RESUMO
BACKGROUND: The Ehlers-Danlos syndromes (EDS) are heritable disorders of connective tissue (HDCT), reclassified in the 2017 nosology into 13 subtypes. The genetic basis for hypermobile Ehlers-Danlos syndrome (hEDS) remains unknown. METHODS: Whole exome sequencing (WES) was undertaken on 174 EDS patients recruited from a national diagnostic service for complex EDS and a specialist clinic for hEDS. Patients had already undergone expert phenotyping, laboratory investigation and gene sequencing, but were without a genetic diagnosis. Filtered WES data were reviewed for genes underlying Mendelian disorders and loci reported in EDS linkage, transcriptome and genome-wide association studies (GWAS). A genetic burden analysis (Minor Allele Frequency (MAF) <0.05) incorporating 248 Avon Longitudinal Study of Parents and Children (ALSPAC) controls sequenced as part of the UK10K study was undertaken using TASER methodology. RESULTS: Heterozygous pathogenic (P) or likely pathogenic (LP) variants were identified in known EDS and Loeys-Dietz (LDS) genes. Multiple variants of uncertain significance where segregation and functional analysis may enable reclassification were found in genes associated with EDS, LDS, heritable thoracic aortic disease (HTAD), Mendelian disorders with EDS symptomatology and syndromes with EDS-like features. Genetic burden analysis revealed a number of novel loci, although none reached the threshold for genome-wide significance. Variants with biological plausibility were found in genes and pathways not currently associated with EDS or HTAD. CONCLUSIONS: We demonstrate the clinical utility of large panel-based sequencing and WES for patients with complex EDS in distinguishing rare EDS subtypes, LDS and related syndromes. Although many of the P and LP variants reported in this cohort would be identified with current panel testing, they were not at the time of this study, highlighting the use of extended panels and WES as a clinical tool for complex EDS. Our results are consistent with the complex genetic architecture of EDS and suggest a number of novel hEDS and HTAD candidate genes and pathways.
Assuntos
Doenças do Tecido Conjuntivo , Síndrome de Ehlers-Danlos , Criança , Humanos , Estudo de Associação Genômica Ampla , Estudos Longitudinais , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/genéticaRESUMO
Ehlers-Danlos syndromes (EDS) is an umbrella term describing 14 types, of which 13 are rare and monogenic, with overlapping features of joint hypermobility, skin, and vascular fragility, and generalised connective tissue friability. Hypermobile EDS currently has no identified genetic cause. Most of the rare monogenic EDS types can have neurological features, which are often part of major or minor diagnostic criteria for each type. This review aims to highlight the neurological features and other key characteristics of these EDS types. This should improve recognition of these features, enabling more timely consideration and confirmation or exclusion through genetic testing. In practice, many healthcare professionals still refer to patients as having 'EDS'. However, the different EDS types have distinct clinical features as well as different underlying genetic causes and pathogenic mechanisms, and each requires bespoke management and surveillance. Defining the EDS type is therefore crucial, as EDS is not in itself a diagnosis.
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Síndrome de Ehlers-Danlos , Instabilidade Articular , Doenças Vasculares , Humanos , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/genética , Síndrome de Ehlers-Danlos/patologia , Testes Genéticos , Instabilidade Articular/diagnóstico , Instabilidade Articular/genéticaRESUMO
The vast majority of reported (likely) pathogenic missense variants in the genes coding for the fibrillar collagens leads to the substitution of one of the obligatory glycine residues in the Gly-Xaa-Yaa repeat sequence of the triple helical domain. Their phenotypic consequences and deleterious effects have been well-documented. However, with increasing access to molecular diagnostic testing based on next-generation sequencing techniques, such as sequencing of multi-gene panels and whole-exome sequencing, non-glycine substitutions are more frequently identified in individuals suspected to have a heritable collagen disorder, but their pathogenic effect is often difficult to predict.Some specific non-glycine substitutions in the proα1(I)- (p.(Arg312Cys)) and proα1(III)- (glutamic acid to lysine at different positions) collagen chain have been identified in a number of individuals presenting a phenotype showing features of both classical and vascular Ehlers-Danlos syndrome. The number of reported individuals with these defects is currently very low, and several of these non-glycine substitutions had initially been categorised as variants of unknown significance (VUS), complicating early diagnosis, accurate counselling, management guidelines, and correct classification. This collaborative study reports on the phenotype of 22 and 7 individuals harbouring these rare variants in COL1A1 and COL3A1, respectively, expanding our knowledge on clinical presentation, phenotypic variability, and natural history, and informing on the risk for potentially life-threatening events, such as vascular, gastro-intestinal, and pregnancy-related complications.
