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1.
Am J Hum Genet ; 109(2): 345-360, 2022 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-35045343

RESUMEN

Free oligosaccharides (fOSs) are soluble oligosaccharide species generated during N-glycosylation of proteins. Although little is known about fOS metabolism, the recent identification of NGLY1 deficiency, a congenital disorder of deglycosylation (CDDG) caused by loss of function of an enzyme involved in fOS metabolism, has elicited increased interest in fOS processing. The catabolism of fOSs has been linked to the activity of a specific cytosolic mannosidase, MAN2C1, which cleaves α1,2-, α1,3-, and α1,6-mannose residues. In this study, we report the clinical, biochemical, and molecular features of six individuals, including two fetuses, with bi-allelic pathogenic variants in MAN2C1; the individuals are from four different families. These individuals exhibit dysmorphic facial features, congenital anomalies such as tongue hamartoma, variable degrees of intellectual disability, and brain anomalies including polymicrogyria, interhemispheric cysts, hypothalamic hamartoma, callosal anomalies, and hypoplasia of brainstem and cerebellar vermis. Complementation experiments with isogenic MAN2C1-KO HAP1 cells confirm the pathogenicity of three of the identified MAN2C1 variants. We further demonstrate that MAN2C1 variants lead to accumulation and delay in the processing of fOSs in proband-derived cells. These results emphasize the involvement of MAN2C1 in human neurodevelopmental disease and the importance of fOS catabolism.


Asunto(s)
Quistes del Sistema Nervioso Central/genética , Trastornos Congénitos de Glicosilación/genética , Hamartoma/genética , Discapacidad Intelectual/genética , Oligosacáridos/metabolismo , Péptido-N4-(N-acetil-beta-glucosaminil) Asparagina Amidasa/deficiencia , Polimicrogiria/genética , alfa-Manosidasa/genética , Adolescente , Alelos , Tronco Encefálico/metabolismo , Tronco Encefálico/patología , Línea Celular Tumoral , Quistes del Sistema Nervioso Central/metabolismo , Quistes del Sistema Nervioso Central/patología , Vermis Cerebeloso/metabolismo , Vermis Cerebeloso/patología , Niño , Preescolar , Trastornos Congénitos de Glicosilación/metabolismo , Trastornos Congénitos de Glicosilación/patología , Femenino , Feto , Glicosilación , Hamartoma/metabolismo , Hamartoma/patología , Humanos , Hipotálamo/metabolismo , Hipotálamo/patología , Discapacidad Intelectual/metabolismo , Discapacidad Intelectual/patología , Leucocitos/metabolismo , Leucocitos/patología , Masculino , Manosa/metabolismo , Péptido-N4-(N-acetil-beta-glucosaminil) Asparagina Amidasa/genética , Péptido-N4-(N-acetil-beta-glucosaminil) Asparagina Amidasa/metabolismo , Polimicrogiria/metabolismo , Polimicrogiria/patología , Lengua/metabolismo , Lengua/patología , alfa-Manosidasa/deficiencia
2.
J Med Genet ; 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38849204

RESUMEN

INTRODUCTION: Tonne-Kalscheuer syndrome (TOKAS) is a recessive X-linked multiple congenital anomaly disorder caused by RLIM variations. Of the 41 patients reported, only 7 antenatal cases were described. METHOD: After the antenatal diagnosis of TOKAS by exome analysis in a family followed for over 35 years because of multiple congenital anomalies in five male fetuses, a call for collaboration was made, resulting in a cohort of 11 previously unpublished cases. RESULTS: We present a TOKAS antenatal cohort, describing 11 new cases in 6 French families. We report a high frequency of diaphragmatic hernia (9 of 11), differences in sex development (10 of 11) and various visceral malformations. We report some recurrent dysmorphic features, but also pontocerebellar hypoplasia, pre-auricular skin tags and olfactory bulb abnormalities previously unreported in the literature. Although no clear genotype-phenotype correlation has yet emerged, we show that a recurrent p.(Arg611Cys) variant accounts for 66% of fetal TOKAS cases. We also report two new likely pathogenic variants in RLIM, outside of the two previously known mutational hotspots. CONCLUSION: Overall, we present the first fetal cohort of TOKAS, describe the clinical features that made it a recognisable syndrome at fetopathological examination, and extend the phenotypical spectrum and the known genotype of this rare disorder.

