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1.
Am J Med Genet A ; 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31509347

RESUMO

Fetal micrognathia can be detected early in pregnancy. Prognosis of micrognathia depends on the risk of respiratory distress at birth and on the long-term risk of intellectual disability. The purpose of this study was to evaluate the long-term prognosis of fetuses with prenatal diagnosis of micrognathia by estimating the prevalence and the severity of confirmed genetic diagnosis in our cohort. Our retrospective study included 41 fetuses with prenatal diagnosis of micrognathia referred to the multidisciplinary centers for prenatal diagnosis in Nice and Marseille, France, between 2006 and 2016. Fetal micrognathia was associated with cleft palate in 27 cases. A genetic cause was confirmed in 21 cases (67%). A chromosomal abnormality was present in 12 cases, including three copy-number variations diagnosed by array CGH. Monogenic disorders were identified in nine cases, most often after birth. Fetuses with family history of micrognathia or Pierre Robin sequence had a favorable outcome. Prognosis was good for the fetuses without associated findings and normal chromosomal analysis, with the exception of one case with a postnatal diagnosis of mandibulofacial dysostosis with microcephaly. Prognostic was poor for the fetuses with additional ultrasound anomalies, as only 5 out of 28 children had a good outcome. Prenatal diagnosis of micrognathia is an indicator of a possible fetal pathology justifying multidisciplinary management. Our study confirms the necessity of performing prenatal array CGH. Use of high-throughput gene sequencing in prenatal period could improve diagnostic performance, prenatal counseling, and adequate postnatal care.

2.
Clin Dysmorphol ; 28(4): 205-210, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31425298

RESUMO

Gonadal mosaicism has been reported in a variety of dominant or X-linked conditions and should be considered in all cases of apparent de-novo variation. Recently, some cases of supposed parental germline mosaicism have been shown to result from low-level somatic mosaicism. In most of the cases, mosaicism has been reported for pathogenic single nucleotide variants with only a few cases of copy number variation mosaicism described so far. Herein, we present the first case of parental somatic and gonadal copy number variation mosaicism in the SATB2 gene. We report three brothers presenting with the SATB2-associated syndrome. They all carry the same 121-kb heterozygous intragenic deletion of SATB2. Parental somatic mosaicism was detected by array-comparative genomic hybridization on a maternal blood sample and confirmed by Fluorescence in situ hybridization analysis on blood and buccal cells. This clinical report highlights the importance of investigating for parental somatic mosaicism to estimate the proper recurrence risk for subsequent pregnancy.

3.
Prenat Diagn ; 39(7): 549-562, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31046133

RESUMO

OBJECTIVE: To evaluate the complementarity between prenatal ultrasound, computed tomography, and MRI scans for fetuses with Binder phenotype. METHODS: We carried out a retrospective study from January 1, 2009, to June 30, 2018, of fetuses with Binder phenotype. Prenatal ultrasound (US) data were collected. A systematic survey of the entire skeleton was performed to look for associated abnormalities such as calcifications, brachytelephalangy, and spinal stenosis. Parents were systematically offered fetal skeletal computed tomography (CT). RESULTS: Thirteen cases were included. Two cases of perinatal respiratory distress (18%) were observed. Chondrodysplasia punctata was diagnosed from the presence of calcifications, especially of the proximal femoral epiphyses and tarsal bones, in five cases (38%) by US and in 10 cases (83%) by CT. Calcifications of the hyoid bone were detected by CT in three cases (25%) one of which had respiratory distress. Polyhydramnios was associated with the Binder phenotype in four cases (30%) one of which had respiratory distress. One single fetus had combined polyhydramnios and laryngeal calcifications, and he suffered from perinatal respiratory distress. CONCLUSION: An antenatal diagnosis of Binder phenotype is often associated with chondrodysplasia punctata. We recommend the use of fetal CT as a complement to US in this condition.

