Showing papers by "Paul Coucke published in 2010"
TL;DR: It is reported that stiff skin syndrome (SSS), an autosomal dominant congenital form of scleroderma, is caused by mutations in the sole Arg-Gly-Asp sequence–encoding domain of fibrillin-1 that mediates integrin binding, which is consistent with a model in which integrins provide a means for cells to sample the matrix and to adjust their synthetic repertoire accordingly.
Abstract: The predisposition for scleroderma, defined as fibrosis and hardening of the skin, is poorly understood. We report that stiff skin syndrome (SSS), an autosomal dominant congenital form of scleroderma, is caused by mutations in the sole Arg-Gly-Asp sequence-encoding domain of fibrillin-1 that mediates integrin binding. Ordered polymers of fibrillin-1 (termed microfibrils) initiate elastic fiber assembly and bind to and regulate the activation of the profibrotic cytokine transforming growth factor-beta (TGFbeta). Altered cell-matrix interactions in SSS accompany excessive microfibrillar deposition, impaired elastogenesis, and increased TGFbeta concentration and signaling in the dermis. The observation of similar findings in systemic sclerosis, a more common acquired form of scleroderma, suggests broad pathogenic relevance.
200 citations
TL;DR: Exhaustive re‐inspection of the overall phenotypes in the LCA cohort revealed novel insights mainly regarding the CEP290‐related phenotype, and a heterozygous novel AHI1 mutation, p.Asn811Lys, was found in the most severely affected patient.
Abstract: Leber Congenital Amaurosis (LCA), the most severe inherited retinal dystrophy, is genetically heterogeneous, with 14 genes accounting for 70% of patients. Here, 91 LCA probands underwent LCA chip analysis and subsequent sequencing of 6 genes (CEP290, CRB1, RPE65, GUCY2D, AIPL1and CRX), revealing mutations in 69% of the cohort, with major involvement of CEP290 (30%). In addition, 11 patients with early-onset retinal dystrophy (EORD) and 13 patients with Senior-Loken syndrome (SLS), LCA-Joubert syndrome (LCA-JS) or cerebello-oculo-renal syndrome (CORS) were included. Exhaustive re-inspection of the overall phenotypes in our LCA cohort revealed novel insights mainly regarding the CEP290-related phenotype. The AHI1 gene was screened as a candidate modifier gene in three patients with the same CEP290 genotype but different neurological involvement. Interestingly, a heterozygous novel AHI1 mutation, p.Asn811Lys, was found in the most severely affected patient. Moreover, AHI1 screening in five other patients with CEP290-related disease and neurological involvement revealed a second novel missense variant, p.His758Pro, in one LCA patient with mild mental retardation and autism. These two AHI1 mutations might thus represent neurological modifiers of CEP290-related disease. © 2010 Wiley-Liss, Inc.
139 citations
Ghent University1, Johns Hopkins University2, Children's Hospital of Wisconsin3, University of Sydney4, University of Gaziantep5, University of Kansas6, University of Erlangen-Nuremberg7, University of Zurich8, Medical College of Wisconsin9, Oregon Health & Science University10, Johns Hopkins University School of Medicine11
TL;DR: Patients with recessive FBLN4 mutations are predominantly characterized by aortic aneurysms, arterial tortuosity and stenosis, which confirms the important role of fibulin-4 in vascular elastic fiber assembly and provides the first evidence for the involvement of altered TGFβ signaling in the pathogenesis of FBLn4 mutations in humans.
Abstract: Fibulin-4 is a member of the fibulin family, a group of extracellular matrix proteins prominently expressed in medial layers of large veins and arteries. Involvement of the FBLN4 gene in cardiovascular pathology was shown in a murine model and in three patients affected with cutis laxa in association with systemic involvement. To elucidate the contribution of FBLN4 in human disease, we investigated two cohorts of patients. Direct sequencing of 17 patients with cutis laxa revealed no FBLN4 mutations. In a second group of 22 patients presenting with arterial tortuosity, stenosis and aneurysms, FBLN4 mutations were identified in three patients, two homozygous missense mutations (p.Glu126Lys and p.Ala397Thr) and compound heterozygosity for missense mutation p.Glu126Val and frameshift mutation c.577delC. Immunoblotting analysis showed a decreased amount of fibulin-4 protein in the fibroblast culture media of two patients, a finding sustained by diminished fibulin-4 in the extracellular matrix of the aortic wall on immunohistochemistry. pSmad2 and CTGF immunostaining of aortic and lung tissue revealed an increase in transforming growth factor (TGF)β signaling. This was confirmed by pSmad2 immunoblotting of fibroblast cultures. In conclusion, patients with recessive FBLN4 mutations are predominantly characterized by aortic aneurysms, arterial tortuosity and stenosis. This confirms the important role of fibulin-4 in vascular elastic fiber assembly. Furthermore, we provide the first evidence for the involvement of altered TGFβ signaling in the pathogenesis of FBLN4 mutations in humans.