3.
J Med Genet ; 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38937076

RESUMEN

BACKGROUND: Tatton-Brown-Rahman syndrome (TBRS; OMIM 615879), also known as DNA methyltransferase 3 alpha (DNMT3A)-overgrowth syndrome (DOS), was first described by Tatton-Brown in 2014. This syndrome is characterised by overgrowth, intellectual disability and distinctive facial features and is the consequence of germline loss-of-function variants in DNMT3A, which encodes a DNA methyltransferase involved in epigenetic regulation. Somatic variants of DNMT3A are frequently observed in haematological malignancies, including acute myeloid leukaemia (AML). To date, 100 individuals with TBRS with de novo germline variants have been described. We aimed to further characterise this disorder clinically and at the molecular level in a nationwide series of 24 French patients and to investigate the correlation between the severity of intellectual disability and the type of variant. METHODS: We collected genetic and medical information from 24 individuals with TBRS using a questionnaire released through the French National AnDDI-Rares Network. RESULTS: Here, we describe the first nationwide French cohort of 24 individuals with germline likely pathogenic/pathogenic variants in DNMT3A, including 17 novel variants. We confirmed that the main phenotypic features were intellectual disability (100% of individuals), distinctive facial features (96%) and overgrowth (87%). We highlighted novel clinical features, such as hypertrichosis, and further described the neurological features and EEG results. CONCLUSION: This study of a nationwide cohort of individuals with TBRS confirms previously published data and provides additional information and clarifies clinical features to facilitate diagnosis and improve care. This study adds value to the growing body of knowledge on TBRS and broadens its clinical and molecular spectrum.

4.
Genet Med ; 26(7): 101126, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38529886

RESUMEN

PURPOSE: DISP1 encodes a transmembrane protein that regulates the secretion of the morphogen, Sonic hedgehog, a deficiency of which is a major cause of holoprosencephaly (HPE). This disorder covers a spectrum of brain and midline craniofacial malformations. The objective of the present study was to better delineate the clinical phenotypes associated with division transporter dispatched-1 (DISP1) variants. METHODS: This study was based on the identification of at least 1 pathogenic variant of the DISP1 gene in individuals for whom detailed clinical data were available. RESULTS: A total of 23 DISP1 variants were identified in heterozygous, compound heterozygous or homozygous states in 25 individuals with midline craniofacial defects. Most cases were minor forms of HPE, with craniofacial features such as orofacial cleft, solitary median maxillary central incisor, and congenital nasal pyriform aperture stenosis. These individuals had either monoallelic loss-of-function variants or biallelic missense variants in DISP1. In individuals with severe HPE, the DISP1 variants were commonly found associated with a variant in another HPE-linked gene (ie, oligogenic inheritance). CONCLUSION: The genetic findings we have acquired demonstrate a significant involvement of DISP1 variants in the phenotypic spectrum of midline defects. This underlines its importance as a crucial element in the efficient secretion of Sonic hedgehog. We also demonstrated that the very rare solitary median maxillary central incisor and congenital nasal pyriform aperture stenosis combination is part of the DISP1-related phenotype. The present study highlights the clinical risks to be flagged up during genetic counseling after the discovery of a pathogenic DISP1 variant.