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Cadeia alfa 1 do Colágeno Tipo I , Síndrome de Ehlers-Danlos , Colágeno , Colágeno Tipo III/genética , Síndrome de Ehlers-Danlos/complicações , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/genética , Humanos , Mutação , FenótipoRESUMO
AIM: Periodontal Ehlers-Danlos syndrome (pEDS) is a monogenic type of Ehlers-Danlos syndrome characterized by periodontal destruction at a young age. The present study aimed to document the oral phenotype of pEDS based on prospective clinical investigations. MATERIALS AND METHODS: Thirty-five adult individuals from 13 families with a clinically and genetically confirmed diagnosis of pEDS underwent a systematic oral assessment. RESULTS: Periodontitis stage 3 or 4 or edentulism due to periodontal destruction were diagnosed in 94% of the individuals. First permanent tooth loss was reported at the age of 21.5 years (median; range 13-43 years). Deep periodontal pockets were infrequent, with 94% measuring <4 mm. However, there was increased clinical attachment loss (CAL) averaging 8 mm (range 4-13 mm), and the probability of being edentate between the age of 35 and 44 years was 28-47% compared with less than 0.25% of the general population. Radiographic anomalous findings were only found in a portion of subjects and consisted of fused roots of maxillary second molars (81%), root hypoplasia (57%), taurodontism (26%) and tooth rotation of premolars (67%). As such, radiographic findings are not considered common characteristics of pEDS. CONCLUSIONS: Characteristic oral traits of pEDS in adults are severe CAL with shallow probing depths and marked gingival recession. This is complemented by a lack of attached gingiva. These indications need to be paralleled by genetic analyses to diagnose pEDS unambiguously.
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Síndrome de Ehlers-Danlos , Retração Gengival , Periodontite , Humanos , Síndrome de Ehlers-Danlos/complicações , Estudos Prospectivos , Retração Gengival/etiologia , Dente Pré-Molar , Perda da Inserção PeriodontalRESUMO
PURPOSE: We report prospective clinical investigations of children affected with periodontal Ehlers-Danlos syndrome (pEDS). The main clinical features of pEDS in adults are early severe periodontitis, generalized lack of attached gingiva, and pretibial hemosiderin plaques due to dominant pathogenic variants in the C1R or C1S genes. METHODS: Nineteen children with a parent diagnosed with molecularly confirmed pEDS underwent physical examination including oral and radiological investigations followed by genetic testing. RESULTS: The only consistent manifestation of pEDS in childhood was a characteristic gingival phenotype: generalized lack of attached gingiva. All children with this gingival phenotype had inherited the familial pathogenic variant (n = 12) whereas the gingival phenotype was absent in children without the familial pathogenic variant (n = 7). Easy bruising was reported in eight affected and zero unaffected children. Other manifestations of pEDS were rarely present in children. Only 2/12 affected children aged 8 and 13 years fulfilled the clinical criteria for pEDS. CONCLUSION: Generalized lack of attached gingiva is a pathognomonic feature of pEDS and the only clinical finding that is consistently present in affected adults and children. This is important because an early diagnosis may facilitate better dental hygiene in childhood, which may be essential to prevent early dental loss.
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Síndrome de Ehlers-Danlos , Periodontite , Adulto , Criança , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/genética , Gengiva , Humanos , Fenótipo , Estudos ProspectivosRESUMO
BACKGROUND: The Ehlers-Danlos syndromes (EDS) are a group of connective tissue disorders with several recognised types. Patients with a type of EDS have connective tissue abnormalities resulting in a varying degree of joint hypermobility, skin and vascular fragility and generalised tissue friability. Classical EDS (cEDS) typically occurs as a result of dominant pathogenic variants in COL5A1 or COL5A2. The cardinal features of cEDS are hyperextensible skin, atrophic scarring and joint hypermobility. Arterial complications are more characteristically a feature of vascular EDS although individual cases of arterial events in cEDS have been reported. METHODS: A cohort of 154 patients with a clinical diagnosis of cEDS from the UK was analysed. RESULTS: Seven patients (4.5%) with a diagnosis of cEDS (four pathogenic, one likely pathogenic and two variants of uncertain significance in COL5A1) who had experienced arterial complications were identified. Arterial complications mostly involved medium-sized vessels and also two abdominal aortic aneurysms. No unique clinical features were identified in this group of patients. CONCLUSION: There is a possible increased risk of arterial complications in patients with cEDS, although not well-defined. Clinicians need to be aware of this possibility when presented with a patient with an arterial complication and features of cEDS. Long-term management in families with cEDS and a vascular complication should be individually tailored to the patient's history and their family's history of vascular events.
