome sequencing revealed de novo heterozygous c.1996dupC pathogenic mutations in the MAGEL2 gene in the 2 patients. They died due to respiratory failure at the age of 20 days and 98 days, respectively. LESSONS: Our results indicate that MAGEL2 variants can cause congenital heart disease and fatal respiratory complications, broadening the phenotypic spectrum and adding to the fatal cases of Schaaf-Yang syndrome. We highly suggest that the MAGEL2 gene should be added to gene-panels or gene-filters in next-generation sequencing-based diagnostics, which is of great significance for early diagnosis and early intervention of Schaaf-Yang syndrome patients.


Assuntos
Anormalidades Múltiplas/genética , Testes Genéticos/métodos , Proteínas/genética , Sequenciamento Completo do Exoma/métodos , Criança , Contratura/genética , Anormalidades Craniofaciais/genética , Deficiências do Desenvolvimento/genética , Evolução Fatal , Transtornos da Alimentação e da Ingestão de Alimentos/genética , Feminino , Articulações dos Dedos/fisiopatologia , Cardiopatias Congênitas/genética , Humanos , Lactente , Recém-Nascido , Masculino , Hipotonia Muscular/genética , Atrofia Muscular/genética , Cuidados Paliativos , Insuficiência Respiratória/genética , Síndrome
6.
Medicine (Baltimore) ; 99(27): e20995, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32629717

RESUMO

RATIONAL: Intestinal lymphangiectasia (IL) is a rare disease characterized by dilatation and rupture of intestinal lymphatic channels leading to protein-losing enteropathy. IL is classified as primary and secondary types. PATIENT CONCERNS: A 3-month-old girl born at term from vaginal delivery with an APGAR score of 10/10 and birth weight of 4.310 g (>97° percentile) was admitted to our hospital because of increasing abdominal tenderness and diarrhea. At first examination, she presented an abdominal circumference of 60 cm, edema of the lower extremities and vulva, and facial dysmorphisms (hypertelorism, flat nasal bridge, flat mid-face). DIAGNOSIS: Once admitted, ultrasonography showed a large amount of ascites, while blood laboratory investigations revealed severe hypoproteinemia, hypoalbuminemia and hypogammaglobulinemia. Lymphoscintigraphy with 99m-Tc-nanocolloid demonstrated abnormal leakage of the tracer in the abdomen as evidence of IL. To detect a possible secondary, exams were performed and demonstrated positive antibody titres for CMV-IgM and IgG in blood and CMV-DNA positivity in blood, urine, saliva, maternal milk, and gastric and duodenal biopsies. Genetic investigations identified the genomic variant c.472C>T of the CCBE1 gene, coding for a protein variant (p.Arg158Cys), in homozygosity. INTERVENTIONS: Total parenteral nutrition was started and continued for a total of 18 days, then gradually bridged by enteral nutrition with a special formula. In addition, antiviral therapy for CMV infection was added first with intravenous ganciclovir for 14 days, resulting in the disappearance of blood viral load after 7 days of therapy and then with valganciclovir per os for another 30 days. OUTCOMES: The clinical course of the child gradually improved. A few days after starting treatments, lower extremities and vulvar edema disappeared, and abdominal circumference gradually decreased to a stable value of 38 cm, without any ultrasonographic signs of ascites left. Moreover, serum albumin and IgG rose to normal values after 3 months (4.3 g/dL and 501 mg/dL, respectively). LESSONS: This case suggests that in presence of IL both primary and secondary causes should be evaluated. On the other hand, genetic diagnosis is crucial not only for diagnosis but also for prognosis in HS. Life expectancy and quality could deeply vary among different gene mutations and protein variants of the same gene. Further studies and case reports are needed to better understand the clinical meaning of these genetic results and the role of CMV as trigger of IL.