Asunto(s)
Alelos , Holoprosencefalia , Fenotipo , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Anodoncia , Labio Leporino/genética , Labio Leporino/patología , Fisura del Paladar/genética , Fisura del Paladar/patología , Anomalías Craneofaciales/genética , Anomalías Craneofaciales/patología , Heterocigoto , Holoprosencefalia/genética , Holoprosencefalia/patología , Homocigoto , Incisivo/anomalías , Proteínas de la Membrana/genética , Mutación Missense/genética
5.
Epilepsia ; 65(4): 1029-1045, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38135915

RESUMEN

OBJECTIVE: The postsynaptic density protein of excitatory neurons PSD-95 is encoded by discs large MAGUK scaffold protein 4 (DLG4), de novo pathogenic variants of which lead to DLG4-related synaptopathy. The major clinical features are developmental delay, intellectual disability (ID), hypotonia, sleep disturbances, movement disorders, and epilepsy. Even though epilepsy is present in 50% of the individuals, it has not been investigated in detail. We describe here the phenotypic spectrum of epilepsy and associated comorbidities in patients with DLG4-related synaptopathy. METHODS: We included 35 individuals with a DLG4 variant and epilepsy as part of a multicenter study. The DLG4 variants were detected by the referring laboratories. The degree of ID, hypotonia, developmental delay, and motor disturbances were evaluated by the referring clinician. Data on awake and sleep electroencephalography (EEG) and/or video-polygraphy and brain magnetic resonance imaging were collected. Antiseizure medication response was retrospectively assessed by the referring clinician. RESULTS: A large variety of seizure types was reported, although focal seizures were the most common. Encephalopathy related to status epilepticus during slow-wave sleep (ESES)/developmental epileptic encephalopathy with spike-wave activation during sleep (DEE-SWAS) was diagnosed in >25% of the individuals. All but one individual presented with neurodevelopmental delay. Regression in verbal and/or motor domains was observed in all individuals who suffered from ESES/DEE-SWAS, as well as some who did not. We could not identify a clear genotype-phenotype relationship even between individuals with the same DLG4 variants. SIGNIFICANCE: Our study shows that a subgroup of individuals with DLG4-related synaptopathy have DEE, and approximately one fourth of them have ESES/DEE-SWAS. Our study confirms DEE as part of the DLG4-related phenotypic spectrum. Occurrence of ESES/DEE-SWAS in DLG4-related synaptopathy requires proper investigation with sleep EEG.


Asunto(s)
Encefalopatías , Epilepsia Generalizada , Epilepsia , Discapacidad Intelectual , Humanos , Estudios Retrospectivos , Hipotonía Muscular , Epilepsia/diagnóstico por imagen , Epilepsia/genética , Epilepsia/complicaciones , Encefalopatías/genética , Convulsiones/complicaciones , Epilepsia Generalizada/complicaciones , Electroencefalografía/métodos , Discapacidad Intelectual/genética , Discapacidad Intelectual/complicaciones , Homólogo 4 de la Proteína Discs Large/genética
6.
Genet Med ; 25(7): 100839, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37057675

RESUMEN

PURPOSE: LHX2 encodes the LIM homeobox 2 transcription factor (LHX2), which is highly expressed in brain and well conserved across species, but it has not been clearly linked to neurodevelopmental disorders (NDDs) to date. METHODS: Through international collaboration, we identified 19 individuals from 18 families with variable neurodevelopmental phenotypes, carrying a small chromosomal deletion, likely gene-disrupting or missense variants in LHX2. Functional consequences of missense variants were investigated in cellular systems. RESULTS: Affected individuals presented with developmental and/or behavioral abnormalities, autism spectrum disorder, variable intellectual disability, and microcephaly. We observed nucleolar accumulation for 2 missense variants located within the DNA-binding HOX domain, impaired interaction with co-factor LDB1 for another variant located in the protein-protein interaction-mediating LIM domain, and impaired transcriptional activation by luciferase assay for 4 missense variants. CONCLUSION: We implicate LHX2 haploinsufficiency by deletion and likely gene-disrupting variants as causative for a variable NDD. Our findings suggest a loss-of-function mechanism also for likely pathogenic LHX2 missense variants. Together, our observations underscore the importance of LHX2 in the nervous system and for variable neurodevelopmental phenotypes.


