Rapid aneuploidy testing (knowing less) versus traditional karyotyping (knowing more) for advanced maternal age: What would be missed, who should decide?

Objectives The application of rapid aneuploidy testing as a stand-alone approach in prenatal diagnosis is much debated. The major criticism of this targeted approach is that it will not detect other chromosomal abnormalities that will be picked up by traditional karyotyping. This study aimed to study the nature of such chromosomal abnormalities and whether parents would choose to terminate affected pregnancies. Design Retrospective study on a cytogenetic database. Setting Eight public hospitals in Hong Kong. Participants The karyotype results of 19 517 amniotic fluid cultures performed for advanced maternal age (≥35 years) from 1997 to 2002 were classified according to whether they were detectable by rapid aneuploidy testing. The outcomes of pregnancies with abnormal karyotypes were reviewed from patient records. Results In all, 333 (1.7%) amniotic fluid cultures yielded abnormal karyotypes; 175 (52.6%) of these were detected by rapid aneuploidy testing, and included trisomy 21 (n=94, 28.2%), trisomy 18 or 13 (n=21, 6.3%), and sex chromosome abnormalities (n=60, 18.0%). The other 158 (47.4%) chromosomal abnormalities were not detectable by rapid aneuploidy testing, of which 63 (18.9%) were regarded to be of potential clinical significance and 95 (28.5%) of no clinical significance. Pregnancy outcomes in 327/333 (98.2%) of these patients were retrieved. In total, 143 (42.9%) of these pregnancies were terminated: 93/94 (98.9%) for trisomy 21, 20/21 (95.2%) for trisomy 18 or 13, 19/60 (31.7%) for sex chromosome abnormalities, and 11/63 (17.5%) for other chromosomal abnormalities with potential clinical significance. There were no terminations in the 95 pregnancies in which karyotyping results were regarded to be of no clinical significance. Conclusions 'Knowing less' by the rapid aneuploidy stand-alone testing could miss about half of all chromosomal abnormalities detectable by amniocentesis performed for advanced maternal age. Findings from two fifths of the latter were of potential clinical significance, and the parents chose to terminate one out of six of the corresponding pregnancies. If both techniques are available, parents could have enhanced autonomy to choose.published_or_final_versio

Hypertriton Production in p-Pb Collisions at √sNN = 5.02 TeV

The study of nuclei and antinuclei production has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. The first measurement of the production of ${\rm ^{3}_{\Lambda}\rm H}$ in p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV is presented in this Letter. Its production yield measured in the rapidity interval -1 < y < 0 for the 40% highest multiplicity p-Pb collisions is ${\rm d} N /{\rm d} y =[\mathrm{6.3 \pm 1.8 (stat.) \pm 1.2 (syst.) ] \times 10^{-7}}$. The measurement is compared with the expectations of statistical hadronisation and coalescence models, which describe the nucleosynthesis in hadronic collisions. These two models predict very different yields of the hypertriton in small collision systems such as p-Pb and therefore the measurement of ${\rm d} N /{\rm d} y$ is crucial to distinguish between them. The precision of this measurement leads to the exclusion with a significance larger than 6$\sigma$ of some configurations of the statistical hadronisation, thus constraining the production mechanism of loosely bound states

General balance functions of identified charged hadron pairs of (pi,K,p) in Pb-Pb collisions at 2.76 TeV

First measurements of balance functions (BFs) of all combinations of identified charged hadron ( π , K, p) pairs in Pb–Pb collisions at √sNN = 2.76 TeV recorded by the ALICE detector are presented. The BF measurements are carried out as two-dimensional differential correlators versus the relative rapidity (delta-y) and azimuthal angle (delta-φ) of hadron pairs, and studied as a function of collision centrality. The delta-φ dependence of BFs is expected to be sensitive to the light quark diffusivity in the quark–gluon plasma. While the BF azimuthal widths of all pairs substantially decrease from peripheral to central collisions, the longitudinal widths exhibit mixed behaviors: BFs of π π and cross-species pairs narrow significantly in more central collisions, whereas those of KK and pp are found to be independent of collision centrality. This dichotomy is qualitatively consistent with the presence of strong radial flow effects and the existence of two stages of quark production in relativistic heavy-ion collisions. Finally, the first measurements of the collision centrality evolution of BF integrals are presented, with the observation that charge balancing fractions are nearly independent of collision centrality in Pb–Pb collisions. Overall, the results presented provide new and challenging constraints for theoretical models of hadron production and transport in relativistic heavy-ion collisions