Assuntos
Anormalidades Craniofaciais/genética , Linfangiectasia Intestinal/genética , Linfedema/genética , Proteínas de Ligação ao Cálcio/genética , Anormalidades Craniofaciais/diagnóstico , Feminino , Humanos , Lactente , Linfangiectasia Intestinal/diagnóstico , Linfedema/diagnóstico , Mutação , Proteínas Supressoras de Tumor/genética
8.
J Craniofac Surg ; 31(4): e362-e368, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32371695

RESUMO

The purpose of this retrospective study was to assess the genetic and phenotypic features of patients with craniofrontonasal syndrome (CFNS), and the implications of the condition for multidisciplinary management.The subjects were 25 female patients with a mutation of EFNB1, who presented to the Oxford Craniofacial Unit during a 38-year period. Medical records were reviewed for genetic and phenotypic information. Mean duration of follow-up was 12.6 years (range 0-30.7 years).This study examines neurodevelopment in constituent parts, with specific reference to speech, language, and cognition in relation to genotype. Three children had deletions extending beyond the EFNB1 gene; the 2 with available data presented with speech, language, or cognitive delay. The remaining 25 patients had intragenic mutations of EFNB1. Of these 25, those assessed in detail showed variable difficulties with speech and language development; 57% had receptive language difficulties (n = 4/7) and 88% had expressive language difficulties (n = 8/9). 55% presented with speech difficulties (n = 6/11). 2/3 patients with abnormal hearing had speech difficulties; 4/5 with normal hearing had normal speech development. Cognitive assessments indicated that IQ is variable; with full scale IQ ranging from 69 to 100.The complex, multifactorial presentation of patients with CFNS contributed to 41% (n = 7/17) of patients requiring additional educational support.Our results demonstrated significant multidisciplinary input is required, including Speech and Language Therapy, Plastic and Reconstructive Surgery, Genetics, Ear, Nose and Throat, Maxillofacial, Orthodontic, Orthopaedic, Clinical Psychology and Orthoptic teams. The results of this study reinforce the importance of multi-disciplinary long-term follow-up of children with CFNS.


Assuntos
Anormalidades Craniofaciais , Adolescente , Adulto , Criança , Pré-Escolar , Cognição , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/terapia , Efrina-B1/genética , Feminino , Humanos , Lactente , Recém-Nascido , Desenvolvimento da Linguagem , Masculino , Mutação , Estudos Retrospectivos , Distúrbios da Fala/terapia , Fonoterapia , Adulto Jovem
9.
Adv Exp Med Biol ; 1195: 163-166, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32468472

RESUMO

INTRODUCTION: Chromosome 18q deletion syndrome (18q-) is a rare chromosomal disorder with phenotypic variability, including mental deficiency, short stature, hypotonia, cleft palate, and hearing impairment. We present a case with features of 18q- syndrome who had combined 18q partial monosomy and 18p partial trisomy. MATERIAL AND METHODS: A 50-year-old female patient was examined during the genetic counseling of her brother. She had a history of congenital cleft palate and developmental deficiency with hypotonia, hearing loss, and epilepsy until adulthood. Her family history was free of related cases. Karyotype analysis and comparative genomic hybridization array (aCGH) were performed in patient's blood samples. RESULTS: Clinical examination showed features of 18q- syndrome including hypotonia and tremor. Neuropsychological deficiency of moderate cognitive disorder was noticed. The patient's karyotype was normal. The aCGH analysis revealed 8 Mb deletion (del18q22.3q23) and 7.2 Mb duplication (dup18p11.32p11.23). CONCLUSION: Almost all patients' clinical features were associated with 18q- syndrome. There are very few reported cases with similar genotype possibly caused by a de novo unequal recombination mechanism.