Asunto(s)
Trastorno del Espectro Autista , Discapacidad Intelectual , Trastornos del Neurodesarrollo , Humanos , Proteínas con Homeodominio LIM/genética , Trastorno del Espectro Autista/genética , Haploinsuficiencia/genética , Trastornos del Neurodesarrollo/patología , Factores de Transcripción/genética , Discapacidad Intelectual/genética , Discapacidad Intelectual/complicaciones
7.
Prenat Diagn ; 43(6): 734-745, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36914926

RESUMEN

OBJECTIVE: We aimed to gather fetal cases carrying a 7q11.23 copy number variation (CNV) and collect precise clinical data to broaden knowledge of antenatal features in these syndromes. METHODS: We retrospectively recruited unrelated cases with 7q11.23 deletion, known as Williams-Beuren syndrome (WBS), or 7q11.23 duplication who had prenatal ultrasound findings. We collected laboratory and clinical data, fetal ultrasound, cardiac ultrasound and fetal autopsy reports from 18 prenatal diagnostic centers throughout France. RESULTS: 40 fetuses with WBS were collected and the most common features were intra-uterine growth retardation (IUGR) (70.0%, 28/40), cardiovascular defects (30.0%, 12/40), polyhydramnios (17.5%, 7/40) and protruding tongue (15.0%, 6/40). Fetal autopsy reports were available for 11 cases and were compared with ultrasound prenatal features. Four cases of fetuses with 7q11.23 microduplication were collected and prenatal ultrasound signs were variable and often isolated. CONCLUSION: This work strengthens the fact that 7q11.23 CNVs are associated with a broad spectrum of antenatal presentations. IUGR and cardiovascular defects were the most frequent ultrasound signs. By reporting the biggest series of antenatal WBS, we aim to better delineate distinctive signs in fetuses with 7q11.23 CNVs.


Asunto(s)
Síndrome de Williams , Humanos , Femenino , Embarazo , Síndrome de Williams/diagnóstico por imagen , Síndrome de Williams/genética , Síndrome de Williams/complicaciones , Variaciones en el Número de Copia de ADN , Estudios Retrospectivos , Retardo del Crecimiento Fetal , Ultrasonografía
8.
Genet Med ; 24(5): 1096-1107, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35063350

RESUMEN

PURPOSE: Rare genetic variants in CDK13 are responsible for CDK13-related disorder (CDK13-RD), with main clinical features being developmental delay or intellectual disability, facial features, behavioral problems, congenital heart defect, and seizures. In this paper, we report 18 novel individuals with CDK13-RD and provide characterization of genome-wide DNA methylation. METHODS: We obtained clinical phenotype and neuropsychological data for 18 and 10 individuals, respectively, and compared this series with the literature. We also compared peripheral blood DNA methylation profiles in individuals with CDK13-RD, controls, and other neurodevelopmental disorders episignatures. Finally, we developed a support vector machine-based classifier distinguishing CDK13-RD and non-CDK13-RD samples. RESULTS: We reported health and developmental parameters, clinical data, and neuropsychological profile of individuals with CDK13-RD. Genome-wide differential methylation analysis revealed a global hypomethylated profile in individuals with CDK13-RD in a highly sensitive and specific model that could aid in reclassifying variants of uncertain significance. CONCLUSION: We describe the novel features such as anxiety disorder, cryptorchidism, and disrupted sleep in CDK13-RD. We define a CDK13-RD DNA methylation episignature as a diagnostic tool and a defining functional feature of the evolving clinical presentation of this disorder. We also show overlap of the CDK13 DNA methylation profile in an individual with a functionally and clinically related CCNK-related disorder.