K∗(892)0 and φ(1020) production in p-Pb collisions at √s NN = 8.16 TeV

The production of K*(892)(0) and phi(1020) resonances has been measured in p-Pb collisions at root s(NN) = 8.16 TeV using the ALICE detector. Resonances are reconstructed via their hadronic decay channels in the rapidity interval -0.5 8 GeV/c), the R-pPb values of all hadrons are consistent with unity within uncertainties. The R-pPb of K*(892)(0) and phi(1020) at root s(NN) = 8.16 and 5.02 TeV show no significant energy dependence

Characterizing the initial conditions of heavy-ion collisions at the LHC with mean transverse momentum and anisotropic flow correlations

Correlations between mean transverse momentum and anisotropic flow coefficients or are measured as a function of centrality in Pb–Pb and Xe–Xe collisions at sqrt(sNN) = 5.02 TeV and 5.44 TeV, respectively, with ALICE. In addition, the recently proposed higher-order correlation between [pt], v2, and v3 is measured for the first time, which shows an anticorrelation for the presented centrality ranges. These measurements are compared with hydrodynamic calculations using IP-Glasma and TRENTO initial-state shapes, the former based on the Color Glass Condensate effective theory with gluon saturation, and the latter a parameterized model with nucleons as the relevant degrees of freedom. The data are better described by the IP-Glasma rather than the TRENTO based calculations. In particular, Trajectum and JETSCAPE predictions, both based on the TRENTO initial state model but with different parameter settings, fail to describe the measurements. As the correlations between [pt] and vn are mainly driven by the correlations of the size and the shape of the system in the initial state, these new studies pave a novel way to characterize the initial state and help pin down the uncertainty of the extracted properties of the quark–gluon plasma recreated in relativistic heavy-ion collisions

Inclusive and multiplicity dependent production of electrons from heavy-flavour hadron decays in pp and p-Pb collisions

Measurements of the production of electrons from heavy-flavour hadron decays in pp collisions at root s = 13 TeV at midrapidity with the ALICE detector are presented down to a transverse momentum (p(T)) of 0.2 GeV/c and up to p(T) = 35 GeV/c, which is the largest momentum range probed for inclusive electron measurements in ALICE. In p-Pb collisions, the production cross section and the nuclear modification factor of electrons from heavy-flavour hadron decays are measured in the p(T) range 0.5 < p(T) < 26 GeV/c at root s(NN) = 8.16 TeV. The nuclear modification factor is found to be consistent with unity within the statistical and systematic uncertainties. In both collision systems, first measurements of the yields of electrons from heavy-flavour hadron decays in different multiplicity intervals normalised to the multiplicity-integrated yield (self-normalised yield) at midrapidity are reported as a function of the self-normalised charged-particle multiplicity estimated at midrapidity. The self-normalised yields in pp and p-Pb collisions grow faster than linear with the self-normalised multiplicity. A strong p(T) dependence is observed in pp collisions, where the yield of high-p(T) electrons increases faster as a function of multiplicity than the one of low-p(T) electrons. The measurement in p-Pb collisions shows no p(T) dependence within uncertainties. The self-normalised yields in pp and p-Pb collisions are compared with measurements of other heavy-flavour, light-flavour, and strange particles, and with Monte Carlo simulations

13q - In a fetus with ultrasonographic diagnosis of exencephaly in the first trimester [2]

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Robertsonian translocations (21;21) and (13;13) may not be detected by fluorescence in situ hybridization in uncultured fetal lymphocytes

Poster Presentatio

Prenatal findings and delineation of de novo concurrent partial trisomy 7q(7q31.2 → qter) and partial monosomy 6q(6q26 → qter) by high-resolution array CGH

Objective.We investigated the application of microarray-based comparative genomic hybridization array CGH on a fetus showing hemivertebrae and intra-abdominal mass at 15 weeks. Methods. Conventional karyotyping and high-resolution array CGH techniques using 244K CGH microarray were performed to investigate the possibility of genomic imbalance on the opted chorionic villus sample. Results.G-banded fetal chromosome analysis showed 46,XY,der(6)t(6;7) (q26;q31.2)pat. Whole genome scan by array CGH fine mapped the origin of the aberrant chromosomes to be a partial single copy gain of 42.5 Mb from chromosome region 7:116266547 → qter and concurrent partial single copy loss of 8.1 Mb from chromosome region 6:162756975 → qter. Pathological examination of the abortus showed gastrointestinal malformations, hemivertebrae with scoliosis, clinodactyly and club feet. Conclusions.Prenatal and perinatal findings of concurrent trisomy 7q and monosomy 6q were unique. This study demonstrated array CGH can interrogate the entire genome at a resolution and rapidity unattainable by conventional cytogenetic techniques and may have wide application in prenatal diagnosis. © 2009 Informa Healthcare USA, Inc.link_to_subscribed_fulltex