Assuntos
Colágeno Tipo V/genética , Doenças do Tecido Conjuntivo/genética , Síndrome de Ehlers-Danlos/genética , Adulto , Idoso , Doenças do Tecido Conjuntivo/patologia , Feminino , Predisposição Genética para Doença , Humanos , Instabilidade Articular/genética , Instabilidade Articular/patologia , Masculino , Pessoa de Meia-Idade , Mutação/genética , Anormalidades da Pele/genética , Anormalidades da Pele/patologiaRESUMO
PURPOSE: Currently, 31 patients with classical-like EDS (clEDS) due to tenascin-X deficiency have been reported in the literature. We report on the clinical and molecular characteristics of 20 additional patients with clEDS to expand knowledge and to enable improved management of this rare genetic disorder. METHODS: Patients diagnosed with clEDS by the national EDS service in the UK (n = 21) and abroad (n = 1) were asked for consent for publication of their clinical and molecular data. RESULTS: Of 22 patients, 20 consented. All patients had typical features of clEDS: joint hypermobility, easy bruising, and skin hyperextensibility without atrophic scars. Importantly, 3/20 patients experienced gastrointestinal complications consisting of small or large bowel ruptures and one esophageal rupture. Other notable observations included two separate occurrences of spontaneous compartment syndrome, suspicion of nonaccidental injury due to significant bruising, and significant clinical variability regarding the debilitating effect of joint dislocations. CONCLUSIONS: We propose a predisposition to tissue fragility, particularly of the gastrointestinal tract in patients with clEDS. As such, clinical and molecular confirmation of this diagnosis is essential. It is recommended to follow up these patients closely to understand the natural history to develop better recommendations for management.
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Síndrome de Ehlers-Danlos , Instabilidade Articular , Anormalidades da Pele , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/genética , Matriz Extracelular , Humanos , Instabilidade Articular/diagnóstico , Instabilidade Articular/genéticaRESUMO
Arthrochalasia Ehlers-Danlos syndrome (aEDS) is a rare autosomal dominant connective tissue disorder that is characterized by congenital bilateral hip dislocations, severe generalized joint hypermobility, recurrent joint (sub)luxations, and skin hyperextensibility. To date, 42 patients with aEDS have been published. We report 12 patients with aEDS from 10 families with 6 unpublished individuals and follow-up data on 6 adult patients. The clinical features are largely comparable with patients reported in the literature. Most (n = 10) patients had variants leading to (partial) loss of exon 6 of the COL1A1 or COL1A2 genes. One patient did not have a previously reported likely pathogenic COL1A1 variant. Data regarding management were retrieved. Hip surgery was performed in 5/12 patients and 3/12 patients underwent spinal surgery. As much as 4/12 patients were wheelchair-bound or unable to walk unaided. Fractures were present in 9/12 individuals with 1 patient requiring bisphosphonate treatment. Echocardiograms were performed in 10 patients and 2 individuals showed an abnormality likely unrelated to aEDS. One patient gave birth to two affected children and went through preterm labor requiring medication but had no additional complications. Of the eight adults in our cohort, the majority entered a career. Our data point toward a genotype-phenotype relationship with individuals with aEDS due to pathogenic COL1A1 variants causing complete or partial loss of exon 6 being more severely affected regarding musculoskeletal features. There is a significant lack of knowledge with regard to management of aEDS, particularly in adulthood. As such, systematic follow-up and multidisciplinary treatment is essential.