Asunto(s)
Discapacidad Intelectual , Trastornos del Neurodesarrollo , Proteína Quinasa CDC2/genética , Metilación de ADN/genética , Epigénesis Genética/genética , Humanos , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Masculino , Trastornos del Neurodesarrollo/genética , Fenotipo
9.
Pediatr Dev Pathol ; 25(5): 548-552, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35481434

RESUMEN

Holoprosencephaly (HPE) is a clinically and genetically heterogeneous disease, which can be associated with various prenatal comorbidities not always detectable on prenatal ultrasound. We report on the case of a foetus carrying a semi-lobar HPE diagnosed at ultrasound, for which a fetal autopsy and a whole exome sequencing were performed following a medical termination of pregnancy. Neuropathological examination confirmed the semi-lobar HPE and general autopsy disclosed a total pancreas agenesis. Whole exome sequencing found the CNOT1 missense c.1603C>T, p.(Arg535Cys), occurring de novo in the foetus. The same variant was previously reported in 5 unrelated children. All individuals had HPE, and 4 out of 5 presented endo- and exocrine pancreatic insufficiency or total pancreas agenesis. CNOT1 encodes a subunit of the CCRN4-NOT complex, expressed at the early stage of embryonic development. This report is the first fetal description of the phenotype associating HPE and pancreatic agenesis linked to the recurrent CNOT1 missense c.1603C>T, p.(Arg535Cys). This finding strengthens the hypothesis of a specific recurrent variant associated with a particular phenotype of HPE and pancreas agenesis. The fetal autopsy that revealed the pancreas agenesis was crucial in guiding the genetic diagnosis and enabling accurate genetic counselling.


Asunto(s)
Holoprosencefalia , Femenino , Feto/patología , Holoprosencefalia/diagnóstico , Holoprosencefalia/genética , Holoprosencefalia/patología , Humanos , Fenotipo , Embarazo , Síndrome , Factores de Transcripción/genética
10.
J Med Genet ; 58(6): 400-413, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32732226

RESUMEN

PURPOSE: Molecular diagnosis based on singleton exome sequencing (sES) is particularly challenging in fetuses with multiple congenital abnormalities (MCA). Indeed, some studies reveal a diagnostic yield of about 20%, far lower than in live birth individuals showing developmental abnormalities (30%), suggesting that standard analyses, based on the correlation between clinical hallmarks described in postnatal syndromic presentations and genotype, may underestimate the impact of the genetic variants identified in fetal analyses. METHODS: We performed sES in 95 fetuses with MCA. Blind to phenotype, we applied a genotype-first approach consisting of combined analyses based on variants annotation and bioinformatics predictions followed by reverse phenotyping. Initially applied to OMIM-morbid genes, analyses were then extended to all genes. We complemented our approach by using reverse phenotyping, variant segregation analysis, bibliographic search and data sharing in order to establish the clinical significance of the prioritised variants. RESULTS: sES rapidly identified causal variant in 24/95 fetuses (25%), variants of unknown significance in OMIM genes in 8/95 fetuses (8%) and six novel candidate genes in 6/95 fetuses (6%). CONCLUSIONS: This method, based on a genotype-first approach followed by reverse phenotyping, shed light on unexpected fetal phenotype-genotype correlations, emphasising the relevance of prenatal studies to reveal extreme clinical presentations associated with well-known Mendelian disorders.


Asunto(s)
Anomalías Múltiples/genética , Anomalías Congénitas/genética , Exoma , Feto/anomalías , Estudios de Asociación Genética , Estudios de Cohortes , Exoma/genética , Genotipo , Humanos , Análisis de Secuencia de ADN
11.
Genet Med ; 23(8): 1484-1491, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33833411

