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1.
Am J Med Genet A ; 179(7): 1304-1309, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31004414

RESUMO

The spectrum of clinical consequences of variants in the Platelet derived growth factor receptor beta (PDGFRB) gene is wide. Missense variants leading to variable loss of signal transduction in vitro have been reported in the idiopathic basal ganglia calcification (IBGC) syndrome Type 4. In contrast, gain-of-function variants have been reported in infantile myofibromatosis, Penttinen syndrome, and Kosaki overgrowth syndrome. Here, we report a patient harboring a novel postzygotic variant in PDGFRB (c.1682_1684del, p.[Arg561_Tyr562delinsHis]) and presenting severe cerebral malformations, intracerebral calcifications, and infantile myofibromatosis. This observation expands the phenotype associated with PDGFRB variants and illustrates the wide clinical spectrum linked to dysregulation of PDGFRB.

2.
Am J Hum Genet ; 104(3): 530-541, 2019 Mar 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.

4.
Nucleic Acids Res ; 47(6): 2822-2839, 2019 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-30698748

RESUMO

The DNA methylation epigenetic signature is a key determinant during development. Rules governing its establishment and maintenance remain elusive especially at repetitive sequences, which account for the majority of methylated CGs. DNA methylation is altered in a number of diseases including those linked to mutations in factors that modify chromatin. Among them, SMCHD1 (Structural Maintenance of Chromosomes Hinge Domain Containing 1) has been of major interest following identification of germline mutations in Facio-Scapulo-Humeral Dystrophy (FSHD) and in an unrelated developmental disorder, Bosma Arhinia Microphthalmia Syndrome (BAMS). By investigating why germline SMCHD1 mutations lead to these two different diseases, we uncovered a role for this factor in de novo methylation at the pluripotent stage. SMCHD1 is required for the dynamic methylation of the D4Z4 macrosatellite upon reprogramming but seems dispensable for methylation maintenance. We find that FSHD and BAMS patient's cells carrying SMCHD1 mutations are both permissive for DUX4 expression, a transcription factor whose regulation has been proposed as the main trigger for FSHD. These findings open new questions as to what is the true aetiology for FSHD, the epigenetic events associated with the disease thus calling the current model into question and opening new perspectives for understanding repetitive DNA sequences regulation.


Assuntos
Proteínas Cromossômicas não Histona/fisiologia , Metilação de DNA , Proteínas de Homeodomínio/genética , Repetições de Microssatélites/genética , Células Cultivadas , Reprogramação Celular/genética , Atresia das Cóanas/genética , Atresia das Cóanas/metabolismo , Metilação de DNA/genética , Epigênese Genética/genética , Regulação da Expressão Gênica , Células HCT116 , Células HEK293 , Proteínas de Homeodomínio/metabolismo , Humanos , Masculino , Microftalmia/genética , Microftalmia/metabolismo , Distrofia Muscular Facioescapuloumeral/genética , Distrofia Muscular Facioescapuloumeral/metabolismo , Distrofia Muscular Facioescapuloumeral/patologia , Nariz/anormalidades
5.
Am J Hum Genet ; 104(1): 139-156, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30595372

