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1.
Genet Med ; 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31316167

RESUMO

PURPOSE: Congenital contractural arachnodactyly (CCA) is an autosomal dominant connective tissue disorder manifesting joint contractures, arachnodactyly, crumpled ears, and kyphoscoliosis as main features. Due to its rarity, rather aspecific clinical presentation, and overlap with other conditions including Marfan syndrome, the diagnosis is challenging, but important for prognosis and clinical management. CCA is caused by pathogenic variants in FBN2, encoding fibrillin-2, but locus heterogeneity has been suggested. We designed a clinical scoring system and diagnostic criteria to support the diagnostic process and guide molecular genetic testing. METHODS: In this retrospective study, we assessed 167 probands referred for FBN2 analysis and classified them into a FBN2-positive (n = 44) and FBN2-negative group (n = 123) following molecular analysis. We developed a 20-point weighted clinical scoring system based on the prevalence of ten main clinical characteristics of CCA in both groups. RESULTS: The total score was significantly different between the groups (P < 0.001) and was indicative for classifying patients into unlikely CCA (total score <7) and likely CCA (total score ≥7) groups. CONCLUSIONS: Our clinical score is helpful for clinical guidance for patients suspected to have CCA, and provides a quantitative tool for phenotyping in research settings.

2.
Hum Mol Genet ; 28(11): 1801-1809, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30657919

RESUMO

The cyclic adenosine monophosphate responsive element binding protein 3-like 1 (CREB3L1) gene codes for the endoplasmic reticulum stress transducer old astrocyte specifically induced substance (OASIS), which has an important role in osteoblast differentiation during bone development. Deficiency of OASIS is linked to a severe form of autosomal recessive osteogenesis imperfecta (OI), but only few patients have been reported. We identified the first homozygous pathogenic missense variant [p.(Ala304Val)] in a patient with lethal OI, which is located within the highly conserved basic leucine zipper domain, four amino acids upstream of the DNA binding domain. In vitro structural modeling and luciferase assays demonstrate that this missense variant affects a critical residue in this functional domain, thereby decreasing the type I collagen transcriptional binding ability. In addition, overexpression of the mutant OASIS protein leads to decreased transcription of the SEC23A and SEC24D genes, which code for components of the coat protein complex type II (COPII), and aberrant OASIS signaling also results in decreased protein levels of SEC24D. Our findings therefore provide additional proof of the potential involvement of the COPII secretory complex in the context of bone-associated disease.

3.
Hum Mol Genet ; 28(11): 1853-1864, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30668708

RESUMO

The Ehlers-Danlos syndromes (EDSs) are a clinically and molecularly diverse group of heritable connective tissue disorders caused by defects in a wide range of genes. Recently, bi-allelic loss-of-function mutations in the adipocyte enhancer-binding protein 1 (AEBP1) gene were reported in three families with an autosomal recessive EDS-like condition characterized by thin and hyperextensible skin, poor wound healing with prominent atrophic scarring, joint hypermobility and osteoporosis. Using whole exome sequencing, we identified novel bi-allelic AEBP1 variants in two unrelated adult patients, previously diagnosed with an undefined EDS type, which shows important clinical resemblance to several other EDS subtypes. Our patients present with similar cutaneous and musculoskeletal features as the previously reported patients. They also show unreported clinical features, including pectus deformity, premature aged appearance, sparse and frizzled hair, fatigue and pain. AEBP1 is ubiquitously expressed and encodes the secreted aortic carboxypeptidase-like protein (ACLP) that can bind fibrillar collagens and assist in collagen polymerization. Transmission electron microscopy studies on the patients' skin biopsies show ultrastructural alterations in collagen fibril diameter and appearance, underscoring an important role for ACLP in collagen fibril organization. This report further expands the clinical, molecular and ultrastructural spectrum associated with AEBP1 defects and highlights the complex and variable phenotype associated with this new EDS variant.

