Prenatal BoBsTM in the cytogenetic analysis of products of spontaneous miscarriage

Background. Fifty percent of spontaneous miscarriages (SMs) are attributed to chromosomal abnormalities. Cytogenetic analysis is an important tool for patient counselling and assessment of the risk of recurrence in future pregnancies. Conventional karyotyping has been the gold standard for chromosomal investigation of products of conception (POC), but it has limitations due to sample maceration, culture failure and maternal cell contamination. Molecular cytogenetic approaches have therefore been developed and found valuable in the cytogenetic investigation of these samples. The Prenatal BoBsTM and KaryoLite BoBsTM, based on the newly developed BACs-on-BeadsTM technology, have been described as reliable tests for rapid detection of aneuploidies in prenatal and POC samples, respectively.Objective. To describe our clinical experience of routine screening of POC samples with Prenatal BoBsTM, the test used by our laboratory in France.Methods. Seventeen samples collected at the University Hospital of Sidi Bel Abbès (Western Algeria) and a further 60 from the University Hospital of Clermont-Ferrand (France) were analysed (19 chorionic villi from products of curettage, 12 placentas, 9 amniotic cells and 37 biopsy specimens). All were screened for the frequent aneuploidies (chromosomes 13, 18, 21, X and Y) in addition to nine microdeletion/microduplication syndrome regions by Prenatal BoBsTM. Standard karyotyping was performed on 51 samples, but failed in 38 cases.Results. Prenatal BoBsTM identified one trisomy 21 and one deletion of 17p13.3. Furthermore, it provided a conclusive result in cases of culture failure (n=38) and in samples with macerated tissue (n=19). The overall failure rate was 11.4%.Conclusions. Prenatal BoBsTM is a promising technology that represents a fast, sensitive and robust alternative to routine screening for chromosomal abnormality in products of SM. Furthermore, it overcomes the limitations of conventional karyotyping and current molecular cytogenetic techniques

SCN5A mutations and the role of genetic background in the pathophysiology of Brugada syndrome.

International audienceBACKGROUND: Mutations in SCN5A are identified in approximately 20% to 30% of probands affected by Brugada syndrome (BrS). However, in familial studies, the relationship between SCN5A mutations and BrS remains poorly understood. The aim of this study was to investigate the association of SCN5A mutations and BrS in a group of large genotyped families. METHODS AND RESULTS: Families were included if at least 5 family members were carriers of the SCN5A mutation, which was identified in the proband. Thirteen large families composed of 115 mutation carriers were studied. The signature type I ECG was present in 54 mutation carriers (BrS-ECG+; 47%). In 5 families, we found 8 individuals affected by BrS but with a negative genotype (mutation-negative BrS-ECG+). Among these 8 mutation-negative BrS-ECG+ individuals, 3, belonging to 3 different families, had a spontaneous type I ECG, whereas 5 had a type I ECG only after the administration of sodium channel blockers. One of these 8 individuals had also experienced syncope. Mutation carriers had, on average, longer PR and QRS intervals than noncarriers, demonstrating that these mutations exerted functional effects. CONCLUSIONS: Our results suggest that SCN5A mutations are not directly causal to the occurrence of a BrS-ECG+ and that genetic background may play a powerful role in the pathophysiology of BrS. These findings add further complexity to concepts regarding the causes of BrS, and are consistent with the emerging notion that the pathophysiology of BrS includes various elements beyond mutant sodium channels

Aspects génétique du risque arythmogène (Polymorphysmes des canaux ioniques cardiaques et identification d' un nouveau locus responsable du syndrome de Brugada)

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Retinoid Pathway and Congenital Diaphragmatic Hernia: Hypothesis from the Analysis of Chromosomal Abnormalities

International audienceAlthough there is strong evidence implicating genetic factors in congenital diaphragmatic hernia (CDH) pathogenesis, few causal genes have been identified. Many studies suggest that early disruption of the retinoid signaling pathway during gestation may contribute to CDH etiology. Chromosome abnormalities are detected in 10-20% of CDH cases. Chromosomal regions that are involved in balanced translocations or are recurrently deleted or duplicated in patients with CDH are of particular interest to researchers because they are more likely to harbor genes that cause or predispose one to the development of CDH. The aim of this review was to select chromosome loci which have been shown to be associated with CDH and to investigate if these loci contain candidate genes involved in the retinoic signaling pathway

Fetal skin fibroblasts: A cell model for studying the retinoid pathway in congenital diaphragmatic hernia

International audienceAlthough there is strong evidence that genetic factors play a pathogenic role in congenital diaphragmatic hernia (CDH), few causal genes have been identified in humans. A number of studies, essentially in animal models, have suggested that disruption of the retinoid signaling pathway plays a major role in the pathogenesis of CDH. Our hypothesis is that human fetal skin fibroblasts express some metabolic and molecular actors of the retinoid pathway and that they offer convenient cellular material for investigating the molecular retinoid pathway defects associated with CDH

Evaluation des stratégies de diagnostic des anomalies chromosomiques en cas d’anomalie fœtale identifiée par échographie prénatale: Analyse économique

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Spatial organization of chromosome territories in the interphase nucleus of trisomy 21 cells

International audienceIn the interphase cell nucleus, chromosomes adopt a conserved and non-random arrangement in subnuclear domains called chromosome territories (CTs). Whereas chromosome translocation can affect CT organization in tumor cell nuclei, little is known about how aneuploidies can impact CT organization. Here, we performed 3D-FISH on control and trisomic 21 nuclei to track the patterning of chromosome territories, focusing on the radial distribution of trisomic HSA21 as well as 11 disomic chromosomes. We have established an experimental design based on cultured chorionic villus cells which keep their original mesenchymal features including a characteristic ellipsoid nuclear morphology and a radial CT distribution that correlates with chromosome size. Our study suggests that in trisomy 21 nuclei, the extra HSA21 induces a shift of HSA1 and HSA3 CTs out toward a more peripheral position in nuclear space and a higher compaction of HSA1 and HSA17 CTs. We posit that the presence of a supernumerary chromosome 21 alters chromosome compaction and results in displacement of other chromosome territories from their usual nuclear position

Développement d’un modèle de culture cellulaire 3D d’une lignée d’adénocarcinome mammaire triple-négatif impliquant une matrice extra-cellulaire de type trisomie 21

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Further refining the critical region of 10q26 microdeletion syndrome: A possible involvement of INSYN2 and NPS in the cognitive phenotype

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