4.
Sci Rep ; 8(1): 9112, 2018 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-29904107

RESUMO

Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare genetic disorder that leads to premature aging. In this study, we used induced pluripotent stem cells to investigate the hypopigmentation phenotypes observed in patients with progeria. Accordingly, two iPS cell lines were derived from cells from HGPS patients and differentiated into melanocytes. Measurements of melanin content revealed a lower synthesis of melanin in HGPS melanocytes as compared to non-pathologic cells. Analysis of the melanosome maturation process by electron microscopy revealed a lower percentage of mature, fully pigmented melanosomes. Finally, a functional rescue experiment revealed the direct role of progerin in the regulation of melanogenesis. Overall, these results report a new dysregulated pathway in HGPS and open up novel perspectives in the study of pigmentation phenotypes that are associated with normal and pathological aging.

5.
J Med Genet ; 55(6): 359-371, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29618507

RESUMO

The Xq28 duplication involving the MECP2 gene (MECP2 duplication) has been mainly described in male patients with severe developmental delay (DD) associated with spasticity, stereotypic movements and recurrent infections. Nevertheless, only a few series have been published. We aimed to better describe the phenotype of this condition, with a focus on morphological and neurological features. Through a national collaborative study, we report a large French series of 59 affected males with interstitial MECP2 duplication. Most of the patients (93%) shared similar facial features, which evolved with age (midface hypoplasia, narrow and prominent nasal bridge, thick lower lip, large prominent ears), thick hair, livedo of the limbs, tapered fingers, small feet and vasomotor troubles. Early hypotonia and global DD were constant, with 21% of patients unable to walk. In patients able to stand, lower limbs weakness and spasticity led to a singular standing habitus: flexion of the knees, broad-based stance with pseudo-ataxic gait. Scoliosis was frequent (53%), such as divergent strabismus (76%) and hypermetropia (54%), stereotypic movements (89%), without obvious social withdrawal and decreased pain sensitivity (78%). Most of the patients did not develop expressive language, 35% saying few words. Epilepsy was frequent (59%), with a mean onset around 7.4 years of age, and often (62%) drug-resistant. Other medical issues were frequent: constipation (78%), and recurrent infections (89%), mainly lung. We delineate the clinical phenotype of MECP2 duplication syndrome in a large series of 59 males. Pulmonary hypertension appeared as a cause of early death in these patients, advocating its screening early in life.

6.
Am J Hum Genet ; 102(3): 364-374, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29429573

RESUMO

Despite the rapid discovery of genes for rare genetic disorders, we continue to encounter individuals presenting with syndromic manifestations. Here, we have studied four affected people in three families presenting with cholestasis, congenital diarrhea, impaired hearing, and bone fragility. Whole-exome sequencing of all affected individuals and their parents identified biallelic mutations in Unc-45 Myosin Chaperone A (UNC45A) as a likely driver for this disorder. Subsequent in vitro and in vivo functional studies of the candidate gene indicated a loss-of-function paradigm, wherein mutations attenuated or abolished protein activity with concomitant defects in gut development and function.

7.
Hum Mutat ; 39(3): 319-332, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29243349

RESUMO

Autosomal recessive microcephaly or microcephaly primary hereditary (MCPH) is a genetically heterogeneous neurodevelopmental disorder characterized by a reduction in brain volume, indirectly measured by an occipitofrontal circumference (OFC) 2 standard deviations or more below the age- and sex-matched mean (-2SD) at birth and -3SD after 6 months, and leading to intellectual disability of variable severity. The abnormal spindle-like microcephaly gene (ASPM), the human ortholog of the Drosophila melanogaster "abnormal spindle" gene (asp), encodes ASPM, a protein localized at the centrosome of apical neuroprogenitor cells and involved in spindle pole positioning during neurogenesis. Loss-of-function mutations in ASPM cause MCPH5, which affects the majority of all MCPH patients worldwide. Here, we report 47 unpublished patients from 39 families carrying 28 new ASPM mutations, and conduct an exhaustive review of the molecular, clinical, neuroradiological, and neuropsychological features of the 282 families previously reported (with 161 distinct ASPM mutations). Furthermore, we show that ASPM-related microcephaly is not systematically associated with intellectual deficiency and discuss the association between the structural brain defects (strong reduction in cortical volume and surface area) that modify the cortical map of these patients and their cognitive abilities.