Assuntos
Deleção Cromossômica , Transtornos Cromossômicos/genética , Duplicação Cromossômica/genética , Cromossomos Humanos Par 18/genética , Anormalidades Craniofaciais/genética , Hibridização Genômica Comparativa , Feminino , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Fenótipo , Síndrome
10.
Adv Exp Med Biol ; 1195: 237-247, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32468482

RESUMO

MicroRNAs (miRNAs) are small non-coding RNA molecules of about 20-22 nucleotides. After their posttranscriptional maturation, miRNAs are loaded into the ribonucleoprotein complex RISC and modulate gene expression by binding to the 3' untranslated region of their target mRNAs through base-pairing, which in turn triggers mRNA degradation or translational inhibition. There is mounting evidence that miRNAs regulate various biological processes, including cell proliferation, differentiation, and apoptosis. Several studies have shown that miRNAs play an important role in neurogenesis and brain development.This review discusses recent progress on understanding the implication of precisely regulated miRNA expression in normal brain development and function. In addition, it reports known cases of dysregulation of miRNA expression and function implicated in the pathogenesis of neurodevelopmental disorders, craniofacial dysmorphic syndromes, neurodegenerative diseases, and psychiatric disorders. Current knowledge regarding the role of miRNAs in the brain in conjunction with the complex interplay between genetic and epigenetic factors are discussed.


Assuntos
Encéfalo/crescimento & desenvolvimento , Encéfalo/fisiologia , MicroRNAs/metabolismo , Regiões 3' não Traduzidas/genética , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/metabolismo , Humanos , Transtornos Mentais/genética , Transtornos Mentais/metabolismo , MicroRNAs/genética , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Neurogênese/genética
11.
Am J Hum Genet ; 106(5): 596-610, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32243864

RESUMO

Weaver syndrome (WS), an overgrowth/intellectual disability syndrome (OGID), is caused by pathogenic variants in the histone methyltransferase EZH2, which encodes a core component of the Polycomb repressive complex-2 (PRC2). Using genome-wide DNA methylation (DNAm) data for 187 individuals with OGID and 969 control subjects, we show that pathogenic variants in EZH2 generate a highly specific and sensitive DNAm signature reflecting the phenotype of WS. This signature can be used to distinguish loss-of-function from gain-of-function missense variants and to detect somatic mosaicism. We also show that the signature can accurately classify sequence variants in EED and SUZ12, which encode two other core components of PRC2, and predict the presence of pathogenic variants in undiagnosed individuals with OGID. The discovery of a functionally relevant signature with utility for diagnostic classification of sequence variants in EZH2, EED, and SUZ12 supports the emerging paradigm shift for implementation of DNAm signatures into diagnostics and translational research.


Assuntos
Anormalidades Múltiplas/genética , Hipotireoidismo Congênito/genética , Anormalidades Craniofaciais/genética , Metilação de DNA , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Deformidades Congênitas da Mão/genética , Deficiência Intelectual/genética , Mutação , Complexo Repressor Polycomb 2/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Masculino , Mosaicismo , Mutação de Sentido Incorreto/genética , Reprodutibilidade dos Testes , Adulto Jovem
12.
Gene ; 742: 144542, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32184166

RESUMO

Homozygous loss-of-function variants in MYO18B have been associated with congenital myopathy, facial dysmorphism and Klippel-Feil anomaly. So far, only four patients have been reported. Comprehensive description of new cases that help to highlight recurrent features and to further delineate the phenotypic spectrum are still missing. We present the fifth case of MYO18B-associated disease in a newborn male patient. Trio exome sequencing identified the previously unreported homozygous nonsense variant c.6433C>T, p.(Arg2145*) in MYO18B (NM_032608.5). While most phenotypic features of our patient align with previously reported cases, we describe the prenatal features for the first time. Taking the phenotypic description of our patient into account, we propose that the core phenotype comprises a severe congenital myopathy with feeding difficulties in infancy and characteristic dysmorphic features.


Assuntos
Anormalidades Craniofaciais/genética , Síndrome de Klippel-Feil/genética , Hipotonia Muscular/genética , Miosinas/genética , Proteínas Supressoras de Tumor/genética , Idade de Início , Consanguinidade , Anormalidades Craniofaciais/diagnóstico , Análise Mutacional de DNA , Humanos , Lactente , Síndrome de Klippel-Feil/classificação , Síndrome de Klippel-Feil/diagnóstico , Mutação com Perda de Função , Masculino , Hipotonia Muscular/diagnóstico , Linhagem , Sequenciamento Completo do Exoma
13.
Ann Otol Rhinol Laryngol ; 129(7): 653-656, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32028786

