High prevalence of PRPH2 in autosomal dominant retinitis pigmentosa in France and characterization of biochemical and clinical features.

International audiencePURPOSE:To assess the prevalence of PRPH2 in autosomal dominant retinitis pigmentosa (adRP), to report six novel mutations, to characterize the biochemical features of a recurrent novel mutation and to study the clinical features of adRP patients.DESIGN:Retrospective clinical and molecular genetic study.METHODS:Clinical investigations included visual field testing, fundus examination, high-resolution spectral-domain optical coherence tomography (OCT), fundus autofluorescence imaging and electroretinogram (ERG) recording. PRPH2 was screened by Sanger sequencing in a cohort of 310 French families with adRP. Peripherin-2 protein was produced in yeast and analyzed by Western blot.RESULTS:We identified 15 mutations, including 6 novel and 9 previously reported changes in 32 families, accounting for a prevalence of 10.3% in this adRP population. We showed that a new recurrent p.Leu254Gln mutation leads to protein aggregation, suggesting abnormal folding. The clinical severity of the disease in examined patients was moderate with 78% of the eyes having 1 to 0.5 of visual acuity and 52% of the eyes retaining more than 50% of the visual field. Some patients characteristically showed vitelliform deposits or macular involvement. In some families, pericentral RP or macular dystrophy were found in family members while widespread RP was present in other members of the same families.CONCLUSIONS:The mutations in PRPH2 account for 10.3% of adRP in the French population, which is higher than previously reported (0-8%) This makes PRPH2 the second most frequent adRP gene after RHO in our series. PRPH2 mutations cause highly variable phenotypes and moderate forms of adRP, including mild cases which could be underdiagnosed

Analytical methods for the evaluation of the impact of the VCO phase noise and the modulator/demodulator IQ imbalance for a QAM modulation

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Scattering of ultrasonic shock waves in suspensions of silica nanoparticles

Experiments are carried out to assess, for the first time, the validity of a generalized Burgers’ equation, introduced first by Davidson [J. Acoust. Soc. Am. 54, 1331–1342 (1973)] to compute the nonlinear propagation of finite amplitude acoustical waves in suspensions of “rigid” particles. Silica nanoparticles of two sizes (33 and 69 nm) have been synthesized in a water–ethanol mixture and precisely characterized via electron microscopy. An acoustical beam of high amplitude is generated at 1 MHz inside a water tank, leading to the formation of acoustical shock waves through nonlinear steepening. The signal is then measured after propagation in a cylinder containing either a reference solution or suspensions of nanoparticles. In this way, a “nonlinear attenuation” is obtained and compared to the numerical solution of a generalized Burgers’ equation adapted to the case of hydrosols. An excellent agreement (corresponding to an error on the particles size estimation of 3 nm) is achieved in the frequency range from 1 to 40 MHz. Both visco-inertial and thermal scattering are significant in the present case, whereas thermal effects can generally be neglected for most hydrosols. This is due to the value of the specific heat ratio of water–ethanol mixture which significantly differs from unity

Reclassification of a TMC1 synonymous substitution as a variant disrupting splicing regulatory elements associated with recessive hearing loss

International audienceAlterations of the transmembrane channel-like 1 gene (TMC1) are involved in autosomal recessive and dominant nonsyndromic hearing loss (NSHL). To date, up to 117 causal variants including substitutions, insertions and splice variants have been reported in families from different populations. In a patient suffering from severe prelingual NSHL, we identified, in the homozygous state, the previously considered likely benign synonymous c.627C>T; p.(Leu209=) substitution. We used in silico tools predicting variant-induced alterations of splicing regulatory elements (SREs) and pinpointed this transition as a candidate splice-altering variation. Functional splicing analysis, using a minigene assay, confirmed that the variant altered a critical regulatory sequence which is essential for the exon 11 inclusion in the TMC1 transcripts. This result was reinforced by the analysis of orthologous TMC1 mammalian sequences for which the deleterious effect on the mRNA processing of a native thymidine was always counteracted by the presence of a stronger donor splice site or additional enhancer motifs. This study demonstrates, for the first time, the pathogenicity of the c.627C>T alteration leading to its reclassification as a causal variant impacting SREs and highlights the major importance of exhaustive studies to accurately evaluate the pathogenicity of a variant, regardless of the variation type