RESUMEN

PURPOSE: Hypomelanosis of Ito (HI) is a skin marker of somatic mosaicism. Mosaic MTOR pathogenic variants have been reported in HI with brain overgrowth. We sought to delineate further the pigmentary skin phenotype and clinical spectrum of neurodevelopmental manifestations of MTOR-related HI. METHODS: From two cohorts totaling 71 patients with pigmentary mosaicism, we identified 14 patients with Blaschko-linear and one with flag-like pigmentation abnormalities, psychomotor impairment or seizures, and a postzygotic MTOR variant in skin. Patient records, including brain magnetic resonance image (MRI) were reviewed. Immunostaining (n = 3) for melanocyte markers and ultrastructural studies (n = 2) were performed on skin biopsies. RESULTS: MTOR variants were present in skin, but absent from blood in half of cases. In a patient (p.[Glu2419Lys] variant), phosphorylation of p70S6K was constitutively increased. In hypopigmented skin of two patients, we found a decrease in stage 4 melanosomes in melanocytes and keratinocytes. Most patients (80%) had macrocephaly or (hemi)megalencephaly on MRI. CONCLUSION: MTOR-related HI is a recognizable neurocutaneous phenotype of patterned dyspigmentation, epilepsy, intellectual deficiency, and brain overgrowth, and a distinct subtype of hypomelanosis related to somatic mosaicism. Hypopigmentation may be due to a defect in melanogenesis, through mTORC1 activation, similar to hypochromic patches in tuberous sclerosis complex.


Asunto(s)
Hipopigmentación , Megalencefalia , Humanos , Hipopigmentación/genética , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Mosaicismo , Fenotipo , Serina-Treonina Quinasas TOR/genética
12.
Hum Mutat ; 41(12): 2167-2178, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33131162

RESUMEN

Herein, we report the screening of a large panel of genes in a series of 80 fetuses with congenital heart defects (CHDs) and/or heterotaxy and no cytogenetic anomalies. There were 49 males (61%/39%), with a family history in 28 cases (35%) and no parental consanguinity in 77 cases (96%). All fetuses had complex CHD except one who had heterotaxy and midline anomalies while 52 cases (65%) had heterotaxy in addition to CHD. Altogether, 29 cases (36%) had extracardiac and extra-heterotaxy anomalies. A pathogenic variant was found in 10/80 (12.5%) cases with a higher percentage in the heterotaxy group (8/52 cases, 15%) compared with the non-heterotaxy group (2/28 cases, 7%), and in 3 cases with extracardiac and extra-heterotaxy anomalies (3/29, 10%). The inheritance was recessive in six genes (DNAI1, GDF1, MMP21, MYH6, NEK8, and ZIC3) and dominant in two genes (SHH and TAB2). A homozygous pathogenic variant was found in three cases including only one case with known consanguinity. In conclusion, after removing fetuses with cytogenetic anomalies, next-generation sequencing discovered a causal variant in 12.5% of fetal cases with CHD and/or heterotaxy. Genetic counseling for future pregnancies was greatly improved. Surprisingly, unexpected consanguinity accounts for 20% of cases with identified pathogenic variants.


Asunto(s)
Feto/anomalías , Cardiopatías Congénitas/genética , Síndrome de Heterotaxia/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Análisis Citogenético , Familia , Femenino , Heterocigoto , Homocigoto , Humanos , Masculino , Mutación/genética , Linaje
13.
Brain ; 142(9): 2617-2630, 2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-31327001