8.
Am J Med Genet C Semin Med Genet ; 175(4): 417-430, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29178447

RESUMO

CHARGE syndrome (CS) is a genetic disorder whose first description included Coloboma, Heart disease, Atresia of choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies and deafness, most often caused by a genetic mutation in the CHD7 gene. Two features were then added: semicircular canal anomalies and arhinencephaly/olfactory bulb agenesis, with classification of typical, partial, or atypical forms on the basis of major and minor clinical criteria. The detection rate of a pathogenic variant in the CHD7 gene varies from 67% to 90%. To try to have an overview of this heterogenous clinical condition and specify a genotype-phenotype relation, we conducted a national study of phenotype and genotype in 119 patients with CS. Selected clinical diagnostic criteria were from Verloes (2005), updated by Blake & Prasad (). Besides obtaining a detailed clinical description, when possible, patients underwent a full ophthalmologic examination, audiometry, temporal bone CT scan, gonadotropin analysis, and olfactory-bulb MRI. All patients underwent CHD7 sequencing and MLPA analysis. We found a pathogenic CHD7 variant in 83% of typical CS cases and 58% of atypical cases. Pathogenic variants in the CHD7 gene were classified by the expected impact on the protein. In all, 90% of patients had a typical form of CS and 10% an atypical form. The most frequent features were deafness/semicircular canal hypoplasia (94%), pituitary defect/hypogonadism (89%), external ear anomalies (87%), square-shaped face (81%), and arhinencephaly/anosmia (80%). Coloboma (73%), heart defects (65%), and choanal atresia (43%) were less frequent.


Assuntos
Síndrome CHARGE/diagnóstico , Síndrome CHARGE/genética , Estudos de Associação Genética , Genótipo , Fenótipo , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Adolescente , Adulto , Alelos , Substituição de Aminoácidos , Sistema Nervoso Central/anormalidades , Criança , Pré-Escolar , Estudos de Coortes , Nervos Cranianos/anormalidades , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Feminino , França , Testes Genéticos , Humanos , Lactente , Masculino , Técnicas de Diagnóstico Molecular , Adulto Jovem
9.
J Neuropathol Exp Neurol ; 76(3): 195-205, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28395088

RESUMO

Dyneins play a critical role in a wide variety of cellular functions such as the movement of organelles and numerous aspects of mitosis, making it central player in neocortical neurogenesis and migration. Recently, cytoplasmic dynein-1, heavy chain-1 (DYNC1H1) mutations have been found to cause a wide spectrum of brain cortical malformations. We report on the detailed neuropathological features of brain lesions from 2 fetuses aged 36 and 22 weeks of gestation (WG), respectively, carrying de novo DYNC1H1 mutations, p.Arg2720Lys and p.Val3951Ala and presenting the most severe phenotype reported to date. Analysis using the Dictyostelium discoideum dynein motor crystal structure showed that the mutations are both predicted to have deleterious consequences on the function of the motor domain. Both fetuses showed a similar macroscopic and histological brain malformative complex associating bilateral fronto-parietal polymicrogyria (PMG), dysgenesis of the corpus callosum and of the cortico-spinal tracts, along with brainstem and cerebellar abnormalities. Both exhibited extremely severe disrupted cortical lamination. Immunohistochemical studies provided the evidence for defects in cell proliferation and postmitotic neuroblast ability to exit from the subventricular zone resulting in a failure of radial migration toward the cortical plate, thus providing new insights for the understanding of the pathophysiology in these cortical malformations.