139 citations
Ghent University Hospital1, University of Southern Denmark2, Karolinska University Hospital3, Necker-Enfants Malades Hospital4, VU University Medical Center5, University College Dublin6, University College London7, University of Amsterdam8, Leiden University Medical Center9, Radboud University Nijmegen Medical Centre10, University of Sydney11, Children's Hospital at Westmead12, Guy's Hospital13, Helsinki University Central Hospital14, Radboud University Nijmegen15, Hospital Sant Joan de Déu Barcelona16, St George's, University of London17, St. Michael's GAA, Sligo18, University of Southampton19, Erasmus University Rotterdam20, Casa Sollievo della Sofferenza21, Boston Children's Hospital22
TL;DR: It is confirmed that Stickler syndrome type 1 is predominantly caused by loss-of-function mutations in the COL2A1 gene as >90% of the mutations were predicted to result in nonsense-mediated decay.
Abstract: Stickler syndrome is an autosomal dominant connective tissue disorder caused by mutations in different collagen genes. The aim of our study was to define more precisely the phenotype and genotype of Stickler syndrome type 1 by investigating a large series of patients with a heterozygous mutation in COL2A1. In 188 probands with the clinical diagnosis of Stickler syndrome, the COL2A1 gene was analyzed by either a mutation scanning technique or bidirectional fluorescent DNA sequencing. The effect of splice site alterations was investigated by analyzing mRNA. Multiplex ligation-dependent amplification analysis was used for the detection of intragenic deletions. We identified 77 different COL2A1 mutations in 100 affected individuals. Analysis of the splice site mutations showed unusual RNA isoforms, most of which contained a premature stop codon. Vitreous anomalies and retinal detachments were found more frequently in patients with a COL2A1 mutation compared with the mutation-negative group (P 90% of the mutations were predicted to result in nonsense-mediated decay. On the basis of binary regression analysis, we developed a scoring system that may be useful when evaluating patients with Stickler syndrome.
112 citations
TL;DR: Although in PXE-like patients this is due to mutations in the GGCX gene, a deficiency of the carboxylation co-factor VK is at the basis of the decreased activity of calcification inhibitors in PxE.
69 citations
TL;DR: The results further illustrate the instability of the ABCC6 genomic region and stress the importance of screening for deletions in the molecular diagnosis of PXE.
Abstract: Mutations in ABCC6 cause pseudoxanthoma elasticum (PXE), a heritable disease that affects elastic fibers. Thus far, >200 mutations have been characterized by various PCR-based techniques (primarily direct sequencing), identifying up to 90% of PXE-causing alleles. This study wanted to assess the importance of deletions and insertions in the ABCC6 genomic region, which is known to have a high recombinational potential. To detect ABCC6 deletions/insertions, which can be missed by direct sequencing, multiplex ligation-dependent probe amplification (MLPA) was applied in PXE patients with an incomplete genotype. MLPA was performed in 35 PXE patients with at least one unidentified mutant allele after exonic sequencing and exclusion of the recurrent exon 23-29 deletion. Six multi-exon deletions and four single-exon deletions were detected. Using MLPA in addition to sequencing, we expanded the ABCC6 mutation spectrum with 9 novel deletions and characterized 25% of unidentified disease alleles. Our results further illustrate the instability of the ABCC6 genomic region and stress the importance of screening for deletions in the molecular diagnosis of PXE.
30 citations
TL;DR: Infrared, red-free and autofluorescence imaging are more sensitive than white light funduscopy and imaging in visualising early retinal signs of PXE, and increases the chances of making a correct diagnosis early, and aids in the accurate evaluation of evolution of disease in the ophthalmic follow-up of PxE patients.
Abstract: Purpose: Pseudoxanthoma Elasticum (PXE) is an autosomal recessive disorder caused by mutations in the ABCC6 gene, and primarily affects the oculocutaneous and cardiovascular systems. However, the phenotype, including the ophthalmological manifestations, varies in severity. The present study aims to evaluate the added value of novel fundoscopic imaging techniques, such as infrared, red-free and autofluorescence imaging in PXE. Methods: In 22 molecularly proven PXE patients and 25 obligate carriers, PXE retinopathy was evaluated using funduscopy, white light, red-free, infrared and autofluorescence imaging. Results: At least one characteristic of PXE retinopathy was evident on fundoscopy of all eyes. Angioid streaks could be subdivided in those with (brick red) or without (feathered) adjacent RPE alterations. Infrared imaging showed the brick red coloured streaks as well-demarcated dark fissures, even when these passed unnoticed on funduscopy. Feathered types were detected as triangular areas of hypo-autofluorescence. The peau d’orange was much better visible and much more widespread on infrared imaging, with extension from the posterior pole towards the whole midperiphery. Comets and comet tails were best seen with red-free imaging. Conclusions: Infrared, red-free and autofluorescence imaging are more sensitive than white light funduscopy and imaging in visualizing early retinal signs of PXE. In addition, this specialised imaging allows better appreciation of the extent of lesions. Hence, such imaging increases the chances of making a correct diagnosis early, and aids in the accurate evaluation of evolution of disease in the ophthalmic follow-up of PXE patients.