Radiocommunications Numériques - Principe, Modélisation et Simulation. Tome 1

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Time Course of Inflammation and Apoptosis in a Scopolamine–Induced Dry Eye Rat Model

International audiencePurpose: : Dry eye syndrome is due to tear secretion deficiency or excessive tear evaporation leading to tear film instability. The aim of this study was to evaluate the time course of inflammation and apoptosis in a scopolamine–induced dry eye rat model. Methods: : Osmotic pumps continuously delivering scopolamine (12.5mg/d) were implanted subcutaneously in female Lewis rats for 1, 2, 3, 7, 10, 17 and 28 days. During the treatment, the corneal status was assessed by fluorescein impregnation and tears were collected for prostaglandin E2 (PGE2) immunoassay. At the end of the treatment period, the animals were sacrificed and the ocular tissues and the lacrimal glands were excised. MHCII and mucin MUC5AC were immunostained on tissue cryosections. Apoptosis was detected using the TUNEL technique and active caspase 3 immunostaining. Lipids were extracted from the lacrimal glands for fatty acid analysis. Results: : Every dry eye rat cornea exhibited keratitis after a 17–day treatment period whereas no clinical signs were observed in control animals. Apoptosis was detected mainly at the early time points (1 and 2–day treatment periods) compared to the late time points (from 10 days of treatment) but seemed to be caspase 3 independent. The number of goblet cells on the conjunctival epithelium was highly decreased after 1, 2, 10 days of treatment and more. MHCII was detected on the conjunctival epithelium and sub–epithelium of dry eye animals mainly after 7 days of treatment. Both arachidonic acid in the lacrimal glands and PGE2 in tears were increased in dry eye animals (maximum of +56% for arachidonic acid with a 10–day treatment period). Conclusions: : Altogether these results show that in this scopolamine–induced dry eye rat model, apoptosis occurs at the early time points although inflammation is detected mainly after one week of treatment

Pattern dystrophy in a female carrier of RP2 mutation

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L'Écosse des Romantiques

Actes de la journée d'étude "L'Écosse des Romantiques" du 11 janvier 2013, organisée par Georges Zaragoza et Sébastien Vacelet à l'Université de Bourgogne (Dijon). Voir URL ci-jointes :Bewitching and mysterious, exotic and picturesque, the land of Ossian and then of Walter Scott attracts the gaze and excites the curiosity of all Romantics. Scotland was invented and shaped in this 19th century, which was also the century of travel. Charles Nodier visits it, his contemporaries and his successors cherish it: from Chateaubriand to Nerval, this fascination touches well beyond two generations of poets and novelists. Simultaneously, the Caledonia of the bards like modern Scotland invite themselves on the stage of the theater, the opera, but also in the fine arts. The bookish and spectacular imagination blending here with a mythical geography, it is an open-air Scotland that is discovered step by step in the contributions of this collection where mists and vapors imprint a new way of saying and describing the colors of the time. Contributors: Fiona McIntosh-Varjabédian, Sébastien Baudoin, Francesco Schiariti, Georges Zaragoza, Samir El Maarouf, Corinne Bayle, Sandy Chotin, Benjamin Pintiaux, Sébastien Vacelet, Mélanie Guérimand, Gilles Soubigou.Envoûtante et mystérieuse, exotique et pittoresque, la terre d’Ossian puis de Walter Scott attire à elle les regards et excite la curiosité de tous les Romantiques. L’Écosse s’invente et se façonne en ce XIXe siècle qui est aussi celui du voyage. Charles Nodier la visite, ses contemporains et ses successeurs la chérissent : de Chateaubriand à Nerval, cette fascination touche bien au-delà de deux générations de poètes et de romanciers. Simultanément, la Calédonie des bardes comme l’Écosse moderne s’invitent sur la scène du théâtre, de l’opéra, mais aussi dans les beaux-arts. L’imaginaire livresque et spectaculaire se confondant ici avec une géographie mythique, c’est une Écosse à ciel ouvert qui se découvre pas à pas dans les contributions de ce recueil où brumes et vapeurs impriment une nouvelle façon de dire et de décrire les couleurs du temps.Contributeurs : Fiona McIntosh-Varjabédian, Sébastien Baudoin, Francesco Schiariti, Georges Zaragoza, Samir El Maarouf, Corinne Bayle, Sandy Chotin, Benjamin Pintiaux, Sébastien Vacelet, Mélanie Guérimand, Gilles Soubigou