RESUMO

OBJECTIVES: Congenital midline cervical cleft (CMCC) is a rare congenital anterior neck anatomical anomaly. We present the case of two related patients (grandchild and maternal grandmother) who were both born with a congenital midline cervical cleft along with genetic analysis. METHODS: Clinical examination of both patients and surgical excision of the grandchild was performed. Genetic analysis with exome sequencing (ES) was conducted for both patients. RESULTS: Genetic analysis with exome sequencing (ES) revealed apparently novel single nucleotide variants in 66 genes present in both proband and grandmother. Five of these variants are predicted to cause frameshifting in the coding region of the respective genes and truncated proteins (OVGP1, TYW1B, ZAN, SSPO, FOLR3). Two of these genes (TYW1B and SSPO) have homozygous indel mutations in both patients. CONCLUSIONS: To our knowledge, this is the first case of two related patients with a congenital midline cervical cleft. The results of our genetic analysis reveal potential relevance to CMCC development.


Assuntos
Região Branquial/anormalidades , Proteínas de Transporte/genética , Moléculas de Adesão Celular Neuronais/genética , Anormalidades Craniofaciais/genética , Glicoproteínas/genética , Pescoço/anormalidades , Doenças Faríngeas/genética , Região Branquial/cirurgia , Anormalidades Craniofaciais/cirurgia , Feminino , Mutação da Fase de Leitura , Avós , Humanos , Mutação INDEL , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Oxigenases de Função Mista/genética , Pescoço/cirurgia , Doenças Faríngeas/cirurgia , Polimorfismo de Nucleotídeo Único , Sequenciamento Completo do Exoma
14.
Ann Otol Rhinol Laryngol ; 129(7): 645-648, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32100546

RESUMO

OBJECTIVES: To discuss the presentation and management of infants with arhinia or congenital absence of the nose. METHODS: This case report describes an infant with arhinia that was diagnosed prenatally. In addition to a discussion of the case, a review of the literature was completed to define appropriate postnatal work-up and management. RESULTS: The patient is a term male infant, diagnosed with arhinia on ultrasound and magnetic resonance imaging (MRI) performed at 21-weeks gestational age. Upon birth, the patient was subsequently intubated, followed by tracheostomy due to complete nasal obstruction. Through a genetics evaluation, the patient was found to be heterozygous for the SMCHD1 gene, with hypomethylation at the D4Z4 locus. Plans for reconstruction will be based on future imaging and the development of any nasal patency, however, the patient's family plans to utilize a prosthetic nose until the patient is older. CONCLUSION: Arhinia is a rare condition causing respiratory distress in the neonatal period. While stabilization of the airway is the first priority, further management is not clearly defined given the rarity of the malformation. This case discusses stabilization of the airway with a review of treatment and reconstructive options.


Assuntos
Anormalidades Craniofaciais/diagnóstico por imagem , Nariz/anormalidades , Manuseio das Vias Aéreas , Proteínas Cromossômicas não Histona/genética , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/terapia , Gerenciamento Clínico , Humanos , Recém-Nascido , Imagem por Ressonância Magnética , Masculino , Mutação de Sentido Incorreto , Nariz/diagnóstico por imagem , Diagnóstico Pré-Natal , Próteses e Implantes , Procedimentos Cirúrgicos Reconstrutivos , Tomografia Computadorizada por Raios X , Traqueostomia , Ultrassonografia Pré-Natal
15.
PLoS Genet ; 16(2): e1008300, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32092051