27 citations
TL;DR: An open-source database oriented pipeline that enables advanced analysis of 454/Roche GS-FLX amplicon resequencing experiments using SQL-statements and a modular database approach allows easy coupling with other pipeline modules such as variant interpretation or a LIMS system.
Abstract: Next-generation amplicon sequencing enables high-throughput genetic diagnostics, sequencing multiple genes in several patients together in one sequencing run. Currently, no open-source out-of-the-box software solution exists that reliably reports detected genetic variations and that can be used to improve future sequencing effectiveness by analyzing the PCR reactions. We developed an integrated database oriented software pipeline for analysis of 454/Roche GS-FLX amplicon resequencing experiments using Perl and a relational database. The pipeline enables variation detection, variation detection validation, and advanced data analysis, which provides information that can be used to optimize PCR efficiency using traditional means. The modular approach enables customization of the pipeline where needed and allows researchers to adopt their analysis pipeline to their experiments. Clear documentation and training data is available to test and validate the pipeline prior to using it on real sequencing data. We designed an open-source database oriented pipeline that enables advanced analysis of 454/Roche GS-FLX amplicon resequencing experiments using SQL-statements. This modular database approach allows easy coupling with other pipeline modules such as variant interpretation or a LIMS system. There is also a set of standard reporting scripts available.
19 citations
TL;DR: Cytogenetic and Array-CGH Characterization of a 6q27 Deletion in a Patient With Developmental Delay and Features of Ehlers–Danlos Syndrome and its implications are described.
Abstract: Cytogenetic and Array-CGH Characterization of a 6q27 Deletion in a Patient With Developmental Delay and Features of Ehlers–Danlos Syndrome A.L. Mosca,* P. Callier, A. Masurel-Paulet, C. Thauvin-Robinet, N. Marle, M. Nouchy, F. Huet, D. Dipanda, A. De Paepe, P. Coucke, F. Mugneret, and L. Faivre D epartement de G en etique, CHU le Bocage, Dijon, France Laboratoire Pasteur Cerba, Val-d’Oise, France Service de R e education et de R eadaptation, CHU le Bocage, Dijon, France Center for Medical Genetics, Medical Research Building, Ghent, Belgium
8 citations
TL;DR: This book is dedicated to the memory of those who died in the line of duty during the conflicts of World War One and World War Two.
Abstract: Kristien P Hoornaert, Inge Vereecke, Chantal Dewinter, Thomas Rosenberg, Frits A Beemer, Jules G Leroy, Laila Bendix, Erik Björck, Maryse Bonduelle, Odile Boute, Valerie Cormier-Daire, Christine De Die-Smulders, Anne Dieux-Coeslier, Hélène Dollfus, Mariet Elting, Andrew Green, Veronica I Guerci, Raoul CM Hennekam, Yvonne Hilhorts-Hofstee, Muriel Holder, Carel Hoyng, Kristi J Jones, Dragana Josifova, Ilkka Kaitila, Suzanne Kjaergaard, Yolande H Kroes, Kristina Lagerstedt, Melissa Lees, Martine LeMerrer, Cinzia Magnani, Carlo Marcelis, Loreto Martorell, Michèle Mathieu, Meriel McEntagart, Angela Mendicino, Jenny Morton, Gabrielli Orazio, Véronique Paquis, Orit Reish, Kalle OJ Simola, Sarah F Smithson, Karen I Temple, Elisabeth Van Aken, Yolande Van Bever, Jenneke van den Ende, Johanna M Van Hagen, Leopoldo Zelante, Riina Zordania, Anne De Paepe, Bart P Leroy, Marc De Buyzere, Paul J Coucke and Geert R Mortier
4 citations
TL;DR: A 10-year-old male proband, born from consanguineous marriage, presenting with short stature, severe aortic root dilation, skin hyperextensibility, extreme joint laxity and craniofacial dysmorphism is reported.
Abstract: We report a 10-year-old male proband, born from consanguineous marriage, presenting with short stature, severe aortic root dilation, skin hyperextensibility, extreme joint laxity and craniofacial dysmorphism. Clinical, biochemical and molecular findings did not match any of the well-described connective tissue syndromes in the differential diagnosis for this specific combination of features. We presume that the phenotype presented in this patient may constitute a newly recognized syndrome of likely autosomal recessive inheritance.