RESUMO

Type 2A protein phosphatases (PP2As) are highly expressed in the brain and regulate neuronal signaling by catalyzing phospho-Ser/Thr dephosphorylations in diverse substrates. PP2A holoenzymes comprise catalytic C-, scaffolding A-, and regulatory B-type subunits, which determine substrate specificity and physiological function. Interestingly, de novo mutations in genes encoding A- and B-type subunits have recently been implicated in intellectual disability (ID) and developmental delay (DD). We now report 16 individuals with mild to profound ID and DD and a de novo mutation in PPP2CA, encoding the catalytic Cα subunit. Other frequently observed features were severe language delay (71%), hypotonia (69%), epilepsy (63%), and brain abnormalities such as ventriculomegaly and a small corpus callosum (67%). Behavioral problems, including autism spectrum disorders, were reported in 47% of individuals, and three individuals had a congenital heart defect. PPP2CA de novo mutations included a partial gene deletion, a frameshift, three nonsense mutations, a single amino acid duplication, a recurrent mutation, and eight non-recurrent missense mutations. Functional studies showed complete PP2A dysfunction in four individuals with seemingly milder ID, hinting at haploinsufficiency. Ten other individuals showed mutation-specific biochemical distortions, including poor expression, altered binding to the A subunit and specific B-type subunits, and impaired phosphatase activity and C-terminal methylation. Four were suspected to have a dominant-negative mechanism, which correlated with severe ID. Two missense variants affecting the same residue largely behaved as wild-type in our functional assays. Overall, we found that pathogenic PPP2CA variants impair PP2A-B56(δ) functionality, suggesting that PP2A-related neurodevelopmental disorders constitute functionally converging ID syndromes.


Assuntos
Deficiência Intelectual/genética , Mutação , Proteína Fosfatase 2/genética , Adolescente , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Células HEK293 , Haploinsuficiência/genética , Humanos , Masculino , Ligação Proteica/genética , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Síndrome
6.
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
7.
Nat Commun ; 9(1): 3087, 2018 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-30082715

RESUMO

Skeletal dysplasia with multiple dislocations are severe disorders characterized by dislocations of large joints and short stature. The majority of them have been linked to pathogenic variants in genes encoding glycosyltransferases, sulfotransferases or epimerases required for glycosaminoglycan synthesis. Using exome sequencing, we identify homozygous mutations in SLC10A7 in six individuals with skeletal dysplasia with multiple dislocations and amelogenesis imperfecta. SLC10A7 encodes a 10-transmembrane-domain transporter located at the plasma membrane. Functional studies in vitro demonstrate that SLC10A7 mutations reduce SLC10A7 protein expression. We generate a Slc10a7-/- mouse model, which displays shortened long bones, growth plate disorganization and tooth enamel anomalies, recapitulating the human phenotype. Furthermore, we identify decreased heparan sulfate levels in Slc10a7-/- mouse cartilage and patient fibroblasts. Finally, we find an abnormal N-glycoprotein electrophoretic profile in patient blood samples. Together, our findings support the involvement of SLC10A7 in glycosaminoglycan synthesis and specifically in skeletal development.

8.
J Clin Endocrinol Metab ; 103(11): 4023-4032, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30137364

RESUMO

Context: Most cases of autosomal dominant isolated hypoparathyroidism are caused by gain-of-function mutations in CASR or GNA11 or dominant negative mutations in GCM2 or PTH. Objective: To identify the genetic etiology for dominantly transmitted isolated hypoparathyroidism in two multigenerational families with 14 affected family members. Methods: We performed whole exome sequencing of DNA from two families and examined the consequences of mutations by minigene splicing assay. Results: We discovered disease-causing mutations in both families. A splice-altering mutation in TBX1 (c.1009+1G>C) leading to skipping of exon 8 (101 bp) was identified in 10 affected family members and five unaffected subjects of family A, indicating reduced penetrance for this point mutation. In a second family from France (family B), we identified another splice-altering mutation (c.1009+2T>C) adjacent to the mutation identified in family A that results in skipping of the same exon; two subjects in family B had isolated hypoparathyroidism, whereas a third subject manifested the clinical triad of the 22q11.2 deletion syndrome, indicative of variable expressivity. Conclusions: We report evidence that heterozygous TBX1 mutations can cause isolated hypoparathyroidism. This study adds knowledge to the increasingly expanding list of causative and candidate genes in isolated hypoparathyroidism.

