108 research outputs found
Alternative Splicing of In-Frame Exon Associated with Premature Termination Codons: Implications for Readthrough Therapies
No full textThe correction of premature termination codons (PTCs) by agents that promote readthrough represents a promising emerging tool for the treatment of many genetic diseases. The efficiency of the treatment, however, varies depending on the stop codon itself and the amount of correctible transcripts related to the efficiency of nonsense-mediated decay. In the current study, a screen by in vitro minigene assay of all six PTCs described in exon 15 of the CFTR gene demonstrated alternative splicing to differing degrees for five of them. Of the five, PTC mutations c.2537G>A (p.Trp846*(UAG) ) and c.2551C>T (p.Arg851*) cause the greatest proportion of transcripts lacking exon 15; both mutations altering exonic splicing regulatory elements. In order to increase the amount of full-length transcripts, different pharmacological treatments were performed showing both negative and positive effects on exon inclusion for the same mutation. Therefore, the total amount of transcripts together with the splicing profile should be assessed to anticipate and improve efficacy of readthrough therapy
XRCC4-related microcephalic primordial dwarfism: description of a clinical series of 7 cases, phenotype expansion and new diagnostic approaches
No full textAbstract The non-homologous end joining (NHEJ) pathway is essential to repair DNA double-strand breaks. XRCC4 acts as a stabilizer of the DNA ligase LIG4 in the NHEJ process. In humans, XRCC4 pathogenic variants are responsible for a microcephalic primordial dwarfism syndrome (MPD). Currently, 17 patients have been reported with XRCC4 -related MPD and we report 7 new patients from 6 different families, including one fetus. The patients present with short stature, severe microcephaly, neurodevelopmental disorder and additional features, such as transient increase in nuchal translucency, congenital glaucoma, thumb anomalies, hepatic steatosis, seizures, essential tremor and oligodontia which have not been previously described. Hyper- and hypopigmented skin macules, dermatofibrosarcoma, mandibular osteoid osteoma and pancytopenia are also new features, reminiscent of cancer susceptibility syndromes. Functional studies were performed on two patients carrying the known pathogenic p.(Trp43Arg) variant in homozygous state, using a fast, cost-effective and non-invasive approach on PBMCs: (1) Survival analyses after ionizing radiation confirm important radiosensitivity. (2) Flow cytometry showed the lack of TCR-Va7+ T-lymphocytes, suggesting recombination defect of V(D)J coding segments. (3) This was confirmed by multiplexed RT-PCR (PROMIDISα biomarker), analyzing the diversity of V(D)J coding segments in a subset of the TCRα repertoire. We therefore extend the phenotype of XRCC4 -related MPD and suggest a combination of three functional assays, based on radiosensitivity and V(D)J recombination defect, to improve the interpretation of XRCC4 variants in fast, cost-effective and non-invasive manner. These findings will improve the diagnosis, genetic counselling, follow-up and management of these patients.Hospices Civils de Lyon 501100006451Neurological Foundation of New Zealand 50110000154
14q12 and severe Rett-like phenotypes: new clinical insights and physical mapping of FOXG1-regulatory elements
No full textAdvance online publication 27 June 2012The Forkhead box G1 (FOXG1) gene has been implicated in severe Rett-like phenotypes. It encodes the Forkhead box protein G1, a winged-helix transcriptional repressor critical for forebrain development. Recently, the core FOXG1 syndrome was defined as postnatal microcephaly, severe mental retardation, absent language, dyskinesia, and dysgenesis of the corpus callosum. We present seven additional patients with a severe Rett-like neurodevelopment disorder associated with de novo FOXG1 point mutations (two cases) or 14q12 deletions (five cases). We expand the mutational spectrum in patients with FOXG1-related encephalopathies and precise the core FOXG1 syndrome phenotype. Dysgenesis of the corpus callosum and dyskinesia are not always present in FOXG1-mutated patients. We believe that the FOXG1 gene should be considered in severely mentally retarded patients (no speech-language) with severe acquired microcephaly (−4 to−6 SD) and few clinical features suggestive of Rett syndrome. Interestingly enough, three 14q12 deletions that do not include the FOXG1 gene are associated with phenotypes very reminiscent to that of FOXG1-mutation-positive patients. We physically mapped a putative long-range FOXG1-regulatory element in a 0.43 Mb DNA segment encompassing the PRKD1 locus. In fibroblast cells, a cis-acting regulatory sequence located more than 0.6 Mb away from FOXG1 acts as a silencer at the transcriptional level. These data are important for clinicians and for molecular biologists involved in the management of patients with severe encephalopathies compatible with a FOXG1-related phenotype.Lila Allou, Laetitia Lambert, Daniel Amsallem, Eric Bieth, Patrick Edery, Anne Destrée, François Rivier, David Amor, Elizabeth Thompson, Julian Nicholl, Michael Harbord, Christophe Nemos, Aline Saunier, Aissa Moustaïne, Adeline Vigouroux, Philippe Jonveaux and Christophe Philipp
Profilométrie par courants de Foucault de la zone de dudgeonnage des tubes de générateurs de vapeur
No full textA study of the dimer formation of Rous sarcoma virus RNA and of its effect on viral protein synthesisin vitro
No full textNovel IL1RAPL1 mutations associated with intellectual disability impair synaptogenesis
