Search

Une des clés d’un dépistage réussi résidant dans la bonne information des patientes, les prescripteurs doivent être eux-mêmes formés aux enjeux du test. L’article pointe le rôle du cytogénéticien à cet égard. Il doit présenter les performances du test sous la forme de valeurs prédictives (probabilité que le résultat du test soit juste en ce qui concerne la patiente) ; rappeler que le droit de savoir a comme corollaire celui de ne pas savoir ; soutenir que sauf contre-indications médicales, l’accès au dépistage doit être possible même en dehors des indications de prise en charge par la sécurité sociale (c’est-à-dire à ce jour la trisomie 21), si les autres anomalies decelables sont de mauvais pronostic et que leur dépistage ne génère pas trop de prélèvements invasifs ; en collaboration avec le prescripteur, lorsque le DPNI est positif pour une anomalie rare, prodiguer un conseil génétique. One of the keys to successful NIPT is a good patient and prescribers information. The article highlights the role of the cytogeneticist in this regard. He or she should present the performance of the test in the form of predictive values (the probability that the test result is correct for the patient); recall that the right to know has as its corollary the right not to know; he or she should maintain that, except for medical contraindications, access to screening should be possible even outside the indications covered by the French health insurance (to date, trisomy 21) if the other detectable anomalies are of bad prognosis and if their detection does not generate too many invasive samples; in collaboration with the prescriber, when the NIPT is positive for a rare anomaly, it is the cytogeneticist’s responsibility to provide genetic counseling.

A supernumerary marker chromosome (SMC) is a structurally abnormal chromosome that cannot be characterized by conventional banding cytogenetics. Marker chromosomes are present in 0.075% of prenatal cases. They are associated with variable phenotypes, ranging from normal to severely abnormal, and the prognosis is largely dependent on the results of further cytogenomic analysis. Here, we report the identification and characterization of a marker chromosome following prenatal screening in a 39-year-old pregnant patient. The patient had a normal first trimester ultrasound but was high-risk for fetal chromosome anomalies based on the results of maternal serum parameters. Chorionic villus sampling was performed, and analysis of chorionic villi revealed the presence of two identical marker chromosomes. In the interest of a rapid identification of the markers, we performed noninvasive prenatal testing (NIPT) together with chorionic villus sampling. A pericentromeric 29 Mb duplication of chromosome 20: dup (20) (p13q11.21) was identified and thereafter confirmed by targeted metaphasic FISH. Whole-genome sequencing-based NIPT was instrumental in rapid characterization of the SMCs and allowed us to obviate the need for multiple expensive and time-consuming FISH analyses.

CIANB:Com foco na importância da Logística e na qualidade da aplicação dos recursos públicos, a utilização da RFID (“Radio Frequency Identification”) surge como elemento que pode trazer benefícios em termos de automação, integridade, velocidade e produtividade à Cadeia de Suprimentos da Marinha do Brasil. Este ensaio realiza uma sucinta apresentação dos componentes de um sistema de RFID, expõe potenciais ganhos operacionais e tem como principal objetivo analisar a viabilidade da aplicação da Tecnologia de Identificação por Rádio Frequência na Supply Chain do Sistema de Abastecimento da Marinha (SAbM), analisando aplicabilidade, vantagens, desvantagens e custos relacionados.

International audience; BACKGROUND: Precise genotyping of the intron 8 poly(TG) and poly(T) tracts of the cystic fibrosis transmembrane conductance regulator (CFTR) gene is of clinical relevance in CFTR pathology. The (TG)(m) locus influences the penetrance of the (T)(5) allele, which may be associated with male infertility by congenital bilateral absence of the vas deferens (CBAVD) or other CFTR-related disorders (CFTR-RD), in particular in the context of (TG)(12) and (TG)(13). Simple and accurate genotyping of both loci should thus be routinely offered in laboratories. METHODS: We designed a new single test method relying on multiplex allele-specific fluorescent PCR: (T)(5)-, (T)(7)-, and (T)(9)-specific primers, labeled with different fluorophores, in combination with a common primer. Each fluorescent PCR product was identified on a capillary sequencer by its fluorescence color, specific for (T)(n), and size, indicative of the (TG) length. We first validated the assay in 2 different laboratories on 52 DNA samples with already known genotypes. We then evaluated the method prospectively, compared with sequencing, on 62 samples from healthy individuals and 108 samples from patients with CBAVD or other CFTR-RDs. RESULTS: We observed a 100% match in both validation steps. Results found in CBAVD and CFTR-RD patients are in keeping with data in the literature. CONCLUSIONS: The assay proved to be simple, rapid, and accurate for single-test (TG)(m)(T)(n) genotyping and suited for analysis in clinical laboratories.

Rapid identification of patients infected with clarithromycin-resistant Helicobacter pylori without the need for culture can help to avoid useless prescriptions of clarithromycin. We developed and tested a routine real-time quantitative PCR assay dedicated to that purpose. One hundred ninety-six consecutive gastric biopsy specimens were examined by culture, histology performed by a trained physician, and rapid PCR with the LightCycler apparatus. Infection was defined as (i) positivity of culture, (ii) positivity of histology, or (iii) positivity of PCR if confirmed by positivity of a concomitant indirect test (serology or urea breath test). Susceptibility to clarithromycin was tested by E-test and PCR. The prevalence of infection was 33.7% (66 of 196 samples). The sensitivities of culture, histology, and PCR were 90.9% (60 of 66 samples), 87.9% (58 of 66 samples), and 97.0% (64 of 66 samples), respectively. The specificity of PCR was 94.6% (123 of 130 samples). The linearity of the PCR results was achieved over a 6-log range of input DNA, and we were able to accurately quantify as few as 300 bacteria and to qualitatively detect as few as 30 bacteria per DNA sample. For clarithromycin susceptibility testing, there was 98.2% (55 of 56 samples) concordance between E-test and PCR. Forty-eight strains were clarithromycin susceptible, and 9 strains were clarithromycin resistant. The single discrepancy concerned a culture which was a mixture of mutant and wild type, with a susceptible-to-resistant ratio of 11.5: the resistant population was detected by E-test but not by PCR. Our PCR assay is accurate for fast detection of H. pylori as well as of clarithromycin resistance and is also able to objectively determine bacterial density.