4.
Sci Rep ; 8(1): 15845, 2018 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-30374100

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

5.
Dis Model Mech ; 11(10)2018 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-30355591

RESUMO

Targeted genome editing by CRISPR/Cas9 is extremely well fitted to generate gene disruptions, although precise sequence replacement by CRISPR/Cas9-mediated homology-directed repair (HDR) suffers from low efficiency, impeding its use for high-throughput knock-in disease modeling. In this study, we used next-generation sequencing (NGS) analysis to determine the efficiency and reliability of CRISPR/Cas9-mediated HDR using several types of single-stranded oligodeoxynucleotide (ssODN) repair templates for the introduction of disease-relevant point mutations in the zebrafish genome. Our results suggest that HDR rates are strongly determined by repair-template composition, with the most influential factor being homology-arm length. However, we found that repair using ssODNs does not only lead to precise sequence replacement but also induces integration of repair-template fragments at the Cas9 cut site. We observed that error-free repair occurs at a relatively constant rate of 1-4% when using different repair templates, which was sufficient for transmission of point mutations to the F1 generation. On the other hand, erroneous repair mainly accounts for the variability in repair rate between the different repair templates. To further improve error-free HDR rates, elucidating the mechanism behind this erroneous repair is essential. We show that the error-prone nature of ssODN-mediated repair, believed to act via synthesis-dependent strand annealing (SDSA), is most likely due to DNA synthesis errors. In conclusion, caution is warranted when using ssODNs for the generation of knock-in models or for therapeutic applications. We recommend the application of in-depth NGS analysis to examine both the efficiency and error-free nature of HDR events.This article has an associated First Person interview with the first author of the paper.

7.
Proc Natl Acad Sci U S A ; 115(34): E8037-E8046, 2018 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-30082390

RESUMO

The type I collagenopathies are a group of heterogeneous connective tissue disorders, that are caused by mutations in the genes encoding type I collagen and include specific forms of osteogenesis imperfecta (OI) and the Ehlers-Danlos syndrome (EDS). These disorders present with a broad disease spectrum and large clinical variability of which the underlying genetic basis is still poorly understood. In this study, we systematically analyzed skeletal phenotypes in a large set of zebrafish, with diverse mutations in the genes encoding type I collagen, representing different genetic forms of human OI, and a zebrafish model resembling human EDS, which harbors a number of soft connective tissues defects, typical of EDS. Furthermore, we provide insight into how zebrafish and human type I collagen are compositionally and functionally related, which is relevant in the interpretation of human type I collagen-related disease models. Our studies reveal a high degree of intergenotype variability in phenotypic expressivity that closely correlates with associated OI severity. Furthermore, we demonstrate the potential for select mutations to give rise to phenotypic variability, mirroring the clinical variability associated with human disease pathology. Therefore, our work suggests the future potential for zebrafish to aid in identifying unknown genetic modifiers and mechanisms underlying the phenotypic variability in OI and related disorders. This will improve diagnostic strategies and enable the discovery of new targetable pathways for pharmacological intervention.


Assuntos
Colágeno Tipo I , Modelos Animais de Doenças , Síndrome de Ehlers-Danlos , Osteogênese Imperfeita , Peixe-Zebra , Animais , Animais Geneticamente Modificados , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Síndrome de Ehlers-Danlos/genética , Síndrome de Ehlers-Danlos/metabolismo , Síndrome de Ehlers-Danlos/patologia , Humanos , Osteogênese Imperfeita/genética , Osteogênese Imperfeita/metabolismo , Osteogênese Imperfeita/patologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
8.
Circ Genom Precis Med ; 11(6): e002039, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29875124

