XY

Distribution by Scientific Domains
Distribution within Life Sciences

Terms modified by XY

  • xy karyotype
  • xy plane

  • Selected Abstracts


    An examination of different fetal specific antibodies and magnetic activated cell sorting for the enrichment of fetal erythroblasts from maternal blood

    CONGENITAL ANOMALIES, Issue 3 2002
    Xiao Xi Zhao
    ABSTRACT, The aim of the present study was to compare the rates of fetal cells obtained after separation from maternal blood by magnetic activated cell sorting (MACS) using different fetal specific antibodies, and to evaluate the potential role of this method in the prenatal diagnosis of fetal trisomies. Peripheral blood samples were obtained from 42 women carrying chromosomally normal fetuses and from 4 women with aneuploid fetuses (2 cases of 47,XX,+18 and 2 of 47,XY,+21) at 9,20 weeks of gestation. After fetal cells were enriched by MACS with three different monoclonal antibodies (GPA, CD71, CD14), fluorescence in situ hybridization (FISH) with chromosome X, and Y-specific probes was performed to detect the rates of fetal cells in the samples sorted. FISH with chromosome 13-, 18-, and 21-specific probes was carried out to compare proportions of cells with three-signal nuclei in chromosomally normal and abnormal groups. In male infants, X-and Y-positive cells were detected in 80%, 73.3%, and 66.6% of samples after the separation by antibodies CD14, GPA, and CD71, respectively. The percentage of nuclei with three signals was increased in pregnancies with trisomy, ranging between 2% and 5.18%. Pregnancies with normal fetuses showed 0 to 3.7% of nuclei with three signals. The data demonstrate that fetal cell detection varies depending on the antibodies used for cell sorting. This study provides further evidence on the feasibility of screening for fetal chromosomal abnormalities by enriching maternal blood for fetal cells and using FISH. [source]


    Generalized Pareto models with application to drought data

    ENVIRONMETRICS, Issue 4 2008
    Saralees Nadarajah
    Abstract Generalized Pareto distributions are some of the most applied distributions in environmental sciences. In this paper, a drought application is described by deriving the exact distributions of the sum X,+,Y, the product XY, and the ratio X/(X,+,Y) when X and Y are independent generalized Pareto random variables. Drought data from the State of Nebraska are used. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    X chromosome number causes sex differences in gene expression in adult mouse striatum

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2009
    Xuqi Chen
    Abstract Previous research suggests that sex differences in the nigrostriatal system are created by direct effects of the sex chromosomes (XX vs. XY), independent of the action of gonadal hormones. Here we tested for sex chromosome effects on expression of three mRNAs in the striatum and nucleus accumbens of adult mice of the four core genotypes model (XX and XY gonadal males, XX and XY gonadal females). Mice were gonadectomized (GDX) at 47,51 days old to eliminate group differences in the levels of gonadal steroids. Three weeks later, mice were killed and brains collected for in situ hybridization of the striatum, or the striatum was dissected out for quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Expression in XX and XY mice was measured by in situ hybridization using riboprobes encoding the dynorphin precursor Pdyn (prodynorphin), the substance P precursor Tac1 (preprotachykinin) or dopamine D2 receptor. XX mice had higher expression, relative to XY mice of the same gonadal sex, of Pdyn and Tac1 mRNA in specific striatal regions. Quantitative PCR confirmed that GDX XX mice have higher Pdyn expression in striatum than XY mice, regardless of their gonadal sex. XX had higher Pdyn expression than XY or XO mice, indicating that the sex chromosome effect is the result of XX vs. XY differences in the number of X chromosomes, probably because of sex differences in the expression of X gene(s) that escape inactivation. We detected no sex chromosome effect on D2 receptor mRNA. [source]


    GENETIC ANALYSIS OF A CHROMOSOMAL HYBRID ZONE IN THE AUSTRALIAN MORABINE GRASSHOPPERS (VANDIEMENELLA, VIATICA SPECIES GROUP)

