52 research outputs found
Improving ROCs of Constant False Alarm Coded Anti-collision Radar in very noised cases
The use of Constant False Alarm Coded Anticollision Radar (CFACAR) is very interesting in automotive environment. Due to the orthogonality properties of used codes this system is most robust to multi-user interferences. The actual version of the receiver called in this paper Single Correlation Receiver (SCR), is not able to detect the targets in very low input Signal to Noise Ratio (SNR). To resolve this problem, we present a new receiver called Averaging Correlation Receiver (ACR), that computes the average of the M later correlations.Then, we developed the expression of detection and false alarm probabilities for the new receiver in mono and multi-user scenarios. These probabilities are used to plot the new Receiver Operating Characteristics (ROCs). They are drawn for different values of input SNR and length M of ACR. There is a suitable value of M, according to some equation, that can be taken to have a good detection (ROCs more perfect). Also, we found that for a fixed SNR, we must increase sufficiently the length M but it is possible only for low relative velocity of the target. For a velocity of 5Km=h with M = 1055, we can lessen the value of the SNR until we reach SNR = -45 dB
Identification and Characterization of Known Biallelic Mutations in the IFT27 (BBS19) Gene in a Novel Family With Bardet-Biedl Syndrome
Bardet-Biedl syndrome (BBS; MIM 209900) is a rare ciliopathy characterized by retinitis pigmentosa, postaxial polydactyly, obesity, hypogonadism, cognitive impairment and kidney dysfunction. Mutations in 22 BBS genes have been identified to cause the disease. We report a family with typical BBS features (retinitis pigmentosa, postaxial polydactyly, obesity, cognitive impairment, and atrioventricular septal defect) mutated in IFT27/BBS19. IFT27 is part of the Intraflagellar transport (IFT), a bidirectional mechanism allowing the protein motility within the cilia. Using whole exome sequencing, two compound heterozygous mutations were found in the proband (NM_006860.4:c.[104A > G];[349+1G > T], p.[Tyr35Cys];[?]) consistent with the expected autosomal recessive inheritance mode. These two mutations have already been reported but independently in other families and lacking either familial segregation or functional validation. This is the third report of IFT27 mutations in BBS patients confirming IFT27 as a BBS gene (BBS19). Mutations in IFT genes (IFT27, IFT172 and IFT74) confirm the IFT-pathway as a pathomechanism for BBS
Syndromic intellectual disabilities and ZEB2 anomalies
Les causes génétiques des syndromes avec déficiences intellectuelles sont encore peu élucidées. Les données actuelles disponibles sont très récentes et encore incomplètes. Le syndrome de Mowat-Wilson appartient à ce cadre nosologique. Il associe une déficience intellectuelle profonde et un syndrome polymalformatif comprenant une maladie de Hirschsprung, des anomalies du corps calleux, des anomalies cardiaques et urogénitales. Les causes moléculaires sont, dans la très grande majorité des cas, des mutations tronquantes de ZEB2 (ou SIP1 ou ZFHX1B). Ces anomalies surviennent de novo à l'état hétérozygote. Récemment, nous avons identifié dans notre laboratoire, trois nouvelles mutation faux-sens de ZEB2 chez trois patients ayant un phénotype modéré de la maladie. Nous montrons que ces anomalies moléculaires induisent une perte de fonction de la protéine. Les techniques de sauvetage du phénotype par injection d'ARN ZEB2 sauvage et muté montrent que, chez les embryons morphants sip1b, les protéines mutées participent partiellement au développement des dérivés neuraux et des crêtes neurales.Parallèlement à cette étude, par séquençage de l'exome, nous avons identifié chez un patient atteint de déficience intellectuelle syndromique, une mutation de CSDE1. Ce gène code une protéine à 5 domaines cold-shock, liant l'ARN et régulant la traduction dépendante de l'IRES. C'est la première fois que CSDE1 est impliqué en pathologie. Nous montrons que la mutation entraine une haploinsuffisance et dérégule la traduction de ZEB2.[Translated by Reverso web site - The genetic causes of the syndromes with intellectual deficiencies are again little clarified. The available current data are very recent and still incomplete. The syndrome of Mowat-Wilson belongs to this nosologique frame(executive). He(it) associates a deep intellectual deficiency and a polymalformatif syndrome understanding(including) a disease of Hirschsprung, anomalies of the corpus callusum, the cardiac anomalies and urogénitales. The molecular causes are, in her(it) very great majority of the cases, tronquantes transfers(transformations) of ZEB2 (or SIP1 or ZFHX1B). These anomalies arise of novo in the heterozygous state. Recently, we identified in our laboratory, three news(short stories) transfer(transformation) misinterpretation of ZEB2 at three patients having a moderate phenotype of the disease. We show that these molecular anomalies lead(infer) a loss of function(office) of the protein. The techniques of rescue of the phenotype by injection of wild and moved ARN ZEB2 show that, to morphants embryos sip1b, moved proteins participate partially in the development of by-products neuraux and neurales crests. In a parallel to(at the same time as) this study, by sequencing of the exome, we identified at a patient's reached(affected) by intellectual syndromique deficiency, a transfer(transformation) of CSDE1. This gene codes a protein in 5 domains cold-shock, linking(binding) ARN and regulating the dependent translation of IRES. It is the first time when CSDE1 is involved in pathology. We show that the transfer(transformation) entraine a haploinsuffisance and deregulate the translation of ZEB2.