9.
Am J Med Genet A ; 176(5): 1091-1098, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29681083

RESUMO

Corpus callosum (CC) is the major brain commissure connecting homologous areas of cerebral hemispheres. CC anomalies (CCAs) are the most frequent brain anomalies leading to variable neurodevelopmental outcomes making genetic counseling difficult in the absence of a known etiology that might inform the prognosis. Here, we used whole exome sequencing, and a targeted capture panel of syndromic CCA known causal and candidate genes to screen a cohort of 64 fetuses with CCA observed upon autopsy, and 34 children with CCA and intellectual disability. In one fetus and two patients, we identified three novel de novo mutations in ZBTB20, which was previously shown to be causal in Primrose syndrome. In addition to CCA, all cases presented with additional features of Primrose syndrome including facial dysmorphism and macrocephaly or megalencephaly. All three variations occurred within two out of the five zinc finger domains of the transcriptional repressor ZBTB20. Through homology modeling, these variants are predicted to result in local destabilization of each zinc finger domain suggesting subsequent abnormal repression of ZBTB20 target genes. Neurohistopathological analysis of the fetal case showed abnormal regionalization of the hippocampal formation as well as a reduced density of cortical upper layers where originate most callosal projections. Here, we report novel de novo ZBTB20 mutations in three independent cases with characteristic features of Primrose syndrome including constant CCA. Neurohistopathological findings in fetal case corroborate the observed key role of ZBTB20 during hippocampal and neocortical development. Finally, this study highlights the crucial role of ZBTB20 in CC development in human.

10.
Clin Dysmorphol ; 27(2): 31-35, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29381487

RESUMO

Mandibulofacial dysostosis type Guion-Almeida (MFDGA) is a rare disease entity that results in congenital craniofacial anomalies that are caused by abnormal development of the first and second pharyngeal arches. MFDGA is characterized by malar and mandibular hypoplasia, microcephaly, developmental delay, dysplastic ears, and a distinctive facial appearance. Extracraniofacial malformations include esophageal atresia, congenital heart disease, and radial ray abnormalities. Heterozygous mutations in the elongation factor Tu GTP-binding domain containing 2 (EFTUD2) gene have been shown to result in MFDGA. To date, there have been a total of 108 individuals reported in the literature, of whom 95 patients have a confirmed EFTUD2 mutation. The majority of individuals reported in the literature have been of White ethnic origin. Here, we report two individuals of Asian ancestry with MFDGA, each harboring a novel, pathogenic splice site variant in EFTUD2.


Assuntos
Deficiências do Desenvolvimento/genética , Disostose Mandibulofacial/genética , Fatores de Alongamento de Peptídeos/genética , Ribonucleoproteína Nuclear Pequena U5/genética , Pré-Escolar , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Heterozigoto , Humanos , Lactente , Masculino , Disostose Mandibulofacial/fisiopatologia , Mutação , Isoformas de Proteínas/genética
11.
Eur J Hum Genet ; 26(3): 340-349, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29330547

RESUMO

Fryns syndrome (FS) is a multiple malformations syndrome with major features of congenital diaphragmatic hernia, pulmonary hypoplasia, craniofacial dysmorphic features, distal digit hypoplasia, and a range of other lower frequency malformations. FS is typically lethal in the fetal or neonatal period. Inheritance is presumed autosomal recessive. Although no major genetic cause has been identified for FS, biallelic truncating variants in PIGN, encoding a component of the glycosylphosphatidylinositol (GPI)-anchor biosynthesis pathway, have been identified in a limited number of cases with a phenotype compatible with FS. Biallelic variants in PIGN, typically missense or compound missense with truncating, also cause multiple congenital anomalies-hypotonia-seizures syndrome 1 (MCAHS1). Here we report six further patients with FS with or without congenital diaphragmatic hernia and recessive loss of function PIGN alleles, including an intragenic deletion with a likely founder effect in La Réunion and other Indian Ocean islands. Our results support the hypothesis that a spectrum of phenotypic severity is associated with recessive PIGN variants, ranging from FS at the extreme end, caused by complete loss of function, to MCAHS1, in which some residual PIGN function may remain. Our data add FS resulting from PIGN variants to the catalog of inherited GPI deficiencies caused by the disruption of the GPI-anchor biosynthesis pathway.