RESUMEN

The underpinnings of mild to moderate neurodevelopmental delay remain elusive, often leading to late diagnosis and interventions. Here, we present data on exome and genome sequencing as well as array analysis of 13 individuals that point to pathogenic, heterozygous, mostly de novo variants in WDFY3 (significant de novo enrichment P = 0.003) as a monogenic cause of mild and non-specific neurodevelopmental delay. Nine variants were protein-truncating and four missense. Overlapping symptoms included neurodevelopmental delay, intellectual disability, macrocephaly, and psychiatric disorders (autism spectrum disorders/attention deficit hyperactivity disorder). One proband presented with an opposing phenotype of microcephaly and the only missense-variant located in the PH-domain of WDFY3. Findings of this case are supported by previously published data, demonstrating that pathogenic PH-domain variants can lead to microcephaly via canonical Wnt-pathway upregulation. In a separate study, we reported that the autophagy scaffolding protein WDFY3 is required for cerebral cortical size regulation in mice, by controlling proper division of neural progenitors. Here, we show that proliferating cortical neural progenitors of human embryonic brains highly express WDFY3, further supporting a role for this molecule in the regulation of prenatal neurogenesis. We present data on Wnt-pathway dysregulation in Wdfy3-haploinsufficient mice, which display macrocephaly and deficits in motor coordination and associative learning, recapitulating the human phenotype. Consequently, we propose that in humans WDFY3 loss-of-function variants lead to macrocephaly via downregulation of the Wnt pathway. In summary, we present WDFY3 as a novel gene linked to mild to moderate neurodevelopmental delay and intellectual disability and conclude that variants putatively causing haploinsufficiency lead to macrocephaly, while an opposing pathomechanism due to variants in the PH-domain of WDFY3 leads to microcephaly.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Relacionadas con la Autofagia/genética , Encéfalo/embriología , Encéfalo/patología , Variación Genética/genética , Trastornos del Neurodesarrollo/genética , Trastornos del Neurodesarrollo/patología , Proteínas Adaptadoras Transductoras de Señales/química , Adolescente , Animales , Proteínas Relacionadas con la Autofagia/química , Niño , Preescolar , Femenino , Humanos , Masculino , Ratones , Ratones Transgénicos , Tamaño de los Órganos , Estructura Secundaria de Proteína
14.
Hum Genet ; 138(4): 363-374, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30838450

RESUMEN

Neural tube defect disorders are developmental diseases that originate from an incomplete closure of the neural tube during embryogenesis. Despite high prevalence-1 out of 3000 live births-their etiology is not yet established and both environmental and genetic factors have been proposed, with a heritability rate of about 60%. Studies in mouse models as well as in human have further suggested a multifactorial pattern of inheritance for neural tube defect disorders. Here, we report results obtained from clinical diagnosis and NGS analysis of a cohort composed of 52 patients. Using a candidate gene panel approach, we identified variants in known genes of planar cell polarity (PCP) pathway, although with higher prevalence than previously reported. Our study also reveals variants in novel genes such as FREM2 and DISP1. Altogether, these results confirm the implication of the PCP genes and involve the FRAS/FREM2 complex and Sonic Hedgehog signaling as novel components in the appearance of NTDs.


Asunto(s)
Polaridad Celular/genética , Estudios de Asociación Genética/métodos , Defectos del Tubo Neural/genética , Análisis de Secuencia de ADN/métodos , Adulto , Animales , Niño , Estudios de Cohortes , Análisis Mutacional de ADN/métodos , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Ratones , Defectos del Tubo Neural/patología , Embarazo , Transducción de Señal/genética , Transcriptoma
16.
J Med Genet ; 55(6): 422-429, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29459493

RESUMEN

BACKGROUND: Segmentation defects of the vertebrae (SDV) are non-specific features found in various syndromes. The molecular bases of SDV are not fully elucidated due to the wide range of phenotypes and classification issues. The genes involved are in the Notch signalling pathway, which is a key system in somitogenesis. Here we report on mutations identified in a diagnosis cohort of SDV. We focused on spondylocostal dysostosis (SCD) and the phenotype of these patients in order to establish a diagnostic strategy when confronted with SDV. PATIENTS AND METHODS: We used DNA samples from a cohort of 73 patients and performed targeted sequencing of the five known SCD-causing genes (DLL3, MESP2, LFNG, HES7 and TBX6) in the first 48 patients and whole-exome sequencing (WES) in 28 relevant patients. RESULTS: Ten diagnoses, including four biallelic variants in TBX6, two biallelic variants in LFNG and DLL3, and one in MESP2 and HES7, were made with the gene panel, and two diagnoses, including biallelic variants in FLNB and one variant in MEOX1, were made by WES. The diagnostic yield of the gene panel was 10/73 (13.7%) in the global cohort but 8/10 (80%) in the subgroup meeting the SCD criteria; the diagnostic yield of WES was 2/28 (8%). CONCLUSION: After negative array CGH, targeted sequencing of the five known SCD genes should only be performed in patients who meet the diagnostic criteria of SCD. The low proportion of candidate genes identified by WES in our cohort suggests the need to consider more complex genetic architectures in cases of SDV.