RESUMO

Craniofrontonasal syndrome (CFNS) is a rare X-linked disorder characterized by craniofacial, skeletal, and neurological anomalies and is caused by mutations in EFNB1. Heterozygous females are more severely affected by CFNS than hemizygous males, a phenomenon called cellular interference that results from EPHRIN-B1 mosaicism. In Efnb1 heterozygous mice, mosaicism for EPHRIN-B1 results in cell sorting and more severe phenotypes than Efnb1 hemizygous males, but how craniofacial dysmorphology arises from cell segregation is unknown and CFNS etiology therefore remains poorly understood. Here, we couple geometric morphometric techniques with temporal and spatial interrogation of embryonic cell segregation in mouse mutant models to elucidate mechanisms underlying CFNS pathogenesis. By generating EPHRIN-B1 mosaicism at different developmental timepoints and in specific cell populations, we find that EPHRIN-B1 regulates cell segregation independently in early neural development and later in craniofacial development, correlating with the emergence of quantitative differences in face shape. Whereas specific craniofacial shape changes are qualitatively similar in Efnb1 heterozygous and hemizygous mutant embryos, heterozygous embryos are quantitatively more severely affected, indicating that Efnb1 mosaicism exacerbates loss of function phenotypes rather than having a neomorphic effect. Notably, neural tissue-specific disruption of Efnb1 does not appear to contribute to CFNS craniofacial dysmorphology, but its disruption within neural crest cell-derived mesenchyme results in phenotypes very similar to widespread loss. EPHRIN-B1 can bind and signal with EPHB1, EPHB2, and EPHB3 receptor tyrosine kinases, but the signaling partner(s) relevant to CFNS are unknown. Geometric morphometric analysis of an allelic series of Ephb1; Ephb2; Ephb3 mutant embryos indicates that EPHB2 and EPHB3 are key receptors mediating Efnb1 hemizygous-like phenotypes, but the complete loss of EPHB1-3 does not fully recapitulate the severity of CFNS-like Efnb1 heterozygosity. Finally, by generating Efnb1+/Δ; Ephb1; Ephb2; Ephb3 quadruple knockout mice, we determine how modulating cumulative receptor activity influences cell segregation in craniofacial development and find that while EPHB2 and EPHB3 play an important role in craniofacial cell segregation, EPHB1 is more important for cell segregation in the brain; surprisingly, complete loss of EPHB1-EPHB3 does not completely abrogate cell segregation. Together, these data advance our understanding of the etiology and signaling interactions underlying CFNS dysmorphology.


Assuntos
Movimento Celular/genética , Anormalidades Craniofaciais/genética , Efrina-B1/genética , Crista Neural/embriologia , Crânio/anormalidades , Animais , Anormalidades Craniofaciais/diagnóstico , Modelos Animais de Doenças , Embrião de Mamíferos , Desenvolvimento Embrionário/genética , Efrina-B1/metabolismo , Feminino , Heterozigoto , Humanos , Masculino , Camundongos , Camundongos Knockout , Mosaicismo , Mutação , Crista Neural/citologia , Fenótipo , Receptores da Família Eph/genética , Receptores da Família Eph/metabolismo , Índice de Gravidade de Doença , Fatores Sexuais , Crânio/embriologia , Cromossomo X/genética
16.
Nat Commun ; 11(1): 480, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980599

RESUMO

Mutations in the actively expressed, maternal allele of the imprinted KCNK9 gene cause Birk-Barel intellectual disability syndrome (BBIDS). Using a BBIDS mouse model, we identify here a partial rescue of the BBIDS-like behavioral and neuronal phenotypes mediated via residual expression from the paternal Kcnk9 (Kcnk9pat) allele. We further demonstrate that the second-generation HDAC inhibitor CI-994 induces enhanced expression from the paternally silenced Kcnk9 allele and leads to a full rescue of the behavioral phenotype suggesting CI-994 as a promising molecule for BBIDS therapy. Thus, these findings suggest a potential approach to improve cognitive dysfunction in a mouse model of an imprinting disorder.