12.
Am J Med Genet A ; 176(1): 181-186, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29159987

RESUMO

We report two unrelated patients with Pierre Robin sequence (PRS) and a strikingly similar combination of associated features. Whole exome sequencing was performed for both patients. No single gene containing likely pathogenic point mutations in both patients could be identified, but the finding of an essential splice site mutation in mediator complex subunit 13 like (MED13L) in one patient prompted the investigation of copy number variants in MED13L in the other, leading to the identification of an intragenic deletion. Disruption of MED13L, encoding a component of the Mediator complex, is increasingly recognized as the cause of an intellectual disability syndrome with associated facial dysmorphism. Our findings suggest that MED13L-related disorders are a possible differential diagnosis for syndromic PRS.


Assuntos
Mutação com Perda de Função , Complexo Mediador/genética , Síndrome de Pierre Robin/diagnóstico , Síndrome de Pierre Robin/genética , Encéfalo/anormalidades , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Humanos , Lactente , Imagem por Ressonância Magnética/métodos , Masculino , Fenótipo , Análise de Sequência de DNA
13.
Am J Hum Genet ; 101(6): 995-1005, 2017 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-29198722

RESUMO

A recurrent de novo missense variant within the C-terminal Sin3-like domain of ZSWIM6 was previously reported to cause acromelic frontonasal dysostosis (AFND), an autosomal-dominant severe frontonasal and limb malformation syndrome, associated with neurocognitive and motor delay, via a proposed gain-of-function effect. We present detailed phenotypic information on seven unrelated individuals with a recurrent de novo nonsense variant (c.2737C>T [p.Arg913Ter]) in the penultimate exon of ZSWIM6 who have severe-profound intellectual disability and additional central and peripheral nervous system symptoms but an absence of frontonasal or limb malformations. We show that the c.2737C>T variant does not trigger nonsense-mediated decay of the ZSWIM6 mRNA in affected individual-derived cells. This finding supports the existence of a truncated ZSWIM6 protein lacking the Sin3-like domain, which could have a dominant-negative effect. This study builds support for a key role for ZSWIM6 in neuronal development and function, in addition to its putative roles in limb and craniofacial development, and provides a striking example of different variants in the same gene leading to distinct phenotypes.


Assuntos
Proteínas de Ligação a DNA/genética , Deficiência Intelectual/genética , Transtornos Neurocognitivos/genética , Sistema Nervoso Central/anormalidades , Sistema Nervoso Central/embriologia , Códon sem Sentido/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Deformidades Congênitas dos Membros/genética , Disostose Mandibulofacial/genética , Sistema Nervoso Periférico/anormalidades , Sistema Nervoso Periférico/enzimologia
14.
Prenat Diagn ; 37(11): 1169-1175, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28950416

RESUMO

OBJECTIVES: To analyze the efficiency of prenatal diagnosis of Pierre Robin sequence (PRS) regarding the final specific diagnosis and to determine whether infants have more severe respiratory disorders with than without prenatally suspected PRS. METHODS: Review of the outcome of all prenatal cases of suspected PRS managed in our prenatal diagnosis center during the last 15 years; analysis of the consistency between prenatal and postnatal diagnoses in 2 groups of women with and without a family history of PRS; comparison of the grades of disease severity for infants with and without prenatally suspected PRS. RESULTS: Fifty-nine files were studied. Prenatal and postnatal consistencies of a specific diagnosis of PRS were 100% for women with a family history of PRS and with prenatally suspected nonisolated PRS. It was 78.6% for those with prenatally suspected isolated PRS. We describe 13 terminations of pregnancy. The 41 children living beyond 18 months seem to have more functionally severe phenotypes than the 227 children without prenatally suspected PRS. CONCLUSION: Prenatal diagnosis of isolated PRS is a challenge as other features can be missed. Use of prenatal chromosomal microarray can improve the accuracy of diagnosis. In all cases, adequate neonatal care should be offered.