Asunto(s)
Enfermedades del Desarrollo Óseo/genética , Secuenciación del Exoma , Adolescente , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Enfermedades del Desarrollo Óseo/fisiopatología , Niño , Preescolar , Femenino , Glicosiltransferasas/genética , Humanos , Lactante , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Proteínas de la Membrana/genética , Mutación , Linaje , Fenotipo , Columna Vertebral/metabolismo , Columna Vertebral/patología , Proteínas de Dominio T Box/genética
17.
Am J Med Genet A ; 176(7): 1610-1613, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29704304

RESUMEN

Ciliopathies comprise a group of clinically heterogeneous and overlapping disorders with a wide spectrum of phenotypes ranging from prenatal lethality to adult-onset disorders. Pathogenic variants in more than 100 ciliary protein-encoding genes have been described, most notably those involved in intraflagellar transport (IFT) which comprises two protein complexes, responsible for retrograde (IFT-A) and anterograde transport (IFT-B). Here we describe a fetus with an unclassified severe ciliopathy phenotype including short ribs, polydactyly, bilateral renal agenesis, and imperforate anus, with compound heterozygosity for c.118_125del, p.(Thr40Glyfs*11) and a c.352 +1G > T in IFT27, which encodes a small GTPase component of the IFT-B complex. We conclude that bilateral renal agenesis is a rare feature of this severe ciliopathy and this report highlights the phenotypic overlap of Pallister-Hall syndrome and ciliopathies. The phenotype in patients with IFT27 gene variants is wide ranging from Bardet-Biedl syndrome to a lethal phenotype.


Asunto(s)
Ciliopatías/patología , Anomalías Congénitas/patología , Enfermedades Fetales/patología , Enfermedades Renales/congénito , Riñón/anomalías , Mutación , Proteínas de Unión al GTP rab/genética , Ciliopatías/genética , Anomalías Congénitas/genética , Resultado Fatal , Femenino , Enfermedades Fetales/genética , Humanos , Riñón/patología , Enfermedades Renales/genética , Enfermedades Renales/patología , Masculino , Linaje
18.
Prenat Diagn ; 38(10): 772-778, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29949202

RESUMEN

We report a multiplex family with a GATA1 gene mutation responsible for a massive fetal cerebral hemorrhage occurring at 36 weeks. Two other stillbirth cousins presented with fetal hydrops and congenital hemochromatosis' phenotype at 37 and 12 weeks of gestation. Molecular screening revealed the presence of a c.613G>A pathogenic allelic variation in exon 4 of GATA1 gene in the 3 male siblings and their carrier mothers. The diagnosis of a GATA1 gene mutation may be suspected in cases of male fetuses with intracerebral bleeding, particularly if a history of prior fetal loss(es) and mild maternal thrombocytopenia are also present.


Asunto(s)
Hemorragia Cerebral/genética , Enfermedades Fetales/genética , Factor de Transcripción GATA1/genética , Adulto , Femenino , Genes Ligados a X , Humanos , Mutación , Embarazo
19.
Am J Med Genet C Semin Med Genet ; 175(4): 417-430, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29178447

RESUMEN

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.


Asunto(s)
Síndrome CHARGE/diagnóstico , Síndrome CHARGE/genética , Estudios de Asociación Genética , Genotipo , Fenotipo , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/genética , Adolescente , Adulto , Alelos , Sustitución de Aminoácidos , Sistema Nervioso Central/anomalías , Niño , Preescolar , Estudios de Cohortes , Nervios Craneales/anomalías , ADN Helicasas/genética , Proteínas de Unión al ADN/genética , Femenino , Francia , Pruebas Genéticas , Humanos , Lactante , Masculino , Técnicas de Diagnóstico Molecular , Adulto Joven
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