    EVOLUTION, Issue 1 2009
    Takeshi Kawakami
    Whether chromosomal rearrangements promote speciation by providing barriers to gene exchange between populations is one of the long-standing debates in evolutionary biology. This question can be addressed by studying patterns of gene flow and selection in hybrid zones between chromosomally diverse taxa. Here we present results of the first study of the genetic structure of a hybrid zone between chromosomal races of morabine grasshoppers Vandiemenella viatica, P24(XY) and viatica17, on Kangaroo Island, Australia. Chromosomal and 11 nuclear markers revealed a narrow hybrid zone with strong linkage disequilibrium and heterozygote deficits, most likely maintained by a balance between dispersal and selection. Widths and positions of clines for these markers are concordant and coincident, suggesting that selection is unlikely to be concentrated on a few chromosomes. In contrast, a mitochondrial marker showed a significantly wider cline with centre offset toward the P24(XY) side. We argue that the discordance between the mitochondrial and nuclear/chromosomal clines and overall asymmetry of the clines suggest a secondary origin of the contact zone and potential movement of the zone after contact. Genome-wide scans using many genetic markers and chromosomal mapping of these markers are needed to investigate whether chromosomal differences directly reduce gene flow after secondary contact. [source]


    Effects of sex chromosome aneuploidy on male sexual behavior

    GENES, BRAIN AND BEHAVIOR, Issue 6 2008
    J. H. Park
    Incidence of sex chromosome aneuploidy in men is as high as 1:500. The predominant conditions are an additional Y chromosome (47,XYY) or an additional X chromosome (47,XXY). Behavioral studies using animal models of these conditions are rare. To assess the role of sex chromosome aneuploidy on sexual behavior, we used mice with a spontaneous mutation on the Y chromosome in which the testis-determining gene Sry is deleted (referred to as Y,) and insertion of a Sry transgene on an autosome. Dams were aneuploid (XXY,) and the sires had an inserted Sry transgene (XYSry). Litters contained six male genotypes, XY, XYY,, XXSry, XXY,Sry, XYSry and XYY,Sry. In order to eliminate possible differences in levels of testosterone, all of the subjects were castrated and received testosterone implants prior to tests for male sex behavior. Mice with an additional copy of the Y, chromosome (XYY,) had shorter latencies to intromit and achieve ejaculations than XY males. In a comparison of the four genotypes bearing the Sry transgene, males with two copies of the X chromosome (XXSry and XXY,Sry) had longer latencies to mount and thrust than males with only one copy of the X chromosome (XYSry and XYY,Sry) and decreased frequencies of mounts and intromissions as compared with XYSry males. The results implicate novel roles for sex chromosome genes in sexual behaviors. [source]


    Aneuploidy in spermatozoa of infertile men with teratozoospermia

    INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 4 2001
    Kati HÄrkönen
    Recent studies have shown that aneuploidy in spermatozoa of infertile men with poor semen quality is increased. The purpose of this study was to determine whether poor sperm morphology is associated with the incidence of spermatozoa with numerical chromosome abnormalities. Semen samples from 20 infertile teratozoospermic men were studied using multicolour fluorescence in situ hybridization (FISH). Men were divided into four groups according to the proportion of normal sperm morphology: infertile men with <10% (group A, n=7), 10,19% (group B, n=6), and 20,29% (group C, n=7) of morphologically normal spermatozoa, and controls (group D, n=5) with ,30% normal forms. Two hybridizations were performed. All the samples were analysed using probes for chromosomes 1 and 7 and, in addition, in group A and in controls with normal semen parameters probes for chromosomes X, Y and 18 were also used. Ten thousand spermatozoa were scored per hybridization. Severely teratozoospermic men (<10% normal forms) had significantly higher frequency of disomy 7, 18, YY, XY and diploidy in their spermatozoa when compared with controls. The results suggest that poor sperm morphology is associated with numerical chromosome abnormalities of spermatozoa. Severely teratozoospermic men may be at an increased risk of producing aneuploid offspring. [source]


    Kinetics and mechanism of the reaction of para -chlorophenyl aryl chlorophosphates with anilines in acetonitrile

    INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 11 2002
    Hai Whang Lee
    The kinetics and mechanism of the nucleophilic substitution reactions of p -chlorophenyl aryl chlorophosphates (2) with anilines are investigated in acetonitrile at 55°C. Relatively large magnitudes of ,X and ,X values are indicative of a large degree of bond making in the TS. Smaller magnitudes of ,X (0.20 for X = H) and ,XY (,0.30) than those for the corresponding reactions with phenyl aryl chlorophosphates (1) (,X = 0.54 for X = H and ,XY = ,1.31) are interpreted to indicate partial electron loss, or shunt, towards the electron acceptor equatorial ligand (p -ClC6H4O-) in the bipyramidal pentacoordinated transition state. The inverse secondary kinetic isotope effects (kH/kD = 0.64,0.87) involving deuterated aniline (ND2C6H4X) nucleophiles, and small ,H, and large negative ,S, are obtained. These results are consistent with a concerted nucleophilic substitution mechanism. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 632,637, 2002 [source]


    Atomic-orbital-symmetry based ,-, ,-, and ,-decomposition analysis of bond orders

    INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 11 2009
    Olga V. Sizova
    Abstract The atomic-orbital-symmetry based (AOSB) scheme for the decomposition of Mayer and Wiberg bond orders into ,-, ,-, and ,-components is used to investigate different types of covalent bonds. Four series of compounds are studied: simple molecules with homonuclear bonds, inorganic molecules with polar heteronuclear bonds, [Ru(CN)5(XY)]q transition metal complexes with ,-acceptor ligands, and dimetal complexes with multiple metal,metal bonds. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source]


    Differential strength of sex-biased hybrid inferiority in impeding gene flow may be a cause of Haldane's rule

    JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 2 2003
    Ren-Xue Wang
    Abstract In animals, if one sex of the F1 hybrid between two species is sterile or inviable, it is usually the heterogametic (XY or WZ) sex. This phenomenon, known as Haldane's rule, is currently thought to be coincidentally caused by different mechanisms in separate entities. The following questions have never been asked: Are heterogametic and homogametic inferiority (sterility or inviability) equivalent as isolating mechanisms? Could discrepancies between them, if existing, produce Haldane's rule? Here I consider sex-biased hybrid inferiority strictly as an isolating mechanism, and quantitatively evaluate its strength in impeding gene flow. The comparison reveals that the ability of sex-biased inferiority to impede gene flow varies according to the sex and chromosome involved. Heterogametic inferiority is a weaker barrier when unidirectional and a much stronger one when in compound reciprocal directions, compared with homogametic inferiority. Such differential strength may affect divergence in speciation and produce Haldane's rule. [source]


    UV laser-induced desorption mechanism analyzed through two-layer alkali halide samples

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 5 2008
    F. A. Fernández-Lima
    Abstract Time of flight-mass spectrometry (TOF-MS) is used to analyze positive and negative desorbed ions generated by UV laser ablation of several alkali (X) halide (Y) salts. Most of the observed desorbed cluster ions have the structure (XY)nX+ or (XY)nY,. Their desorption yields decrease as exp(,kn), where k , 2 for both series, suggesting that the neutral component (XY)n plays the dominant role in the desorption process. Mass spectrum measurements were performed for compound samples in which two salts (out of CsI, RbI, KBr, KCl and KI) are homogeneously mixed or disposed in two superposed layers. The detection of small new ion species and large cluster ions of the original salts supports the scenario that the uppermost layers are completely atomized while deep layers are emitted colder and fragmented: It is proposed that ns-pulsed laser induced desorption of ionic salts occurs via two sequential mechanisms: (1) ejection of cations and anions in the hot plume, followed by recombination into new cluster ions and (2) ejection of relatively cold preformed species originated from deep layers or from periphery of the irradiated region. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Preparation and characterization of soluble terpolymers from m -phenylenediamine, o -anisidine, and 2,3-xylidine

    JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2001
    Xin-Gui Li
    Abstract A series of terpolymers were synthesized by the chemical oxidative polymerization of m -phenylenediamine (MPD), o -anisidine (AS), and 2,3-xylidine (XY) in hydrochloride aqueous medium. The yield, intrinsic viscosity, and solubility of the terpolymers were studied by changing the MPD/AS/XY molar ratio from 100/0/0 to 53/39/8 to 0/100/0. It was discovered that the MPD/AS/XY terpolymers exhibit a higher polymerization yield and better solubility than MPD/AS and MPD/XY bipolymers having the same MPD molar content. The as-prepared MPD/AS/XY terpolymer bases were characterized by Fourier transform infrared, ultraviolet,visible, 1H NMR, and high-resolution solid-state 13C NMR spectroscopies; wide-angle X-ray diffraction; and thermogravimetry. The results suggested that the oxidative polymerization from MPD, AS, and XY is exothermic, and the resulting terpolymers are more easily soluble in some organic solvents than MPD homopolymer. The copolymer obtained was a real terpolymer containing MPD, AS, and XY units, and the actual MPD/AS/XY molar ratio calculated by solid-state 13C NMR spectra of the polymers is very close to the feed ratio, although the AS content calculated on the basis of the 1H NMR spectrum of the soluble part of the polymer is higher than the feed AS content. The terpolymers and MPD homopolymer exhibit a higher polymerization yield and much higher intrinsic viscosity and are more amorphous than the AS homopolymer. At a fixed MPD content of 70 mol %, the terpolymers exhibit an increased thermostability and activation energy of the major degradation in nitrogen and air with an increasing AS content. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3989,4000, 2001 [source]


    XY chromosomal bivalent: Nucleolar attraction

    MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2005
    Laura L. Tres
    Abstract Nucleolar organization by autosomal bivalents occurs during male meiotic prophase in mammalian species. During late leptotene,early zygotene stages, several autosomal bivalents are engaged in ribosomal RNA synthesis. At pachytene stage, nucleolar masses detach from the sites of primary autosomal origin, relocate close to the XY chromosomal pair, and nucleolar components become segregated. In early pachytene, an extensive synaptonemal complex at the pseudoautosomal region, links X and Y chromosomes in close juxtaposition along most of the length of the Y chromosome, except for a terminal region of the Y that diverges from the pairing region. As meiotic prophase advances, X and Y chromosomes progressively desynapse and, at diplotene, the XY pair is associated end-to-end. Xmr (Xlr-related, meiosis regulated) is a protein component of the nucleolus associated to the XY pair and of the asynapsed portions of the X and Y axial cores. Xmr, like SCP3, is a component of the lateral element of the synaptonemal complex. Both share structural homology in their C-terminal region. This region contains several putative coiled-coil domains known to mediate heterodimeric protein,protein interactions and to provide binding sites to regulatory proteins. Like Xmr, the tumor repressor protein BRCA1 is present along the unsynapsed cores of the XY bivalent. Both Xmr and BRCA1 have been implicated in a mechanism leading to chromatin condensation and transcription inactivation of the XY bivalent. The BRCA1-ATR kinase complex, as recent research suggests, triggers the phosphorylation of histone H2AX, which predominates in the condensed chromatin of the XY chromosomal pair. Xmr is not present in the XY bivalent when the expression of histone H2AX is deficient. The role of Xmr in chromatin condensation of the XY bivalent has not been determined. The partial structural homology of SCP3 and Xmr, their distribution along the unsynapsed axial cores of the X and Y chromosomes, and the presence of Xmr in the XY pair-associated nucleolus raises the possibility that Xmr, and other proteins including protein kinases, may be recruited to the nucleolus to perform functions related to chromosomal synapsis, chromatin condensation and recombination processes, as well as cell cycle progression. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source]


    Clonal complex chromosome aberration in non-ossifying fibroma,

    PEDIATRIC BLOOD & CANCER, Issue 5 2010
    María Sol Brassesco PhD
    Abstract Cytogenetic information of non-ossifying fibromas (NOFs) is exceptionally limited. This fact relies, in part, on their benign nature but mainly because most cases evolve undetected or there is no need for surgical intervention. We report the case of a NOF arising in the left tibia of a 14-year-old male with an invariable clonal translocation. The karyotype was denoted as 42,46,XY,t(11;3;14)(q23;p21;p11). There are only two previous reported cases of clonally aberrant NOF. Records from additional cases will be essential to assess whether consistent karyotypic aberrations define this lesion. Pediatr Blood Cancer 2010;54:764,767. © 2010 Wiley-Liss, Inc. [source]