Assuntos
Colágeno Tipo I/genética , Síndrome de Ehlers-Danlos/genética , Luxação Congênita de Quadril/genética , Adolescente , Adulto , Criança , Pré-Escolar , Cadeia alfa 1 do Colágeno Tipo I , Síndrome de Ehlers-Danlos/epidemiologia , Síndrome de Ehlers-Danlos/fisiopatologia , Éxons/genética , Feminino , Predisposição Genética para Doença , Luxação Congênita de Quadril/epidemiologia , Luxação Congênita de Quadril/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/genética , Linhagem , Fenótipo , Anormalidades da Pele/genética , Anormalidades da Pele/fisiopatologia , Adulto JovemRESUMO
With advances in genetic testing and improved access to such advances, whole exome sequencing is becoming a first-line investigation in clinical work-up of children with developmental delay/intellectual disability (ID). As a result, the need to understand the importance of genetic variants and its effect on the clinical phenotype is increasing. Here, we report on the largest cohort of patients with HNRNPU variants. These 21 patients follow on from the previous study published by Yates et al. in 2017 from our group predominantly identified from the Deciphering Developmental Disorders study that reported seven patients with HNRNPU variants. All the probands reported here have a de novo loss-of-function variant. These probands have craniofacial dysmorphic features, in the majority including widely spaced teeth, microcephaly, high arched eyebrows, and palpebral fissure abnormalities. Many of the patients in the group also have moderate to severe ID and seizures that tend to start in early childhood. This series has allowed us to define a novel neurodevelopmental syndrome, with a likely mechanism of haploinsufficiency, and expand substantially on already published literature on HNRNPU-related neurodevelopmental syndrome.
Assuntos
Ribonucleoproteínas Nucleares Heterogêneas Grupo U/genética , Transtornos do Neurodesenvolvimento/etiologia , Adolescente , Encéfalo/diagnóstico por imagem , Criança , Pré-Escolar , Anormalidades Craniofaciais/etiologia , Feminino , Haploinsuficiência/genética , Humanos , Lactente , Deficiência Intelectual/genética , Masculino , Microcefalia/etiologia , Transtornos do Neurodesenvolvimento/genética , Gravidez , Convulsões/genética , SíndromeRESUMO
PURPOSE: The Ehlers-Danlos syndromes (EDS) are a group of rare inherited connective tissue disorders. Vascular EDS (vEDS) is caused by pathogenic variants in COL3A1, most frequently glycine substitutions. We describe the phenotype of the largest series of vEDS patients with glutamic acid to lysine substitutions (Glu>Lys) in COL3A1, which were all previously considered to be variants of unknown significance. METHODS: Clinical and molecular data for seven families with three different Glu>Lys substitutions in COL3A1 were analyzed. RESULTS: These Glu>Lys variants were reclassified from variants of unknown significance to either pathogenic or likely pathogenic in accordance with American College of Medical Genetics and Genomics guidelines. All individuals with these atypical variants exhibited skin hyperextensibility as seen in individuals with classical EDS and classical-like EDS and evidence of tissue fragility as seen in individuals with vEDS. CONCLUSION: The clinical data demonstrate the overlap between the different EDS subtypes and underline the importance of next-generation sequencing gene panel analysis. The three different Glu>Lys variants point toward a new variant type in COL3A1 causative of vEDS, which has consistent clinical features. This is important knowledge for COL3A1 variant interpretation. Further follow-up data are required to establish the severity of tissue fragility complications compared with patients with other recognized molecular causes of vEDS.
Assuntos
Colágeno Tipo III/genética , Síndrome de Ehlers-Danlos/genética , Anormalidades da Pele/genética , Adulto , Idoso , Síndrome de Ehlers-Danlos/classificação , Síndrome de Ehlers-Danlos/patologia , Feminino , Ácido Glutâmico/genética , Glicina/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lisina/genética , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Fenótipo , Anormalidades da Pele/patologiaRESUMO
Skeletal dysplasias are a clinically and genetically heterogeneous group of bone and cartilage disorders. Whilst >450 skeletal dysplasias have been reported, 30% are genetically uncharacterized. We report two Irish Traveller families with a previously undescribed lethal skeletal dysplasia characterized by fetal akinesia, shortening of all long bones, multiple contractures, rib anomalies, thoracic dysplasia, pulmonary hypoplasia and protruding abdomen. Single nucleotide polymorphism homozygosity mapping and whole exome sequencing identified a novel homozygous stop-gain mutation in NEK9 (c.1489C>T; p.Arg497*) as the cause of this disorder. NEK9 encodes a never in mitosis gene A-related kinase involved in regulating spindle organization, chromosome alignment, cytokinesis and cell cycle progression. This is the first disorder to be associated with NEK9 in humans. Analysis of NEK9 protein expression and localization in patient fibroblasts showed complete loss of full-length NEK9 (107 kDa). Functional characterization of patient fibroblasts showed a significant reduction in cell proliferation and a delay in cell cycle progression. We also provide evidence to support possible ciliary associations for NEK9. Firstly, patient fibroblasts displayed a significant reduction in cilia number and length. Secondly, we show that the NEK9 orthologue in Caenorhabditis elegans, nekl-1, is almost exclusively expressed in a subset of ciliated cells, a strong indicator of cilia-related functions. In summary, we report the clinical and molecular characterization of a lethal skeletal dysplasia caused by NEK9 mutation and suggest that this disorder may represent a novel ciliopathy.