Assuntos
Síndrome de Pierre Robin/diagnóstico por imagem , Estudos de Coortes , Feminino , Humanos , Gravidez , Ultrassonografia Pré-Natal
15.
Am J Med Genet A ; 173(4): 938-945, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28328130

RESUMO

Auriculocondylar syndrome, mainly characterized by micrognathia, small mandibular condyle, and question mark ears, is a rare disease segregating in an autosomal dominant pattern in the majority of the families reported in the literature. So far, pathogenic variants in PLCB4, GNAI3, and EDN1 have been associated with this syndrome. It is caused by a developmental abnormality of the first and second pharyngeal arches and it is associated with great inter- and intra-familial clinical variability, with some patients not presenting the typical phenotype of the syndrome. Moreover, only a few patients of each molecular subtype of Auriculocondylar syndrome have been reported and sequenced. Therefore, the spectrum of clinical and genetic variability is still not defined. In order to address these questions, we searched for alterations in PLCB4, GNAI3, and EDN1 in patients with typical Auriculocondylar syndrome (n = 3), Pierre Robin sequence-plus (n = 3), micrognathia with additional craniofacial malformations (n = 4), or non-specific auricular dysplasia (n = 1), which could represent subtypes of Auriculocondylar syndrome. We found novel pathogenic variants in PLCB4 only in two of three index patients with typical Auriculocondylar syndrome. We also performed a detailed comparative analysis of the patients presented in this study with those previously published, which showed that the pattern of auricular abnormality and full cheeks were associated with molecularly characterized individuals with Auriculocondylar syndrome. Finally, our data contribute to a better definition of a set of parameters for clinical classification that may be used as a guidance for geneticists ordering molecular testing for Auriculocondylar syndrome. © 2017 Wiley Periodicals, Inc.


Assuntos
Otopatias/diagnóstico , Orelha/anormalidades , Predisposição Genética para Doença , Micrognatismo/diagnóstico , Mutação , Fosfolipase C beta/genética , Síndrome de Pierre Robin/diagnóstico , Adulto , Criança , Orelha/patologia , Otopatias/classificação , Otopatias/genética , Otopatias/patologia , Endotelina-1/genética , Feminino , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Expressão Gênica , Genes Dominantes , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Micrognatismo/classificação , Micrognatismo/genética , Micrognatismo/patologia , Linhagem , Fenótipo , Síndrome de Pierre Robin/classificação , Síndrome de Pierre Robin/genética , Síndrome de Pierre Robin/patologia , Terminologia como Assunto
16.
Am J Hum Genet ; 100(4): 592-604, 2017 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-28285769

RESUMO

Pre-mRNA splicing factors play a fundamental role in regulating transcript diversity both temporally and spatially. Genetic defects in several spliceosome components have been linked to a set of non-overlapping spliceosomopathy phenotypes in humans, among which skeletal developmental defects and non-syndromic retinitis pigmentosa (RP) are frequent findings. Here we report that defects in spliceosome-associated protein CWC27 are associated with a spectrum of disease phenotypes ranging from isolated RP to severe syndromic forms. By whole-exome sequencing, recessive protein-truncating mutations in CWC27 were found in seven unrelated families that show a range of clinical phenotypes, including retinal degeneration, brachydactyly, craniofacial abnormalities, short stature, and neurological defects. Remarkably, variable expressivity of the human phenotype can be recapitulated in Cwc27 mutant mouse models, with significant embryonic lethality and severe phenotypes in the complete knockout mice while mice with a partial loss-of-function allele mimic the isolated retinal degeneration phenotype. Our study describes a retinal dystrophy-related phenotype spectrum as well as its genetic etiology and highlights the complexity of the spliceosomal gene network.