Assuntos
Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/metabolismo , Histonas/metabolismo , Deficiência Intelectual/genética , Deficiência Intelectual/metabolismo , Hipotonia Muscular/genética , Hipotonia Muscular/metabolismo , Canais de Potássio/genética , Animais , Comportamento Animal , Encéfalo/metabolismo , Anormalidades Craniofaciais/tratamento farmacológico , Modelos Animais de Doenças , Feminino , Técnicas de Silenciamento de Genes , Impressão Genômica , Inibidores de Histona Desacetilases/farmacologia , Humanos , Deficiência Intelectual/tratamento farmacológico , Locus Cerúleo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hipotonia Muscular/tratamento farmacológico , Mutação , Fenótipo , Fenilenodiaminas/farmacologia , Canais de Potássio/deficiência , Canais de Potássio/metabolismo , Regulação para Cima/efeitos dos fármacos
17.
Acta Vet Scand ; 62(1): 5, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969185

RESUMO

BACKGROUND: Otocephaly is a rare lethal malformation of the first branchial arch. While the knowledge on the causes of otocephaly in animals is limited, different syndromic forms in man are associated with variants of the PRRX1 and OTX2 genes. CASE PRESENTATION: A stillborn male lamb of the Istrian Pramenka sheep breed showed several congenital craniofacial anomalies including microstomia, agnathia, aglossia, and synotia. In addition, the lamb had a cleft palate, a small opening in the ventral neck region, a cystic oesophagus and two hepatic cysts. The brain was normally developed despite the deformed shape of the head. Taken together the findings led to a diagnosis of otocephaly. Whole-genome sequencing was performed from DNA of the affected lamb and both parents revealing a heterozygous single nucleotide variant in the OTX2 gene (Chr7: 71478714G > A). The variant was absent in both parents and therefore due to a de novo mutation event. It was a nonsense variant, XM_015097088.2:c.265C > T; which leads to an early premature stop codon and is predicted to truncate more than 70% of the OTX2 open reading frame (p.Arg89*). CONCLUSIONS: The genetic findings were consistent with the diagnosis of the otocephaly and provide strong evidence that the identified loss-of-function variant is pathogenic due to OTX2 haploinsufficiency. The benefits of trio-based whole-genome sequencing as an emerging tool in veterinary pathology to confirm diagnosis are highlighted.


Assuntos
Anormalidades Craniofaciais/veterinária , Variação Genética , Mutação , Fatores de Transcrição Otx/genética , Doenças dos Ovinos/genética , Animais , Anormalidades Craniofaciais/genética , Ovinos
18.
J Clin Ultrasound ; 48(4): 240-243, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31994200

RESUMO

We report the case of a fetus with sonographic characteristics of Beckwith-Wiedemann syndrome (BWS). A 30-year-old gravida 2 para 1 was referred to our fetal medicine unit with an omphalocele. Fetal macrosomia, organomegaly, and polyhydramnios but no macroglossia were detected and BWS was suspected. Genetic testing for BWS did not confirm the suspected diagnosis as the karyotype was normal. Symptomatic polyhydramnios led to repeated amnioreductions. At 35 + 5 weeks of gestation, a female neonate of 3660 g was delivered with APGAR scores of 6/7/8, after 1/5/10 min, respectively. The abnormal shape of the thorax, facial dysmorphism, need for ventilation, and generalized muscular hypotonia led to the suspicion of Kagami-Ogata syndrome (KOS), which was confirmed by genetic testing. KOS in our patient was caused by a large deletion in the MEG3-region on chromosome 14q32 affecting the maternal allele. In this report, we highlight the notion that when sonographic signs suggestive of BWS such as macrosomia, polyhydramnios, and omphalocele are present and genetic testing does not confirm the suspected diagnosis, KOS should be tested for.


Assuntos
Síndrome de Beckwith-Wiedemann/diagnóstico por imagem , Transtornos Cromossômicos/diagnóstico por imagem , Anormalidades Craniofaciais/diagnóstico por imagem , Deficiências do Desenvolvimento/diagnóstico por imagem , Hérnia Umbilical/diagnóstico por imagem , Poli-Hidrâmnios/diagnóstico por imagem , Dissomia Uniparental/patologia , Adulto , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 14/genética , Anormalidades Craniofaciais/genética , Deficiências do Desenvolvimento/genética , Diagnóstico Diferencial , Feminino , Idade Gestacional , Hérnia Umbilical/genética , Humanos , Recém-Nascido , Poli-Hidrâmnios/genética , Gravidez , Ultrassonografia Pré-Natal , Dissomia Uniparental/genética
19.
PLoS One ; 15(1): e0220348, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31935221