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Ciclo Celular/fisiologia , Cílios/patologia , Genes Recessivos/genética , Mutação/genética , Quinases Relacionadas a NIMA/genética , Osteocondrodisplasias/etiologia , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Células Cultivadas , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Lactente , Masculino , Osteocondrodisplasias/patologia , Linhagem , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
PurposeIn 2012 we reported in six individuals a clinical condition almost indistinguishable from PLOD1-kyphoscoliotic Ehlers-Danlos syndrome (PLOD1-kEDS), caused by biallelic mutations in FKBP14, and characterized by progressive kyphoscoliosis, myopathy, and hearing loss in addition to connective tissue abnormalities such as joint hypermobility and hyperelastic skin. FKBP14 is an ER-resident protein belonging to the family of FK506-binding peptidyl-prolyl cis-trans isomerases (PPIases); it catalyzes the folding of type III collagen and interacts with type III, type VI, and type X collagens. Only nine affected individuals have been reported to date.MethodsWe report on a cohort of 17 individuals with FKBP14-kEDS and the follow-up of three previously reported patients, and provide an extensive overview of the disorder and its natural history based on clinical, biochemical, and molecular genetics data.ResultsBased on the frequency of the clinical features of 23 patients from the present and previous cohorts, we define major and minor features of FKBP14-kEDS. We show that myopathy is confirmed by histology and muscle imaging only in some patients, and that hearing impairment is predominantly sensorineural and may not be present in all individuals.ConclusionOur data further support the extensive clinical overlap with PLOD1-kEDS and show that vascular complications are rare manifestations of FKBP14-kEDS.
Assuntos
Alelos , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/genética , Estudos de Associação Genética , Mutação , Peptidilprolil Isomerase/genética , Fenótipo , Criança , Pré-Escolar , Mapeamento Cromossômico , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Humanos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , MasculinoRESUMO
Variants in the Protein Kinase CK2 alpha subunit, encoding the CSNK2A1 gene, have previously been reported in children with an intellectual disability and dysmorphic facial features syndrome: now termed the Okur-Chung neurodevelopmental syndrome. More recently, through trio-based exome sequencing undertaken by the Deciphering Developmental Disorders Study (DDD study), a further 11 children with de novo CSNK2A1 variants have been identified. We have undertaken detailed phenotyping of these patients. Consistent with previously reported patients, patients in this series had apparent intellectual disability, swallowing difficulties, and hypotonia. While there are some shared facial characteristics, the gestalt is neither consistent nor readily recognized. Congenital heart abnormalities were identified in nearly 30% of the patients, representing a newly recognized CSNK2A1 clinical association. Based upon the clinical findings from this study and the previously reported patients, we suggest an initial approach to the management of patients with this recently described intellectual disability syndrome.
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Mutação , Transtornos do Neurodesenvolvimento/diagnóstico , Transtornos do Neurodesenvolvimento/genética , Fenótipo , Alelos , Motivos de Aminoácidos , Sequência de Aminoácidos , Substituição de Aminoácidos , Caseína Quinase II/química , Caseína Quinase II/genética , Criança , Éxons , Fácies , Feminino , Humanos , Masculino , Ligação Proteica , Domínios e Motivos de Interação entre ProteínasRESUMO
The Ehlers-Danlos syndromes comprise a clinically and genetically heterogeneous group of heritable connective tissue disorders, which are characterized by joint hypermobility, skin hyperextensibility, and tissue friability. In the Villefranche Nosology, six subtypes were recognized: The classical, hypermobile, vascular, kyphoscoliotic, arthrochalasis, and dermatosparaxis subtypes of EDS. Except for the hypermobile subtype, defects had been identified in fibrillar collagens or in collagen-modifying enzymes. Since 1997, a whole spectrum of novel, clinically overlapping, rare EDS-variants have been delineated and genetic defects have been identified in an array of other extracellular matrix genes. Advances in molecular testing have made it possible to now identify the causative mutation for many patients presenting these phenotypes. The aim of this literature review is to summarize the current knowledge on the rare EDS subtypes and highlight areas for future research. © 2017 Wiley Periodicals, Inc.