Assuntos
Encéfalo/anormalidades , Encéfalo/patologia , Dineínas do Citoplasma/genética , Mutação/genética , Fenótipo , Adulto , Técnicas de Cultura de Células , Feminino , Feto , Humanos , Neuropatologia , Gravidez , Estrutura Secundária de Proteína
10.
Eur J Obstet Gynecol Reprod Biol ; 212: 166-170, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28391132

RESUMO

OBJECTIVE: The aim of this study was to identify antenatal prognostic factors of neonatal outcomes in cases of fetal echogenic bowel (FEB). STUDY DESIGN: A retrospective study in three tertiary referral centers including fetal echogenic bowel over a 10-year period (from January 2003 to December 2013). The echogenicity of the fetal bowel was graded from 1 to 3, according to Slotnick's definition. Associated echographic findings such as bowel dilations, gallbladder abnormalities, calcifications, extra-abdominal abnormalities, intrauterine growth restriction (IUGR) and a decrease in amniotic fluid volume, if present were also recorded. This was followed by the FEB's sonographic evolution. The sonographic evolution was considered favorable if it was stable or decreasing and unfavorable if the echogenicity of the bowel increased or if additional sonographic findings appeared. Neonates had a pediatric examination in the delivery room and upon discharge from the maternity hospital. An outcome was considered good in the case of on-term delivery of a newborn with normal clinical examination and meconium elimination. RESULTS: Complete pregnancy outcome data were available for 409 pregnancies. 338 newborns had uneventful outcomes (82.6%). Antenatal exploration diagnosed 4 cases of aneuploidy (1 case of trisomy 13, 1 case of trisomy 18 and 2 cases of triploidies), 16 cases of congenital infections, 9 cases of cystic fibrosis and 11 cases of bowel abnormalities. After a multivariate analysis, we discovered the sonographic grade of the echogenic bowel was not a prognostic factor of neonatal outcome. The isolated fetal echogenic bowel had a 6.6-fold increase chance of uneventful outcomes (adjusted odd ratio (aOR) 6.6, 95% CI 3-14.4). Notably, favorable sonographic evolution (aOR 8.1, 95% CI 4.1-16) and late gestational age at the time of the diagnosis (aOR 1.17, 95% CI 1.07-1.27) are independent, good prognostic factors of good neonatal outcomes. None of the 180 fetuses with isolated fetal echogenic bowel and favorable sonographic evolution had adverse outcomes. Among these, 4 cases (0.98%) of aneuploïdy, 17 cases (4.2%) of congenital infections and 9 cases (2.2%) of cystic fibroses were also diagnosed. No cases of Down syndrome (DS) were reported. CONCLUSION: Our study shows that the grade should not be considered a prognostic factor of neonatal outcomes. Our data suggests the need to reevaluate the concept of systematic amniocentesis. Sonographic evolution of fetal bowel is an independent, strong prognostic factor for good neonatal outcomes. It also better defines the FEB prognostic.


Assuntos
Intestino Ecogênico/diagnóstico por imagem , Ultrassonografia Pré-Natal , Adulto , Intestino Ecogênico/classificação , Intestino Ecogênico/mortalidade , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Gravidez , Resultado da Gravidez , Estudos Retrospectivos , Fatores de Risco
11.
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
13.
J Med Genet ; 53(11): 743-751, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27317772