No full textMutations in interleukin-1 receptor accessory protein like 1 (IL1RAPL1) gene have been associated with non-syndromic intellectual disability and autism spectrum disorder. This protein interacts with synaptic partners like PSD-95 and PTPδ, regulating the formation and function of excitatory synapses. The aim of this work is to characterize the synaptic consequences of three IL1RAPL1 mutations, two novel causing the deletion of exon 6 (Δex6) and one point mutation (C31R), identified in patients with intellectual disability. Using immunofluorescence and electrophysiological recordings we examined the effects of IL1RAPL1 mutants over-expression on synapse formation and function in cultured rodent hippocampal neurons. Δex6 but not C31R mutation leads to IL1RAPL1 protein instability and mislocalization within dendrites. Analysis of different markers of excitatory synapses and sEPSC recording revealed that both mutants fail to induce pre- and post-synaptic differentiation, contrary to WT IL1RAPL1 protein. Cell aggregation and immunoprecipitation assays in HEK293 cells showed a reduction of the interaction between IL1RAPL1 mutants and PTPδ that could explain the observed synaptogenic defect in neurons. However, these mutants do not affect all cellular signaling since their over-expression still activates JNK pathway. We conclude that both mutations described in this study lead to a partial loss of function of the IL1RAPL1 protein through different mechanisms. Our work highlights the important function of the trans-synaptic PTPδ/ IL1RAPL1 interaction in synaptogenesis and as such, in intellectual disability in the patients.Mariana Ramos-Brossier, Caterina Montani, Nicolas Lebrun, Laura Gritti, Christelle Martin, Christine Seminatore-Nole, Aurelie Toussaint, Sarah Moreno, Karine Poirier, Olivier Dorseuil, Jamel Chelly, Anna Hackett, Jozef Gecz, Eric Bieth, Anne Faudet, Delphine Heron, R. Frank Kooy, Bart Loeys, Yann Humeau, Carlo Sala and Pierre Billuar
Fibroblast Growth Factor Receptor 3 Epidermal Naevus Syndrome with Urothelial Mosaicism for the Activating p.Ser249Cys FGFR3 Mutation
No full textInternational audienceFibroblast growth factor receptor 3 epidermal naevus syndrome (FGFR3-ENS), also known as Garcia-HafnerHapple syndrome, is a rare and distinctive epidermal naevus (EN) syndrome, clinically characterized by a systematized keratinocytic EN of soft and velvety type, with inconstant cerebral and skeletal involvement (1). We report here a new case of FGFR3-ENS with the postzygotic FGFR3 p.Ser249Cys mutation detected in both affected skin and urothelial cell
Maître des origines, figure du progrès : l'archéologue au miroir des images
No full textMaster of the origins, actor of progress : a multi-faceted view of the archeologist.
The figure of the archeologist as a key person of modem societies takes shape around a double définition : master of the origins and actor of progress. Since the 18th century down to our time, it has fallen to him to handle the official speech about the origins of man thus replacing the mythical or religious view by a rational line organized around the idea of progress.
From this image-making we can single out three main stages. At the turn of the 19th century, we notice the birth of a new figure which substitutes for the amateur or the antique dealer. Subsequendy, that personality gains consistency ail along the 19th century, outlining three shapes in turn or at the same time : the scholar, the adventurer and the mediator of the past. Ail three sides still are part of the present day archeologist. But a new dimension has emerged recendy, that of a «return to eath » in some sort, earth as the primai womb giving bieth to a new mythology.
The author bases his historic construction on iconic representations, ranging from the oldest engravings to the most recent photographs.</jats:p
Infrastructure métropolitaine de continuité socio-écologique. Vers des milieux ouverts structurants: services écosystémiques et transition socio-écologique
No full textLAB-USteering Committee: Emmanuel Ansaldi (OCAN), Frédéric Bachmann (OCEau / DT), Laurent Badoux (OU / DT), Valentina Hemmeler Maïga (OCAN / DT), Mathieu Iglesias (DPA / DT), Charlotte Le Gouic (Pôle métropolitain du Genevois français), Thierry Maeder (Région de Nyon), Güner Sengul Juranville (DPA / DT), Eric Zellweger (OU / DT
Gingival Biopsy to Detect Mosaicism in Overgrowth Syndromes: Report of Two Cases of Megalencephaly-Capillary Malformation Syndrome with Periodontal Anomalies
No full textBackground. Megalencephaly-capillary malformation (MCAP) is a rare overgrowth syndrome caused by postzygotic activating mutations in the PIK3CA gene. Aim. To illustrate the benefits of gingival biopsy in the genetic diagnosis of overgrowth syndromes. Design. Gingival biopsy was performed on a 13-year-old patient and a 16-year-old patient with MCAP and who suffered from periodontal disease. PIK3CA sequencing was performed on DNA extracted from gingival biopsies, blood, and saliva. Results. Pathogenic p.Glu365Lys and p.Glu545Asp PIK3CA mutations were found in the gingival biopsies with an allelic frequency of 22% and 35%, respectively, while they were undetectable in blood or saliva. The genetic diagnosis of MCAP through detection of PIK3CA somatic mosaicism in a periodontal biopsy is unprecedented. Conclusions. Considering the tissue distribution and level of somatic mosaicism for PIK3CA mutation, the composite embryologic origin of periodontium and its high fibroblast cell content make it an ideal target for molecular analysis in overgrowth syndromes, and multidisciplinary approach including paediatric dentists should be encouraged. In addition, our clinical findings suggest that periodontal disease is part of the MCAP phenotypic spectrum and should be systematically investigated
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