Mayer-rokitansky-kunster-hauser syndrome due to 2q12. 1q14. 1 deletion: pax8 the causing gene?
International audienceMayer-Rokitansky-Küster-Hauser syndrome (MRKH) is a rare malformative disorder, characterized by congenital aplasia of the uterus and the upper two thirds of the vagina (MIM #277000). For a majority of patients, the disorder remained without identified genetic cause. However, four recurrent microdeletions, i.e. 1q21.1-16p11.2-17q12 and 22q11.21, as well as variants in genes contained in these loci, have been identified in a small number of cases. We describe an additional patient with 2q12.1q14.1 microdeletion, showing MRKH and congenital hypothyroidism due to thyroid gland hypoplasia. The patient received a dual diagnosis with microdeletion of SHOX locus in addition to the 2q12.1q14.1 microdeletion. Literature review and database analysis has enabled us to identify 5 OMIM morbid genes: CKAP2L, IL1B, IL1RN, IL36RN and PAX8. Among these, PAX8 (Paired Box Gene 8), a transcriptional factor part of the paired-box family, plays a key role in the development of the thyroid gland, kidneys and Müllerian derivatives. We discuss here the role of PAX8 and speculate on the possible involvement of PAX8 in MRKH. In this study, we report a second case of 2q12.1q14.1 microdeletion, involving PAX8 as a gene associated with Müllerian agenesis in a MRKH I and hypothyroidism. Further studies will confirm the direct participation of PAX8 in gene target sequencing in a population of MRKH with hypothyroidism
Difficulties adapting to nail-patella syndrome: a qualitative study of patients'' perspectives
International audienceNail-Patella syndrome (NPS) is a genetic disorder generating physical malformations and, in approximately one in three cases, ocular and renal damage. The present research aimed to deeply understand patients' subjective experience with NPS, particularly the aspects of the syndrome that affect patients' adaptation and to propose interventions that can improve genetic and psychological counseling and help patients cope with their condition. Semi-structured interviews of nine people diagnosed with NPS were analyzed using interpretative phenomenological analysis. Results highlighted attempts to look like a person without disabilities by hiding malformations and not telling the truth about symptoms' genetic origin because of patients' poor self-esteem, negative self-cognition, and social isolation experienced from childhood to adulthood. Difficulties of adaptation to physical limits and pain were also identified. The majority of participants who were not diagnosed at birth tended to consider physical symptoms as "birth malformations" without imagining other potential implications until receiving a diagnosis. Despite the diagnosis, the majority continued to minimize the potential complications by considering NPS as a "physical difference" and not adhering to medical surveillance
Molecular and cellular issues of kmt2a variants involved in wiedemann-steiner syndrome
International audienceVariants in KMT2A, encoding the histone methyltransferase KMT2A, are a growing cause of intellectual disability (ID). Up to now, the majority of KMT2A variants are non-sense and frameshift variants causing a typical form of Wiedemann-Steiner syndrome. We studied KMT2A gene in a cohort of 200 patients with unexplained syndromic and non-syndromic ID and identified four novel variants, one splice and three missense variants, possibly deleterious. We used primary cells from the patients and molecular approaches to determine the deleterious effects of those variants on KMT2A expression and function. For the putative splice variant c.11322-1G>A, we showed that it led to only one nucleotide deletion and loss of the C-terminal part of the protein. For two studied KMT2A missense variants, c.3460C>T (p.(Arg1154Trp)) and c.8558T>G (p.(Met2853Arg)), located at the cysteine-rich CXXC domain and the transactivation domain of the protein, respectively, we found altered KMT2A target genes expression in patient's fibroblasts compared to controls. Furthermore, we found a disturbed subcellular distribution of KMT2A for the c.3460C>T mutant. Taken together, our results demonstrated the deleterious impact of the splice variant and of the missense variants located at two different functional domains and suggested reduction of KMT2A function as the disease-causing mechanism
Le test de concordance de script à l’heure de la réforme du second cycle des études médicales en France : étude pilote en génétique médicale