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Síndrome de Ehlers-Danlos/classificação , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/genética , Matriz Extracelular/genética , Heterogeneidade Genética , Humanos , Técnicas de Diagnóstico Molecular/tendências , MutaçãoRESUMO
The Ehlers-Danlos syndromes (EDS) are a clinically and genetically heterogeneous group of heritable connective tissue disorders (HCTDs) characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. Over the past two decades, the Villefranche Nosology, which delineated six subtypes, has been widely used as the standard for clinical diagnosis of EDS. For most of these subtypes, mutations had been identified in collagen-encoding genes, or in genes encoding collagen-modifying enzymes. Since its publication in 1998, a whole spectrum of novel EDS subtypes has been described, and mutations have been identified in an array of novel genes. The International EDS Consortium proposes a revised EDS classification, which recognizes 13 subtypes. For each of the subtypes, we propose a set of clinical criteria that are suggestive for the diagnosis. However, in view of the vast genetic heterogeneity and phenotypic variability of the EDS subtypes, and the clinical overlap between EDS subtypes, but also with other HCTDs, the definite diagnosis of all EDS subtypes, except for the hypermobile type, relies on molecular confirmation with identification of (a) causative genetic variant(s). We also revised the clinical criteria for hypermobile EDS in order to allow for a better distinction from other joint hypermobility disorders. To satisfy research needs, we also propose a pathogenetic scheme, that regroups EDS subtypes for which the causative proteins function within the same pathway. We hope that the revised International EDS Classification will serve as a new standard for the diagnosis of EDS and will provide a framework for future research purposes. © 2017 Wiley Periodicals, Inc.
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Síndrome de Ehlers-Danlos/classificação , Guias de Prática Clínica como Assunto , Colágeno/genética , Doenças do Tecido Conjuntivo/genética , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/genética , Heterogeneidade Genética , Humanos , MutaçãoRESUMO
Short stature, auditory canal atresia, mandibular hypoplasia, and skeletal abnormalities (SAMS) has been reported previously to be a rare, autosomal-recessive developmental disorder with other, unique rhizomelic skeletal anomalies. These include bilateral humeral hypoplasia, humeroscapular synostosis, pelvic abnormalities, and proximal defects of the femora. To identify the genetic basis of SAMS, we used molecular karyotyping and whole-exome sequencing (WES) to study small, unrelated families. Filtering of variants from the WES data included segregation analysis followed by comparison of in-house exomes. We identified a homozygous 306 kb microdeletion and homozygous predicted null mutations of GSC, encoding Goosecoid homeobox protein, a paired-like homeodomain transcription factor. This confirms that SAMS is a human malformation syndrome resulting from GSC mutations. Previously, Goosecoid has been shown to be a determinant at the Xenopus gastrula organizer region and a segment-polarity determinant in Drosophila. In the present report, we present data on Goosecoid protein localization in staged mouse embryos. These data and the SAMS clinical phenotype both suggest that Goosecoid is a downstream effector of the regulatory networks that define neural-crest cell-fate specification and subsequent mesoderm cell lineages in mammals, particularly during shoulder and hip formation. Our findings confirm that Goosecoid has an essential role in human craniofacial and joint development and suggest that Goosecoid is an essential regulator of mesodermal patterning in mammals and that it has specific functions in neural crest cell derivatives.