Identification of the First Single GSDME Exon 8 Structural Variants Associated with Autosomal Dominant Hearing Loss

International audienceGSDME, also known as DFNA5, is a gene implicated in autosomal dominant nonsyndromic hearing loss (ADNSHL), affecting, at first, the high frequencies with a subsequent progression over all frequencies. To date, all the GSDME pathogenic variants associated with deafness lead to skipping of exon 8. In two families with apparent ADNSHL, massively parallel sequencing (MPS) integrating a coverage-based method for detection of copy number variations (CNVs) was applied, and it identified the first two causal GSDME structural variants affecting exon 8. The deleterious impact of the c.991-60_1095del variant, which includes the acceptor splice site sequence of exon 8, was confirmed by the study of the proband’s transcripts. The second mutational event is a complex rearrangement that deletes almost all of the exon 8 sequence. This study increases the mutational spectrum of the GSDME gene and highlights the crucial importance of MPS data for the detection of GSDME exon 8 deletions, even though the identification of a causal single-exon CNV by MPS analysis is still challenging

WFS1 in Optic Neuropathies: Mutation Findings in Nonsyndromic Optic Atrophy and Assessment of Clinical Severity

International audiencePURPOSE:To search for WFS1 mutations in patients with optic atrophy (OA) and assess visual impairment.DESIGN:Retrospective molecular genetic and clinical study.PARTICIPANTS:Patients with OA followed at a national referral center specialized in genetic sensory diseases.METHODS:Mutation screening in WFS1 was performed by Sanger sequencing. WFS1-positive patients were evaluated on visual acuity (VA) and retinal nerve fiber layer (RNFL) thickness using time-domain (TD) or spectral-domain (SD) optical coherence tomography (OCT). Statistical analysis was performed.MAIN OUTCOME MEASURES:Mutation identification, VA values, and RNFL thickness in sectors.RESULTS:Biallelic WFS1 mutations were found in 3 of 24 unrelated patients (15%) with autosomal recessive nonsyndromic optic atrophy (arNSOA) and in 8 patients with autosomal recessive Wolfram syndrome (arWS) associated with diabetes mellitus and OA. Heterozygous mutations were found in 4 of 20 unrelated patients (20%) with autosomal dominant OA. The 4 WFS1-mutated patients of this latter group with hearing loss were diagnosed with autosomal dominant Wolfram-like syndrome (adWLS). Most patients had VA decrease, with logarithm of the minimum angle of resolution (logMAR) values lower in arWS than in arNSOA (1.530 vs. 0.440; P = 0.026) or adWLS (0.240; P = 0.006) but not differing between arNSOA and adWLS (P = 0.879). All patients had decreased RNFL thickness that was worse in arWS than in arNSOA (SD OCT, 35.50 vs. 53.80 μm; P = 0.018) or adWLS (TD-OCT, 45.84 vs. 59.33 μm; P = 0.049). The greatest difference was found in the inferior bundle. Visual acuity was negatively correlated with RNFL thickness (r = -0.89; P = 0.003 in SD OCT and r = -0.75; P = 0.01 in TD-OCT).CONCLUSIONS:WFS1 is a gene causing arNSOA. Patients with this condition had significantly less visual impairment than those with arWS. Thus systematic screening of WFS1 must be performed in isolated, sporadic, or familial optic atrophies