Assuntos
Anormalidades Múltiplas/genética , Ciclofilinas/genética , Mutação , Peptidilprolil Isomerase/genética , Degeneração Retiniana/genética , Adolescente , Animais , Criança , Pré-Escolar , Ciclofilinas/metabolismo , Feminino , Humanos , Masculino , Camundongos , Linhagem , Peptidilprolil Isomerase/metabolismo , Adulto Jovem
17.
Nat Genet ; 49(2): 249-255, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28067911

RESUMO

Bosma arhinia microphthalmia syndrome (BAMS) is an extremely rare and striking condition characterized by complete absence of the nose with or without ocular defects. We report here that missense mutations in the epigenetic regulator SMCHD1 mapping to the extended ATPase domain of the encoded protein cause BAMS in all 14 cases studied. All mutations were de novo where parental DNA was available. Biochemical tests and in vivo assays in Xenopus laevis embryos suggest that these mutations may behave as gain-of-function alleles. This finding is in contrast to the loss-of-function mutations in SMCHD1 that have been associated with facioscapulohumeral muscular dystrophy (FSHD) type 2. Our results establish SMCHD1 as a key player in nasal development and provide biochemical insight into its enzymatic function that may be exploited for development of therapeutics for FSHD.


Assuntos
Atresia das Cóanas/genética , Proteínas Cromossômicas não Histona/genética , Microftalmia/genética , Mutação de Sentido Incorreto/genética , Nariz/anormalidades , Animais , Linhagem Celular , Pré-Escolar , Epigênese Genética/genética , Feminino , Predisposição Genética para Doença/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Distrofia Muscular Facioescapuloumeral/genética , Xenopus laevis/genética
18.
J Steroid Biochem Mol Biol ; 170: 28-38, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27989796

RESUMO

Human mutations in the SOX9 gene or its regulatory region can disrupt testicular development, leading to disorders of sex development (DSDs). Our previous work involving the genomic analysis of isolated DSD patients revealed a 78kb minimal sex determining region (RevSex) far upstream of SOX9 that was duplicated in 46,XX and deleted in 46,XY DSDs. It was postulated that RevSex contains a gonadal enhancer. However, the most highly conserved sub-region within RevSex, called SR4, was neither responsive to sex determining factors in vitro nor active in the gonads of transgenic mice, suggesting that SR4 may not be functioning as a testicular enhancer. Interestingly, SR4 transgenic mice showed reporter activity in the genital tubercle, the primordium of the penis and clitoris, a previously unreported domain of Sox9 expression. SOX9 protein was detected in the genital tubercle, notably in the urethral plate epithelium, preputial glands, ventral surface ectoderm and corpus cavernosa. SR4 may therefore function as a Sox9 genital tubercle enhancer, mutations of which could possibly lead to hypospadias, a birth defect seen in the DSD patients in the RevSex study. SR4 activity and the observed SOX9 expression pattern suggest that SR4 may function as a Sox9 genital tubercle enhancer. However, conditional ablation of Sox9 in the genital tubercle using Shh-Cre/+;Sox9flox/flox mice revealed no genital tubercle abnormalities, possibly due to compensation by similar Sox factors. To conclude, we have identified a novel regulatory enhancer driving Sox9 expression during external genitalia development.


Assuntos
Genitália Feminina , Hipospadia/genética , Sequências Reguladoras de Ácido Nucleico/genética , Fatores de Transcrição SOX9/genética , Animais , Linhagem Celular , Feminino , Genótipo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Mutação
19.
Am J Hum Genet ; 99(3): 711-719, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27545680