Contexte : Dans les prochaines années, il est prévu d’introduire le test de concordance de script (TCS) dans le cadre des épreuves classantes nationales informatisées (ECNi). Le TCS n’a jamais été évalué pour l’enseignement de la génétique médicale du deuxième cycle. But : Élaborer un TCS pour les étudiants de deuxième cycle et évaluer ses qualités psychométriques. Déterminer les arguments docimologiques étayant la pertinence d’introduire le TCS aux ECNi. Méthode : Création d’un TCS spécifique à la discipline et administration aux étudiants de deuxième cycle et internes de génétique médicale. Administration d’une épreuve type ECNi comportant 3 dossiers progressifs (DP) et 12 questions isolées (QI) aux étudiants de deuxième cycle. Analyse du caractère discriminant du TCS par comparaison des scores obtenus par les différents groupes. Analyse de corrélation entre les scores aux TCS et DP, QI et rang de classement aux ECNi. Résultats : Les réponses de 18 experts et 129 étudiants ont été obtenues. Après optimisation, le TCS contient 15 vignettes cliniques et 34 items. Le coefficient alpha de Cronbach est de 0,67. Le test a pu discriminer le niveau des étudiants et il existe une corrélation entre les scores obtenus au TCS, aux DP, ainsi qu’avec le rang de classement aux ECNi. Conclusion : Cette étude montre la faisabilité d’un TCS standardisé pour évaluer l’enseignement de la génétique médicale, qui pourrait être aisément intégré aux ECNi. Il s’agit d’un exemple supplémentaire de la pertinence de ce type d’épreuve dans l’évaluation du raisonnement clinique des étudiants de médecine
Childhood‐onset progressive dystonia associated with pathogenic truncating variants in CHD8
International audienceOriginally described as a risk factor for autism, CHD8 loss-of-function variants have recently been associated with a wider spectrum of neurodevelopmental abnormalities. We further expand the CHD8-related phenotype with the description of two unrelated patients who presented with childhood-onset progressive dystonia. Whole-exome sequencing conducted in two independent laboratories revealed a CHD8 nonsense variant in one patient and a frameshift variant in the second. The patients had strongly overlapping phenotypes characterized by generalized dystonia with mild-to-moderate neurodevelopmental comorbidity. Deep brain stimulation led to clinical improvement in both cases. We suggest that CHD8 should be added to the growing list of neurodevelopmental disorder-associated genes whose mutations can also result in dystoniadominant phenotypes
A new lysosomal storage disorder resembling Morquio syndrome in sibs
International audienceWe report two male sibs, born from unrelated French Caribbean parents, presenting with an unclassifiable storage disorder. Pregnancy and delivery were uneventful. Stunted growth was noted during the first year of life. Both children have short stature (below - 4SD) with short trunk, barrel chest, micromelia with rhizomelic shortening, severe kyphoscoliosis, pectus carinatum, short hands and feet with metatarsus adductus, and excessive joint laxity of the small joints. Learning difficulties with borderline intelligence quotient (IQ) were noted in one of them. They had no hepatomegaly, no splenomegaly, and no dysmorphism. Skeletal X-rays survey demonstrated generalized platyspondyly with tongue-like deformity of the anterior part of the vertebral bodies, hypoplasia of the odontoid process, generalized epiphyseal dysplasia and abnormally shaped metaphyses. The acetabular roofs had a trident aspect. Ophthalmologic and cardiac examinations were normal. Spine deformity required surgical correction in one of the patient at age 4 years. Lysosomal enzymes assays including N-acetylgalactosamine-6-sulfate sulfatase and β-galactosidase were normal, excluding mucopolysaccharidoses type IV A and IV B (Morquio syndrome), respectively. Qualitative analysis found traces of dermatan and chondroitin-sulfates in urine, but quantitative glycosaminoglycan excretion fell within normal limits. They were no vacuolated lymphocytes. Abnormal coarse inclusions were present in eosinophils. Mild Alder anomaly was observed in polymorphonuclears. Granulations were discretely metachromatic with toluidine blue. Those morphological anomalies are in favor of a lysosomal storage disease. No inclusions were found in skin fibroblasts. We hypothesize that these two boys have a distinct autosomal recessive or X-linked lysosomal storage disorder of unknown origin that shares clinical and radiological features with Morquio disease
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