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Anormalidades Múltiplas/genética , Osso e Ossos/anormalidades , Nanismo/genética , Meato Acústico Externo/anormalidades , Proteína Goosecoid/genética , Mandíbula/anormalidades , Mutação , Anormalidades Múltiplas/diagnóstico , Adulto , Animais , Criança , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Homozigoto , Humanos , Masculino , Camundongos , Linhagem , Fenótipo , Síndrome , Adulto JovemRESUMO
PURPOSE: Ehlers-Danlos syndrome (EDS) comprises a group of overlapping hereditary disorders of connective tissue with significant morbidity and mortality, including major vascular complications. We sought to identify the diagnostic utility of a next-generation sequencing (NGS) panel in a mixed EDS cohort. METHODS: We developed and applied PCR-based NGS assays for targeted, unbiased sequencing of 12 collagen and aortopathy genes to a cohort of 177 unrelated EDS patients. Variants were scored blind to previous genetic testing and then compared with results of previous Sanger sequencing. RESULTS: Twenty-eight pathogenic variants in COL5A1/2, COL3A1, FBN1, and COL1A1 and four likely pathogenic variants in COL1A1, TGFBR1/2, and SMAD3 were identified by the NGS assays. These included all previously detected single-nucleotide and other short pathogenic variants in these genes, and seven newly detected pathogenic or likely pathogenic variants leading to clinically significant diagnostic revisions. Twenty-two variants of uncertain significance were identified, seven of which were in aortopathy genes and required clinical follow-up. CONCLUSION: Unbiased NGS-based sequencing made new molecular diagnoses outside the expected EDS genotype-phenotype relationship and identified previously undetected clinically actionable variants in aortopathy susceptibility genes. These data may be of value in guiding future clinical pathways for genetic diagnosis in EDS.Genet Med 18 11, 1119-1127.
Assuntos
Colágeno/genética , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Síndrome de Ehlers-Danlos/fisiopatologia , Feminino , Testes Genéticos , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/genética , Patologia Molecular/métodos , Fenótipo , Proteínas Serina-Treonina Quinases/genética , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/genética , Adulto JovemRESUMO
Vascular Ehlers-Danlos syndrome (vEDS) is a heritable disorder of connective tissue caused by pathological variants in the COL3A1 gene, which encodes the α1 chain of type III collagen. Type III collagen is a major component of skin, arterial walls, and the gastrointestinal tract. Collagen III protein deficiency manifests as an increased risk of rupture, perforation, and dissection of these structures. The most disruptive gene variants affect the collagen helix via glycine substitutions or splice donor site mutations. The C-propeptide region of COL3A1 includes exons 49-52 and has a crucial role in initiating the C-terminal assembly of procollagen monomers in the early stages of collagen biosynthesis. Nineteen COL3A1 variants have previously been reported in these exons, of which four were associated with a severe vEDS phenotype. We identified two novel C-propeptide missense variants; p.Pro1440Leu, p.Arg1432Leu, and a non-stop mutation, c.4400A > T, p. (*1467Leuext*45). These variants produce variable phenotypes ranging from obvious acrogeria to classical or hypermobile EDS. A previously reported variant p.Lys1313Arg is of unknown clinical significance but likely benign, based on this study. Assigning disease pathogenicity remains complex, clinical phenotyping and crystal structure evidence being crucial. We briefly compare reported phenotypes for patients with missense variants in the C-propeptide domain for other human collagen disorders including COL1A1 and COL1A2 (osteogenesis imperfecta).
Assuntos
Colágeno Tipo III/genética , Fragmentos de Peptídeos/genética , Adulto , Colágeno Tipo III/química , Cristalografia por Raios X , Síndrome de Ehlers-Danlos/genética , Éxons , Feminino , Humanos , Masculino , Fragmentos de Peptídeos/química , Conformação ProteicaRESUMO
Introduction: Vascular Ehlers-Danlos syndrome (vEDS) is an autosomal dominant inherited connective tissue condition, characterized by generalized tissue fragility with an increased risk of arterial dissection and hollow organ rupture. In women with vEDS, pregnancy and childbirth carry significant risks of both morbidity and mortality. The Human Fertilisation and Embryology Authority has approved vEDS for pre-implantation genetic diagnosis (PGD), given the potential for life-limiting complications. PGD avoids implantation of embryos that are affected by specific disorders by carrying out genetic testing (either for a familial variant or whole gene) and selecting unaffected embryos prior to implantation. Case: We present an essential clinical update to the only published clinical case of a woman with vEDS undergoing PGD with surrogacy, initially through stimulated in vitro fertilization (IVF) and in vitro maturation (IVM) and subsequently through natural IVF. Discussion: In our experience, a subset of women with vEDS do wish to have biological, unaffected children through PGD despite being aware of the risks of pregnancy and delivery. Given the clinical heterogeneity in vEDS, these women could be considered on a case-by-case basis for PGD. Controlled studies with comprehensive patient monitoring evaluating the safety of PGD are essential to equitable healthcare provision.