RESUMO

BACKGROUND: The introduction of next-generation sequencing techniques has substantially increased the identification of new genetic variants and hence the necessity of accurate variant interpretation. In 2015, the American College of Medical Genetics and Genomics and the Association for Molecular Pathology proposed new variant interpretation guidelines. Gene-specific characteristics were, however, not considered, sometimes leading to inconsistent variant interpretation. METHODS: To allow a more uniform interpretation of variants in the FBN1 (fibrillin-1) gene, causing Marfan syndrome, we tailored these guidelines to this gene and disease. We adapted 15 of the 28 general criteria and classified 713 FBN1 variants previously identified in our laboratory as causal mutation or variant of uncertain significance according to these adapted guidelines. We then compared the agreement between previous methods and the adapted American College of Medical Genetics and Genomics and the Association for Molecular Pathology criteria. RESULTS: Agreement between the methods was 86.4% (K-alpha, 0.6). Application of the tailored guidelines resulted in an increased number of variants of uncertain significance (14.5% to 24.2%). Of the 85 variants that were downscaled to likely benign or variant of uncertain significance, 59.7% were missense variants outside a well-established functional site. Available clinical- or segregation data, necessary to further classify these types of variants, were in many cases insufficient to aid the classification. CONCLUSIONS: Our study shows that classification of variants remains challenging and may change over time. Currently, a higher level of evidence is necessary to classify a variant as pathogenic. Gene-specific guidelines may be useful to allow a more precise and uniform interpretation of the variants to accurately support clinical decision-making.

9.
Brain Pathol ; 2018 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-29722917

RESUMO

Ischemic stroke causes a high mortality and morbidity worldwide. It results from a complex interplay of incompletely known environmental and genetic risk factors. We investigated the ABCC6 gene as a candidate risk factor for ischemic stroke because of the increased ischemic stroke incidence in the autosomal recessive disorder pseudoxanthoma elasticum, caused by biallelic pathogenic ABCC6 variants, the higher cardiovascular risk in heterozygous carriers and the established role of ABCC6 dysfunction in myocardial ischemia. We established segregation of a known pathogenic ABCC6 variant (p.(Arg1314Gln)) in 11/19 family members of an ischemic stroke patient in a large multigenerational family suffering from ischemic stroke and/or cardiovascular disease at a relatively young age. In an independent case-control study in 424 ischemic stroke patients and 250 healthy controls, pathogenic ABCC6 variants were 4.9 times more frequent (p = 0.036; 95% confidence interval 1.11-21.33) in the ischemic stroke patient cohort. To study cellular consequences of ABCC6 deficiency in the brain, immunostaining of brain sections in Abcc6-deficient mice and wildtype controls were performed. An upregulation of Bmp4 and Eng and a downregulation of Alk2 was identified in Abcc6-/- mice, suggesting an increase in apoptosis and angiogenesis. As both of these processes are induced in ischemia, we propose that a pro-ischemic state may explain the higher risk to suffer from ischemic stroke in patients carrying a pathogenic ABCC6 variant, as this may lower the threshold to develop acute ischemic events in these patients. In conclusion, this study identified heterozygous ABCC6 variants as a risk factor for ischemic stroke. Further, dysregulation of Bmp (Bmp4, Alk2) and Tgfß (Eng) signaling in the brain of Abcc6-/- mice could lead to a pro-ischemic state, lowering the threshold to develop acute ischemic events. These data demonstrate the importance of a molecular analysis of the ABCC6 gene in patients diagnosed with cryptogenic ischemic stroke. This article is protected by copyright. All rights reserved.

10.
Matrix Biol ; 70: 72-83, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29551664

RESUMO

Type III collagen is a major fibrillar collagen consisting of three identical α1(III)-chains that is particularly present in tissues exhibiting elastic properties, such as the skin and the arterial wall. Heterozygous mutations in the COL3A1 gene result in vascular Ehlers-Danlos syndrome (vEDS), a severe, life-threatening disorder, characterized by thin, translucent skin and propensity to arterial, intestinal and uterine rupture. Most human vEDS cases result from a missense mutation substituting a crucial glycine residue in the triple helical domain of the α1(III)-chains. The mechanisms by which these mutant type III collagen molecules cause dermal and vascular fragility are not well understood. We generated a transgenic mouse line expressing mutant type III collagen, containing a typical helical glycine substitution (p.(Gly182Ser)). This Col3a1Tg-G182S mouse line displays a phenotype recapitulating characteristics of human vEDS patients with signs of dermal and vascular fragility. The Col3a1Tg-G182S mice develop severe transdermal skin wounds, resulting in early demise at 13-14weeks of age. We found that this phenotype was associated with a reduced total collagen content and an abnormal collagen III:I ratio, leading to the production of severely malformed collagen fibrils in the extracellular matrix of dermal and arterial tissues. These results indicate that expression of the glycine substitution in the α1(III)-chain disturbs formation of heterotypic type III:I collagen fibrils, and thereby demonstrate a key role for type III collagen in collagen fibrillogenesis in dermal and arterial tissues.