RESUMO

BACKGROUND: Heterozygous NSD1 mutations were identified in 60%-90% of patients with Sotos syndrome. Recently, mutations of the SETD2 and DNMT3A genes were identified in patients exhibiting only some Sotos syndrome features. Both NSD1 and SETD2 genes encode epigenetic 'writer' proteins that catalyse methylation of histone 3 lysine 36 (H3K36me). The DNMT3A gene encodes an epigenetic 'reader' protein of the H3K36me chromatin mark. METHODS: We aimed at confirming the implication of DNMT3A and SETD2 mutations in an overgrowth phenotype, through a comprehensive targeted-next generation sequencing (NGS) screening in 210 well-phenotyped index cases with a Sotos-like phenotype and no NSD1 mutation, from a French cohort. RESULTS: Six unreported heterozygous likely pathogenic variants in DNMT3A were identified in seven patients: two nonsense variants and four de novo missense variants. One de novo unreported heterozygous frameshift variant was identified in SETD2 in one patient. All the four DNMT3A missense variants affected DNMT3A functional domains, suggesting a potential deleterious impact. DNMT3A-mutated index cases shared similar clinical features including overgrowth phenotype characterised by postnatal tall stature (≥+2SD), macrocephaly (≥+2SD), overweight or obesity at older age, intellectual deficiency and minor facial features. The phenotype associated with SETD2 mutations remains to be described more precisely. The p.Arg882Cys missense de novo constitutional DNMT3A variant found in two patients is the most frequent DNMT3A somatic mutation in acute leukaemia. CONCLUSIONS: Our results illustrate the power of targeted NGS to identify rare disease-causing variants. These observations provided evidence for a unifying mechanism (disruption of apposition and reading of the epigenetic chromatin mark H3K36me) that causes an overgrowth syndrome phenotype. Further studies are needed in order to assess the role of SETD2 and DNMT3A in intellectual deficiency without overgrowth.

14.
J Inherit Metab Dis ; 39(5): 713-723, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27287710

RESUMO

INTRODUCTION: Alpha-1,3-glucosyltransferase congenital disorder of glycosylation (ALG6-CDG) is a congenital disorder of glycosylation. The original patients were described with hypotonia, developmental disability, epilepsy, and increased bleeding tendency. METHODS: Based on Euroglycan database registration, we approached referring clinicians and collected comprehensive data on 41 patients. RESULTS: We found hypotonia and developmental delay in all ALG6-CDG patients and epilepsy, ataxia, proximal muscle weakness, and, in the majority of cases, failure to thrive. Nine patients developed intractable seizures. Coagulation anomalies were present in <50 % of cases, without spontaneous bleedings. Facial dysmorphism was rare, but seven patients showed missing phalanges and brachydactyly. Cyclic behavioral change, with autistic features and depressive episodes, was one of the most significant complaints. Eleven children died before the age of 4 years due to protein losing enteropathy (PLE), sepsis, or seizures. The oldest patient was a 40 year-old Dutch woman. The most common pathogenic protein alterations were p.A333V and p.I299Del, without any clear genotype-phenotype correlation. DISCUSSION: ALG6-CDG has been now described in 89 patients, making it the second most common type of CDG. It has a recognizable phenotype and a primary neurologic presentation.


Assuntos
Ataxia/patologia , Defeitos Congênitos da Glicosilação/patologia , Epilepsia/patologia , Glucosiltransferases/genética , Deformidades Congênitas dos Membros/patologia , Proteínas de Membrana/genética , Transtornos Mentais/patologia , Debilidade Muscular/patologia , Adolescente , Adulto , Ataxia/genética , Criança , Pré-Escolar , Defeitos Congênitos da Glicosilação/genética , Epilepsia/genética , Feminino , Estudos de Associação Genética/métodos , Glicosilação , Humanos , Lactente , Recém-Nascido , Deformidades Congênitas dos Membros/genética , Masculino , Transtornos Mentais/genética , Hipotonia Muscular/genética , Hipotonia Muscular/patologia , Debilidade Muscular/genética , Fenótipo , Estudos Retrospectivos , Convulsões/genética , Convulsões/patologia , Adulto Jovem
15.
Prenat Diagn ; 36(6): 561-7, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27061523

