14 research outputs found
Fluorescent âCovalent Organic Frameworksâ for simultaneous detection and ammonia capture
National audienc
Association of covalent organic frameworks and polymers for the synthesis of raspberry particles with a radial single-crystal grain orientation.
International audienc
âCovalent Organic Frameworks-Polymersâ: from macromolecular design to nanostructured materials.
International audienc
âCovalent Organic Frameworks-Polymersâ: Landscape of particle morphologies
International audienc
Sperm meiotic segregation of a balanced interchromosomal reciprocal insertion resulting in recurrent spontaneous miscarriage
International audienc
Further refining the critical region of 10q26 microdeletion syndrome: A possible involvement of INSYN2 and NPS in the cognitive phenotype
International audienc
Feasibility of Optical Genome Mapping from Placental and Umbilical Cord Sampled after Spontaneous or Therapeutic Pregnancy Termination
Optical genome mapping (OGM) is an alternative to classical cytogenetic techniques to improve the detection rate of clinically significant genomic abnormalities. The isolation of high-molecular-weight (HMW) DNA is critical for a successful OGM analysis. HMW DNA quality depends on tissue type, sample size, and storage conditions. We assessed the feasibility of OGM analysis of DNA from nine umbilical cord (UC) and six chorionic villus (CV) samples collected after the spontaneous or therapeutic termination of pregnancy. We analyzed quality control metrics provided by the Saphyr system (Bionano Genomics) and assessed the length of extracted DNA molecules using pulsed-field capillary electrophoresis. OMG data were successfully analyzed for all six CV samples. Five of the UC samples did not meet the Saphyr quality criteria, mainly due to poor DNA quality. In this regard, we found that DNA quality assessment with pulsed-field capillary electrophoresis can predict a successful OGM analysis. OGM data were fully concordant with the results of standard cytogenetic methods. Moreover, OGM detected an average of 14 additional structural variants involving OMIM genes per sample. On the basis of our results, we established the optimal conditions for sample storage and preparation required for a successful OGM analysis. We recommend checking DNA quality before analysis with pulsed-field capillary electrophoresis if the storage conditions were not ideal or if the quality of the sample is poor. OGM can therefore be performed on fetal tissue harvested after the termination of pregnancy, which opens up the perspective for improved diagnostic yield
Evidence for high breakpoint variability in 46, XX, SRYâpositive testicular disorder and frequent ARSE deletion that may be associated with short stature
International audienceBackground: The translocation of SRY onto one of the two X chromosomes results in a 46,XX testicular disorder of sex development; this is supposedly due to non-allelic homologous recombination between the protein kinase X gene (PRKX) and the inverted protein kinase Y pseudogene (PRKY). Although 46,XX SRY-positive men are infertile, the literature data indicate that some of these individuals are of short stature (relative to the general population). We sought to determine whether short stature was linked to additional, more complex chromosomal rearrangements.Methods: Twelve laboratories gathered detailed clinical, anthropomorphic, cytogenetic and genetic data (including chromosome microarray (CMA) data) on patients with 46,XX SRY-positive male syndrome.Results: SRY was present (suggesting a der(X)t(X;Y)) in 34 of the 38 cases (89.5%). When considering only the 20 patients with CMA data, we identified several chromosomal rearrangements and breakpoints - especially on the X chromosome. In the five cases for whom the X chromosome breakpoint was located in the pseudoautosomal (PAR) region, there was partial duplication of the derivate X chromosome. In contrast, in the 15 cases for whom the breakpoint was located downstream of the pseudoautosomal region, part of the derivate X chromosome had been deleted (included the arylsulfatase E (ARSE) gene in 11 patients). For patients with vs. without ARSE deletion, the mean height was respectively 167.7 ± 4.5 and 173.1 ± 4.0 cm; this difference was not statistically significant (p = 0.1005).Conclusion: Although 46,XX SRY-positive male syndromes were mainly due to imbalanced crossover between the X and Y chromosome during meiosis, the breakpoints differed markedly from one patient to another (especially on the X chromosome); this suggests the presence of a replication-based mechanism for recombination between non-homologous sequences. In some patients, the translocation of SRY to the X chromosome was associated with ARSE gene deletion, which might have led to short stature. With a view to explaining this disorder of sex development, whole exome sequencing could be suggested for SRY-negative patients. This article is protected by copyright. All rights reserved