11.
Genet Med ; 20(10): 1236-1245, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29323665

RESUMO

PURPOSE: We delineate the clinical spectrum and describe the histology in arterial tortuosity syndrome (ATS), a rare connective tissue disorder characterized by tortuosity of the large and medium-sized arteries, caused by mutations in SLC2A10. METHODS: We retrospectively characterized 40 novel ATS families (50 patients) and reviewed the 52 previously reported patients. We performed histology and electron microscopy (EM) on skin and vascular biopsies and evaluated TGF-ß signaling with immunohistochemistry for pSMAD2 and CTGF. RESULTS: Stenoses, tortuosity, and aneurysm formation are widespread occurrences. Severe but rare vascular complications include early and aggressive aortic root aneurysms, neonatal intracranial bleeding, ischemic stroke, and gastric perforation. Thus far, no reports unequivocally document vascular dissections or ruptures. Of note, diaphragmatic hernia and infant respiratory distress syndrome (IRDS) are frequently observed. Skin and vascular biopsies show fragmented elastic fibers (EF) and increased collagen deposition. EM of skin EF shows a fragmented elastin core and a peripheral mantle of microfibrils of random directionality. Skin and end-stage diseased vascular tissue do not indicate increased TGF-ß signaling. CONCLUSION: Our findings warrant attention for IRDS and diaphragmatic hernia, close monitoring of the aortic root early in life, and extensive vascular imaging afterwards. EM on skin biopsies shows disease-specific abnormalities.

12.
Mol Genet Genomic Med ; 6(1): 15-26, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29150909

RESUMO

BACKGROUND: Osteogenesis imperfecta (OI) is a heterogeneous hereditary connective tissue disorder clinically hallmarked by increased susceptibility to bone fractures. METHODS: We analyzed a cohort of 77 diagnosed OI patients from 49 unrelated Palestinian families. Next-generation sequencing technology was used to screen a panel of known OI genes. RESULTS: In 41 probands, we identified 28 different disease-causing variants of 9 different known OI genes. Eleven of the variants are novel. Ten of the 28 variants are located in COL1A1, five in COL1A2, three in BMP1, three in FKBP10, two in TMEM38B, two in P3H1, and one each in CRTAP, SERPINF1, and SERPINH1. The absence of disease-causing variants in the remaining eight probands suggests further genetic heterogeneity in OI. In general, most OI patients (90%) harbor mainly variants in type I collagen resulting in an autosomal dominant inheritance pattern. However, in our cohort almost 61% (25/41) were affected with autosomal recessive OI. Moreover, we document a 21-kb genomic deletion in the TMEM38B gene identified in 29% (12/41) of the tested probands, making it the most frequent OI-causing variant in the Palestinian population. CONCLUSION: This is the first genetic screening of an OI cohort from the Palestinian population. Our data are important for genetic counseling of OI patients and families in highly consanguineous populations.