RESUMO

BACKGROUND: CHARGE syndrome is a multiple congenital anomaly syndrome caused by mutations in CHD7. Diagnostic criteria have been proposed to improve diagnosis in fetuses at clinicopathological survey, but no criteria exist for fetal diagnosis during pregnancy. METHOD: We collected prenatal findings of 12 children with CHARGE syndrome diagnosed in the first 3 months and a CHD7 mutation. We retrieved data on prenatal ultrasound (US) follow-up, fetal supplementary investigations, and results of postnatal evaluation. RESULT: Seven pregnancies were complicated by the identification of isolated or multiple congenital anomalies. CHARGE syndrome was suspected in three fetuses but could not be confirmed despite additional examinations. Retrospectively, several postnatal findings could have been seen if they had been specifically searched. Intrauterine growth restriction, previously proposed as an exclusion criterion, complicated two pregnancies and is thus compatible with the diagnosis. CONCLUSION: Diagnosis of CHARGE syndrome remains difficult during pregnancy. If the diagnosis of CHARGE syndrome is raised in utero, we suggest a careful US examination to identify typical external ears, choanal atresia, or microphthalmia. Fetal brain magnetic resonance imaging can be helpful, but a normal result does not exclude the diagnosis. When CHARGE syndrome is highly suspected, CHD7 molecular analysis must be proposed to confirm the diagnosis. © 2016 John Wiley & Sons, Ltd.


Assuntos
Síndrome CHARGE/diagnóstico por imagem , Ventrículos Cerebrais/anormalidades , Ventrículos Cerebrais/diagnóstico por imagem , Fenda Labial/diagnóstico por imagem , Anormalidades Craniofaciais/diagnóstico por imagem , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Orelha Externa/anormalidades , Orelha Externa/diagnóstico por imagem , Feminino , Retardo do Crescimento Fetal/diagnóstico por imagem , Defeitos dos Septos Cardíacos/diagnóstico por imagem , Humanos , Lactente , Recém-Nascido , Rim , Masculino , Fenótipo , Poli-Hidrâmnios/diagnóstico por imagem , Gravidez , Estudos Retrospectivos , Timo/anormalidades , Timo/diagnóstico por imagem , Ultrassonografia Pré-Natal , Ureter/anormalidades , Ureter/diagnóstico por imagem , Anormalidades Urogenitais/diagnóstico por imagem
16.
PLoS Genet ; 12(3): e1005894, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26967905

RESUMO

Ciliopathies are a group of genetic multi-systemic disorders related to dysfunction of the primary cilium, a sensory organelle present at the cell surface that regulates key signaling pathways during development and tissue homeostasis. In order to identify novel genes whose mutations would cause severe developmental ciliopathies, >500 patients/fetuses were analyzed by a targeted high throughput sequencing approach allowing exome sequencing of >1200 ciliary genes. NEK8/NPHP9 mutations were identified in five cases with severe overlapping phenotypes including renal cystic dysplasia/hypodysplasia, situs inversus, cardiopathy with hypertrophic septum and bile duct paucity. These cases highlight a genotype-phenotype correlation, with missense and nonsense mutations associated with hypodysplasia and enlarged cystic organs, respectively. Functional analyses of NEK8 mutations in patient fibroblasts and mIMCD3 cells showed that these mutations differentially affect ciliogenesis, proliferation/apoptosis/DNA damage response, as well as epithelial morphogenesis. Notably, missense mutations exacerbated some of the defects due to NEK8 loss of function, highlighting their likely gain-of-function effect. We also showed that NEK8 missense and loss-of-function mutations differentially affect the regulation of the main Hippo signaling effector, YAP, as well as the expression of its target genes in patient fibroblasts and renal cells. YAP imbalance was also observed in enlarged spheroids of Nek8-invalidated renal epithelial cells grown in 3D culture, as well as in cystic kidneys of Jck mice. Moreover, co-injection of nek8 MO with WT or mutated NEK8-GFP RNA in zebrafish embryos led to shortened dorsally curved body axis, similar to embryos injected with human YAP RNA. Finally, treatment with Verteporfin, an inhibitor of YAP transcriptional activity, partially rescued the 3D spheroid defects of Nek8-invalidated cells and the abnormalities of NEK8-overexpressing zebrafish embryos. Altogether, our study demonstrates that NEK8 human mutations cause major organ developmental defects due to altered ciliogenesis and cell differentiation/proliferation through deregulation of the Hippo pathway.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Cílios/genética , Fosfoproteínas/genética , Doenças Renais Policísticas/genética , Proteínas Quinases/genética , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/biossíntese , Animais , Diferenciação Celular/genética , Cílios/patologia , Feminino , Estudos de Associação Genética , Humanos , Rim/metabolismo , Rim/patologia , Camundongos , Morfogênese/genética , Mutação , Quinases Relacionadas a NIMA , Fosfoproteínas/antagonistas & inibidores , Fosfoproteínas/biossíntese , Doenças Renais Policísticas/patologia , Porfirinas/administração & dosagem , Transdução de Sinais , Verteporfina , Peixe-Zebra
17.
Am J Med Genet A ; 170A(2): 441-445, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26494162