RESUMO

The overall understanding of the molecular etiologies of intellectual disability (ID) and developmental delay (DD) is increasing as next-generation sequencing technologies identify genetic variants in individuals with such disorders. However, detailed analyses conclusively confirming these variants, as well as the underlying molecular mechanisms explaining the diseases, are often lacking. Here, we report on an ID syndrome caused by de novo heterozygous loss-of-function (LoF) mutations in SON. The syndrome is characterized by ID and/or DD, malformations of the cerebral cortex, epilepsy, vision problems, musculoskeletal abnormalities, and congenital malformations. Knockdown of son in zebrafish resulted in severe malformation of the spine, brain, and eyes. Importantly, analyses of RNA from affected individuals revealed that genes critical for neuronal migration and cortex organization (TUBG1, FLNA, PNKP, WDR62, PSMD3, and HDAC6) and metabolism (PCK2, PFKL, IDH2, ACY1, and ADA) are significantly downregulated because of the accumulation of mis-spliced transcripts resulting from erroneous SON-mediated RNA splicing. Our data highlight SON as a master regulator governing neurodevelopment and demonstrate the importance of SON-mediated RNA splicing in human development.


Assuntos
Encéfalo/embriologia , Encéfalo/metabolismo , Proteínas de Ligação a DNA/genética , Genes Essenciais/genética , Deficiência Intelectual/genética , Antígenos de Histocompatibilidade Menor/genética , Mutação/genética , Processamento de RNA/genética , Animais , Encéfalo/anormalidades , Encéfalo/patologia , Proteínas de Ligação a DNA/análise , Proteínas de Ligação a DNA/metabolismo , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/patologia , Deficiências do Desenvolvimento/fisiopatologia , Anormalidades do Olho/genética , Feminino , Haploinsuficiência/genética , Cabeça/anormalidades , Heterozigoto , Humanos , Deficiência Intelectual/patologia , Deficiência Intelectual/fisiopatologia , Masculino , Doenças Metabólicas/genética , Doenças Metabólicas/metabolismo , Antígenos de Histocompatibilidade Menor/análise , Antígenos de Histocompatibilidade Menor/metabolismo , Linhagem , RNA Mensageiro/análise , Coluna Vertebral/anormalidades , Síndrome , Peixe-Zebra/anormalidades , Peixe-Zebra/embriologia , Peixe-Zebra/genética
20.
Am J Hum Genet ; 99(3): 666-673, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27523598

RESUMO

Sudden unexpected death in infancy occurs in apparently healthy infants and remains largely unexplained despite thorough investigation. The vast majority of cases are sporadic. Here we report seven individuals from three families affected by sudden and unexpected cardiac arrest between 4 and 20 months of age. Whole-exome sequencing revealed compound heterozygous missense mutations in PPA2 in affected infants of each family. PPA2 encodes the mitochondrial pyrophosphatase, which hydrolyzes inorganic pyrophosphate into two phosphates. This is an essential activity for many biosynthetic reactions and for energy metabolism of the cell. We show that deletion of the orthologous gene in yeast (ppa2Δ) compromises cell viability due to the loss of mitochondria. Expression of wild-type human PPA2, but not PPA2 containing the mutations identified in affected individuals, preserves mitochondrial function in ppa2Δ yeast. Using a regulatable (doxycycline-repressible) gene expression system, we found that the pathogenic PPA2 mutations rapidly inactivate the mitochondrial energy transducing system and prevent the maintenance of a sufficient electrical potential across the inner membrane, which explains the subsequent disappearance of mitochondria from the mutant yeast cells. Altogether these data demonstrate that PPA2 is an essential gene in yeast and that biallelic mutations in PPA2 cause a mitochondrial disease leading to sudden cardiac arrest in infants.


Assuntos
Alelos , Morte Súbita Cardíaca/etiologia , Pirofosfatase Inorgânica/genética , Proteínas Mitocondriais/genética , Mutação/genética , Morte Súbita Cardíaca/patologia , Difosfatos , Exoma/genética , Feminino , Deleção de Genes , Genes Essenciais/genética , Teste de Complementação Genética , Heterozigoto , Humanos , Lactente , Pirofosfatase Inorgânica/metabolismo , Masculino , Potencial da Membrana Mitocondrial/genética , Viabilidade Microbiana , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/metabolismo , Mutação de Sentido Incorreto , Bombas de Próton/deficiência , Bombas de Próton/genética , Bombas de Próton/metabolismo , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
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