Assuntos
Árabes/genética , Osteogênese Imperfeita/genética , Adulto , Calcificação Fisiológica/genética , Colágeno Tipo I/genética , Consanguinidade , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Família , Feminino , Genes Recessivos , Humanos , Canais Iônicos/genética , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Deleção de Sequência
13.
Toxicol Sci ; 163(2): 409-419, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28329870

RESUMO

A number of drugs can cause precipitates within renal tubules leading to crystal nephropathy. Crystal nephropathy is usually an exposure-related finding and is not uncommon in preclinical studies, where high doses are tested. An understanding of the nature of precipitates is important for human risk assessment and further development. Our aim was to investigate the ability of various imaging techniques to detect the presence of drugs or metabolites in renal crystals. We applied matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) imaging, Raman and infrared microspectroscopy, scanning electron microscopy coupled with energy dispersive X-ray (SEM/EDX) spectroscopy and standard histopathology to cases of drug-induced crystal nephropathy, induced in rodents and primates by 4 compounds. MALDI-FTICR MS imaging enabled the identification of the drug-related crystal content in all 4 cases of nephropathy, without reference material and with high accuracy. Crystals were composed of unchanged parent drug and/or metabolites. Similar results were obtained using Raman and infrared microspectroscopy for 2 compounds. In the absence of reference standards of metabolites, Raman and infrared microspectroscopy showed that the crystals consisted of components similar, but not identical, to the administered drug for the other compounds, a limitation for these techniques. SEM/EDX showed which counter ions were colocalized with the identified drug-related material, complementing the MALDI-FTICR MS findings. Therefore, we recommend MALDI-FTICR MS as a first-line methodology to characterize crystal nephropathies. Raman and infrared microspectroscopy may be useful when MALDI-FTICR MS imaging cannot be applied. SEM/EDX could be considered as a complementary technology.

14.
BMC Med Ethics ; 18(1): 46, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28764782

RESUMO

BACKGROUND: Carrier screening is generally performed with the aim of identifying healthy couples at risk of having a child affected with a monogenic disorder to provide them with reproductive options. Expanded carrier screening (ECS), which provides the opportunity for multiple conditions to be screened in one test, offers a more cost-effective and comprehensive option than screening for single disorders. However, implementation of ECS at a population level would have implications for genetic counseling practice. METHODS: We conducted semi-structured interviews with sixteen European clinical and molecular geneticists with expertise in carrier screening to explore their views on the implementation of ECS in the clinical setting. RESULTS: Using inductive content analysis, we identified content categories relevant to the pre- and post-test settings. Participants believed ECS would ideally be targeted at couples before pregnancy. There was some disagreement regarding the acceptability of performing ECS in individuals, with several participants actively opposing individual-based screening. In addition, participants discussed the importance of ensuring informed and voluntary participation in ECS, recommending measures to minimize external pressure on prospective parents to undergo testing. A need for adequate counseling to foster informed, autonomous reproductive decision-making and provide support for couples found to be at risk was emphasized. CONCLUSIONS: Practical challenges in optimizing pre-test education and post-test counseling should not be underestimated and they should be carefully addressed before implementing ECS in the clinical setting.


Assuntos
Atitude do Pessoal de Saúde , Aconselhamento , Triagem de Portadores Genéticos/ética , Aconselhamento Genético , Pessoal de Saúde , Programas de Rastreamento/ética , Reprodução , Acesso à Informação/ética , Tomada de Decisões/ética , Europa (Continente) , Características da Família , Feminino , Testes Genéticos , Humanos , Consentimento Livre e Esclarecido , Seleção de Pacientes/ética , Gravidez , Estudos Prospectivos
15.
Acta Cardiol ; 72(6): 616-624, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28657492

RESUMO

BACKGROUND: Marfan syndrome (MFS) is a multisystemic hereditary connective tissue disease. Aortic root aneurysms and dissections are the most common and life-threatening cardiovascular disorders affecting these patients. Other cardiac manifestations include mitral valve prolapse, ventricular dysfunction and arrhythmias. Medical treatment of cardiovascular features is ultimately aimed at slowing down aortic root growth rate and preventing dissection. Losartan has been proposed as a new therapeutic tool for this purpose. To which extent losartan affects cardiac function has not been studied previously. METHODS: We designed a prospective, double-blind, randomized placebo-controlled trial to evaluate the effect of losartan added to beta-blocker therapy on aortic growth and ventricular function in patients with MFS. Secondary outcomes were aortic dissection, prophylactic aortic surgery and death. RESULTS: Twenty-two patients were enrolled in the trial. There was a mild and similar increase in the aortic root during the 3 years of follow-up in both groups (median 1 mm, IQR [-1-1.5] and 1 mm, IQR [-0.25-1] in the losartan and placebo group, respectively, p = 1). Diastolic and systolic ventricular function was normal at baseline in both groups and remained stable during the study. One patient in the placebo group presented a subclavian artery dissection during follow-up. CONCLUSION: Losartan on top of beta-blocker therapy has no additional effect on aortic growth or on cardiac function in patients with MFS. Our results are underpowered but are in line with the result from other groups. In order to have a better insight on whether a group of patients could benefit more from losartan therapy, the outcome of an on-going meta-analysis should be awaited.