RESUMO

Our study was designed to analyze prenatal manifestations in patients affected with cardio-facio-cutaneous syndrome (CFCS), in order to define indications of DNA testing in utero. Prenatal features were extracted from a national database and additional data were collected from 16 families contacted through the French association of CFC-Costello syndrome. We collected results of ultrasound scan (USS) biometrics, presence of congenital birth defects, and polyhydramnios. From the database, increased nuchal translucency was present in 13% of pregnancies, polyhydramnios in 52%, macrosomia and/or macrocephaly in 16%. Of the 16 pregnancies, 81% were complicated by abnormal USS findings. Polyhydramnios was reported in 67%. Head circumference, biparietal diameter, and abdominal circumference were above the 90th centile in 72%, 83% and, 81% of fetuses, respectively. Contrasting with macrosomia, femur length was below the 10th centile in 38%. Urinary tract abnormalities were found in 47% of fetuses. Most CFCS fetuses showed a combination of macrocephaly, macrosomia, and polyhydramnios, contrasting with relatively short femora. This growth pattern is also seen in Costello syndrome. We suggest that screening for CFCS and Costello gene mutations could be proposed in pregnancies showing this unusual pattern of growth parameters.


Assuntos
Anormalidades Múltiplas/genética , Face/anormalidades , Cardiopatias Congênitas/diagnóstico , Mutação/genética , Proteínas Proto-Oncogênicas B-raf/genética , Anormalidades da Pele/diagnóstico , Anormalidades Múltiplas/patologia , Feminino , Feto/anormalidades , Feto/metabolismo , Feto/patologia , Cardiopatias Congênitas/genética , Humanos , Recém-Nascido , Masculino , Fenótipo , Gravidez , Prognóstico , Anormalidades da Pele/genética
18.
Eur J Hum Genet ; 24(7): 992-1000, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26626311

RESUMO

Heterozygous COL2A1 variants cause a wide spectrum of skeletal dysplasia termed type II collagenopathies. We assessed the impact of this gene in our French series. A decision tree was applied to select 136 probands (71 Stickler cases, 21 Spondyloepiphyseal dysplasia congenita cases, 11 Kniest dysplasia cases, and 34 other dysplasia cases) before molecular diagnosis by Sanger sequencing. We identified 66 different variants among the 71 positive patients. Among those patients, 18 belonged to multiplex families and 53 were sporadic. Most variants (38/44, 86%) were located in the triple helical domain of the collagen chain and glycine substitutions were mainly observed in severe phenotypes, whereas arginine to cysteine changes were more often encountered in moderate phenotypes. This series of skeletal dysplasia is one of the largest reported so far, adding 44 novel variants (15%) to published data. We have confirmed that about half of our Stickler patients (46%) carried a COL2A1 variant, and that the molecular spectrum was different across the phenotypes. To further address the question of genotype-phenotype correlation, we plan to screen our patients for other candidate genes using a targeted next-generation sequencing approach.