RESUMO

In a process linked to DNA replication, duplicated chromosomes are entrapped in large, circular cohesin complexes and functional sister chromatid cohesion (SCC) is established by acetylation of the SMC3 cohesin subunit. Roberts Syndrome (RBS) and Warsaw Breakage Syndrome (WABS) are rare human developmental syndromes that are characterized by defective SCC. RBS is caused by mutations in the SMC3 acetyltransferase ESCO2, whereas mutations in the DNA helicase DDX11 lead to WABS. We found that WABS-derived cells predominantly rely on ESCO2, not ESCO1, for residual SCC, growth and survival. Reciprocally, RBS-derived cells depend on DDX11 to maintain low levels of SCC. Synthetic lethality between DDX11 and ESCO2 correlated with a prolonged delay in mitosis, and was rescued by knockdown of the cohesin remover WAPL. Rescue experiments using human or mouse cDNAs revealed that DDX11, ESCO1 and ESCO2 act on different but related aspects of SCC establishment. Furthermore, a DNA binding DDX11 mutant failed to correct SCC in WABS cells and DDX11 deficiency reduced replication fork speed. We propose that DDX11, ESCO1 and ESCO2 control different fractions of cohesin that are spatially and mechanistically separated.


Assuntos
Acetiltransferases/genética , Proteínas de Ciclo Celular/genética , Cromátides/metabolismo , Proteínas Cromossômicas não Histona/genética , RNA Helicases DEAD-box/genética , DNA Helicases/genética , Células Epiteliais/enzimologia , Fibroblastos/enzimologia , Acetiltransferases/metabolismo , Animais , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Linhagem Celular Transformada , Proliferação de Células , Cromátides/ultraestrutura , Proteínas Cromossômicas não Histona/metabolismo , Quebra Cromossômica , Segregação de Cromossomos , Anormalidades Craniofaciais/enzimologia , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/patologia , RNA Helicases DEAD-box/metabolismo , DNA Helicases/metabolismo , Ectromelia/enzimologia , Ectromelia/genética , Ectromelia/patologia , Células Epiteliais/patologia , Fibroblastos/patologia , Expressão Gênica , Humanos , Hipertelorismo/enzimologia , Hipertelorismo/genética , Hipertelorismo/patologia , Camundongos , Mitose , Modelos Biológicos , Mutação , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
20.
BMC Med Genet ; 21(1): 7, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31910817

RESUMO

BACKGROUND: Osteocraniostenosis (OCS) is a rare genetic disorder characterised by premature closure of cranial sutures, gracile bones and perinatal lethality. Previously, diagnosis has only been possible postnatally on clinical and radiological features. This study describes the first prenatal diagnosis of OCS. CASE PRESENTATION: In this case prenatal ultrasound images were suggestive of a serious but non-lethal skeletal dysplasia. Due to the uncertain prognosis the parents were offered Whole Exome Sequencing (WES), which identified a specific gene mutation in the FAMIIIa gene. This mutation had previously been detected in two cases and was lethal in both perinatally. This established the diagnosis, a clear prognosis and allowed informed parental choice regarding ongoing pregnancy management. CONCLUSIONS: This case report supports the use of targeted WES prenatally to confirm the underlying cause and prognosis of sonographically suspected abnormalities.


Assuntos
Doenças do Desenvolvimento Ósseo/diagnóstico , Anormalidades Craniofaciais/diagnóstico , Citocinas/genética , Diagnóstico Pré-Natal , Sequenciamento Completo do Exoma , Adulto , Doenças do Desenvolvimento Ósseo/diagnóstico por imagem , Doenças do Desenvolvimento Ósseo/genética , Doenças do Desenvolvimento Ósseo/patologia , Anormalidades Craniofaciais/diagnóstico por imagem , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/patologia , Feminino , Humanos , Recém-Nascido , Pais , Gravidez
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