16.
Am J Med Genet C Semin Med Genet ; 175(1): 8-26, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28306229

RESUMO

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.


Assuntos
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 , Mutação
17.
Am J Med Genet A ; 173(4): 1047-1050, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28261977

RESUMO

Type I collagen is the predominant protein of connective tissues such as skin and bone. Mutations in the type I collagen genes (COL1A1 and COL1A2) mainly cause osteogenesis imperfecta (OI). We describe a patient with clinical signs of Ehlers-Danlos syndrome (EDS), including fragile skin, easy bruising, recurrent luxations, and fractures resembling mild OI. Biochemical collagen analysis of the patients' dermal fibroblasts showed faint overmodification of the type I collagen bands, a finding specific for structural defects in type I collagen. Bidirectional Sanger sequencing detected an in-frame deletion in exon 44 of COL1A1 (c.3150_3158del), resulting in the deletion of three amino acids (p.Ala1053_Gly1055del) in the collagen triple helix. This COL1A1 mutation was hitherto identified in four probands with lethal OI, and never in EDS patients. As the peaks on the electropherogram corresponding to the mutant allele were decreased in intensity, we performed next generation sequencing of COL1A1 to study mosaicism in skin and blood. While approximately 9% of the reads originating from fibroblast gDNA harbored the COL1A1 deletion, the deletion was not detected in gDNA from blood. Most likely, the mild clinical symptoms observed in our patient can be explained by the mosaic state of the mutation.


Assuntos
Colágeno Tipo I/genética , Síndrome de Ehlers-Danlos/genética , Mosaicismo , Mutação , Osteogênese Imperfeita/genética , Sequência de Bases , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Síndrome de Ehlers-Danlos/diagnóstico , Síndrome de Ehlers-Danlos/patologia , Éxons , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Especificidade de Órgãos , Osteogênese Imperfeita/diagnóstico , Osteogênese Imperfeita/patologia , Pele/metabolismo , Pele/patologia , Adulto Jovem
18.
Am J Hum Genet ; 100(2): 216-227, 2017 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-28065471

RESUMO

Defects of the V-type proton (H+) ATPase (V-ATPase) impair acidification and intracellular trafficking of membrane-enclosed compartments, including secretory granules, endosomes, and lysosomes. Whole-exome sequencing in five families affected by mild to severe cutis laxa, dysmorphic facial features, and cardiopulmonary involvement identified biallelic missense mutations in ATP6V1E1 and ATP6V1A, which encode the E1 and A subunits, respectively, of the V1 domain of the heteromultimeric V-ATPase complex. Structural modeling indicated that all substitutions affect critical residues and inter- or intrasubunit interactions. Furthermore, complexome profiling, a method combining blue-native gel electrophoresis and liquid chromatography tandem mass spectrometry, showed that they disturb either the assembly or the stability of the V-ATPase complex. Protein glycosylation was variably affected. Abnormal vesicular trafficking was evidenced by delayed retrograde transport after brefeldin A treatment and abnormal swelling and fragmentation of the Golgi apparatus. In addition to showing reduced and fragmented elastic fibers, the histopathological hallmark of cutis laxa, transmission electron microscopy of the dermis also showed pronounced changes in the structure and organization of the collagen fibers. Our findings expand the clinical and molecular spectrum of metabolic cutis laxa syndromes and further link defective extracellular matrix assembly to faulty protein processing and cellular trafficking caused by genetic defects in the V-ATPase complex.