Assuntos
Substituição de Aminoácidos , Artrite/genética , Doenças do Colágeno/genética , Colágeno Tipo II/genética , Doenças do Tecido Conjuntivo/genética , Perda Auditiva Neurossensorial/genética , Osteocondrodisplasias/genética , Fenótipo , Descolamento Retiniano/genética , Artrite/patologia , Doenças do Colágeno/patologia , Colágeno Tipo II/química , Doenças do Tecido Conjuntivo/patologia , Feminino , Perda Auditiva Neurossensorial/patologia , Humanos , Masculino , Osteocondrodisplasias/patologia , Linhagem , Domínios Proteicos , Descolamento Retiniano/patologia
19.
Hum Mutat ; 36(9): 894-902, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26077438

RESUMO

Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder associating macroglossia, abdominal wall defects, visceromegaly, and a high risk of childhood tumor. Molecular anomalies are mostly epigenetic; however, mutations of CDKN1C are implicated in 8% of cases, including both sporadic and familial forms. We aimed to describe the phenotype of BWS patients with CDKN1C mutations and develop a functional test for CDKN1C mutations. For each propositus, we sequenced the three exons and intron-exon boundaries of CDKN1C in patients presenting a BWS phenotype, including abdominal wall defects, without 11p15 methylation defects. We developed a functional test based on flow cytometry. We identified 37 mutations in 38 pedigrees (50 patients and seven fetuses). Analysis of parental samples when available showed that all mutations tested but one was inherited from the mother. The four missense mutations led to a less severe phenotype (lower frequency of exomphalos) than the other 33 mutations. The following four tumors occurred: one neuroblastoma, one ganglioneuroblastoma, one melanoma, and one acute lymphoid leukemia. Cases of BWS caused by CDKN1C mutations are not rare. CDKN1C sequencing should be performed for BWS patients presenting with abdominal wall defects or cleft palate without 11p15 methylation defects or body asymmetry, or in familial cases of BWS.


Assuntos
Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Inibidor de Quinase Dependente de Ciclina p57/genética , Estudos de Associação Genética , Impressão Genômica , Fenótipo , Alelos , Sequência de Aminoácidos , Substituição de Aminoácidos , Inibidor de Quinase Dependente de Ciclina p57/metabolismo , Feminino , Genótipo , Humanos , Masculino , Dados de Sequência Molecular , Mutação , Linhagem , Alinhamento de Sequência
20.
Eur J Hum Genet ; 23(8): 1051-61, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25649378

RESUMO

Premature aging syndromes are rare genetic disorders mimicking clinical and molecular features of aging. A recently identified group of premature aging syndromes is linked to mutation of the LMNA gene encoding lamins A and C, and is associated with nuclear deformation and dysfunction. Hutchinson-Gilford progeria syndrome (HGPS) was the first premature aging syndrome linked to LMNA mutation and its molecular bases have been deeply investigated. It is due to a recurrent de novo mutation leading to aberrant splicing and the production of a truncated and toxic nuclear lamin A precursor (prelamin AΔ50), also called progerin. In this work and based on the literature data, we propose to distinguish two main groups of premature aging laminopathies: (1) HGPS and HGP-like syndromes, which share clinical features due to hampered processing and intranuclear toxic accumulation of prelamin A isoforms; and (2) APS (atypical progeria syndromes), due to dominant or recessive missense mutations affecting lamins A and C. Among HGPS-like patients, several deleted prelamin A transcripts (prelamin AΔ50, AΔ35 and AΔ90) have been described. The purpose of this work was to characterize those transcripts in eight patients affected with HGP-like rare syndromes. When fibroblasts were available, the relationships between the presence and ratios of these transcripts and other parameters were studied, aiming to increase our understanding of genotype-phenotype relationships in HGPS-like patients. Altogether our results evidence that progerin accumulation is the major pathogenetic mechanism responsible for HGP-like syndromes due to mutations near the donor splice site of exon 11.


Assuntos
Senilidade Prematura/genética , Lamina Tipo A/genética , Progéria/genética , Transcrição Genética , Senilidade Prematura/patologia , Feminino , Fibroblastos , Regulação da Expressão Gênica , Humanos , Lamina Tipo A/biossíntese , Masculino , Mutação , Linhagem , Progéria/patologia , Precursores de Proteínas/genética , Sítios de Splice de RNA/genética , Processamento de RNA
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