Assuntos
Cútis Laxa/genética , Mutação de Sentido Incorreto , ATPases Vacuolares Próton-Translocadoras/genética , Adolescente , Alelos , Sequência de Aminoácidos , Estudos de Casos e Controles , Criança , Feminino , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Estudo de Associação Genômica Ampla , Glicosilação , Complexo de Golgi/metabolismo , Humanos , Lactente , Recém-Nascido , Masculino , Linhagem , Conformação Proteica , Transporte Proteico , Espectrometria de Massas em Tandem
19.
J Obstet Gynecol Neonatal Nurs ; 46(1): 63-71, 2017 Jan - Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27875676

RESUMO

OBJECTIVE: To explore attitudes of clinical and molecular geneticists about the implementation of multi-disease or expanded carrier screening (ECS) for monogenic recessive disorders. DESIGN: Qualitative; semistructured interviews. SETTING: In person or via Skype. Interviews were audiorecorded and transcribed verbatim. PARTICIPANTS: European clinical and molecular geneticists with expertise in carrier screening (N = 16). METHODS: Inductive content analysis was used to identify common content categories in the data. RESULTS: Participants recognized important benefits of ECS, but they also identified major challenges, including limited benefit of ECS for most couples in the general population, lack of knowledge on carrier screening among nongenetic health care providers and the general public, potential negative implications of ECS for society, and limited economic resources. Participants favored an evidence-based approach to the implementation of population-wide ECS and were reluctant to actively offer ECS in the absence of demonstrable benefits. However, there was a consensus among the participants that ECS should be made available to couples who request the test. In addition, they believed ECS could be routinely offered to all people who use assisted reproduction. CONCLUSION: Although a limited ECS offer is practical, it also raises concerns over equality in access to screening. A comprehensive risk-benefit analysis is needed to determine the desirability of systematic population-wide ECS.


Assuntos
Atitude do Pessoal de Saúde , Triagem de Portadores Genéticos/normas , Aconselhamento Genético/normas , Testes Genéticos/normas , Europa (Continente) , Grupo com Ancestrais do Continente Europeu , Feminino , Humanos
20.
Eur J Med Genet ; 59(10): 502-6, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27633570

RESUMO

There are no published reports of patients harboring microdeletions involving the 7p22.1 region. Although 7p22.1 microdeletions are rare, some reports have shown microduplications encompassing this region. In this study, we report five patients with overlapping deletions of the 7p22.1 region. The patients exhibited clinical similarities including non-specific developmental delay, short stature, microcephaly, and other distinctive features. The shortest region of overlap within the 7p22.1 region includes five genes, FBXL18, ACTB, FSCN1, RNF216, and ZNF815P. Of these genes, only ACTB is known to be associated with an autosomal dominant trait. Dominant negative mutations in ACTB are responsible for Baraitser-Winter syndrome 1. We analyzed ACTB expression in immortalized lymphocytes derived from one of the patients and found that it was reduced to approximately half that observed in controls. This indicates that ACTB expression is linearly correlated with the gene copy number. We suggest that haploinsufficiency of ACTB may be responsible for the clinical features of patients with 7p22.1 microdeletions.


Assuntos
Actinas/genética , Deficiências do Desenvolvimento/genética , Nanismo/genética , Microcefalia/genética , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/fisiopatologia , Actinas/biossíntese , Adolescente , Adulto , Criança , Pré-Escolar , Deleção Cromossômica , Cromossomos Humanos Par 7/genética , Deficiências do Desenvolvimento/fisiopatologia , Nanismo/fisiopatologia , Feminino , Expressão Gênica/genética , Haploinsuficiência/genética , Humanos , Lactente , Recém-Nascido , Linfócitos/metabolismo , Linfócitos/patologia , Masculino , Microcefalia/fisiopatologia , Fenótipo
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