    Field-induced effects in the S = 1 two-dimensional Heisenberg antiferromagnet

    PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 10 2005
    M. E. Gouvêa
    Abstract We use the self-consistent harmonic approximation to study the spin S = 1 Heisenberg antiferromagnet on a two-dimensional lattice in a uniform applied magnetic field. The magnetic field destroys the ,,(3) symmetry and an XY -like behavior, with a Berezinskii,Kosterlitz,Thouless (BKT) transition, is expected. We obtain the field dependence of the transition temperature for fields varying in a wide range. There has been experimental evidence that, for low dimensional spin systems, a gap can be induced by the applied magnetic field. We also investigate the behavior of this field-induced gap. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Monochorionic-diamniotic twins discordant in gender from a naturally conceived pregnancy through postzygotic sex chromosome loss in a 47,XXY zygote

    PRENATAL DIAGNOSIS, Issue 8 2008
    Nicolas H. Zech
    Abstract Objective It is generally believed that monochorionic-diamniotic twin pregnancies result from one fertilized oocyte with both siblings having the same genotype and phenotype. In rare instances, due to somatic mutations or chromosome aberrations, the karyotypes and phenotypes of the two twins can differ. Method We report cytogenetic, molecular genetic and clinical examinations in monochorionic-diamniotic twins discordant in gender. Results The monochorionic-diamniotic status of the twins was diagnosed by ultrasound and histologic examination of the placenta. Prenatal chromosome examination performed on amniocytes revealed a normal female karyotype in one and a 46,XX(26)/46,XY(3) karyotype in the other twin. Molecular examinations confirmed monozygosity despite discordant sex. Based on the cytogenetic and molecular results of lymphocytes and placental cells, the only explanation for gender discordance was that the conceptus originally had a 47,XXY chromosome complement. Conclusion A 47,XXY zygote appears to have undergone a twinning process. A postzygotic loss of the X chromosome in some cells and the Y chromosome in other cells, either before or after twinning, resulted in 46,XX/46,XY mosaicism in both monozygotic (MZ) twins. The sex discordance of the MZ twins can be explained by different proportions of the 46,XX and 46,XY cell lines in the gonads and other tissues. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Prenatal diagnosis of a fetus with androgen insensitivity syndrome (AIS)

    PRENATAL DIAGNOSIS, Issue 9 2007
    Ahmet Yalinkaya
    Abstract Objective The aim of this study is to describe a fetus with androgen insensitivity syndrome diagnosed at mid-second trimester. Case and Methods Nuchal translucency was measured thick and double test was found higher. The patient referred to our center at 16th weeks of gestation. Fetal ultrasound examination and amniocentesis was performed. Results The nuchal translucency (NT) of fetus in present pregnancy was measured approximately 10 mm at 13 weeks and Down syndrome risk was calculated 1 in 10 by double test. On ultrasound examination; thick nuchal fold (NF) and short fetal limbs were found, and the fetus was seen a female and amniocentesis was performed. Three weeks later the fetal karyotype was reported normal as 46,XY. Thereupon the fetus reexamined for 2D and 4D ultrasound, and confirmed previous findings. The fetus was terminated at 19th weeks and seen a female phenotype. The fetal gonads removed in abdomen and testicles confirmed histopatologically. Conclusion In generally, diagnosis of AIS is most made postnatally. This is the second case in English literature, which diagnosed mid-second trimester. In this situation, the fetus with thick NT/NF and short limbs may be AIS, therefore appearance of fetal sex on ultrasound should be compared with genetic sex Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Parental mosaic trisomy 21 detected following maternal cell contamination of an amniotic fluid specimen from a normal male pregnancy

    PRENATAL DIAGNOSIS, Issue 9 2007
    Melissa L. Street
    Abstract We report a case of maternal mosaic trisomy 21 ascertained at prenatal diagnosis as a result of maternal cell contamination of an amniotic fluid sample. A 34 year old female was referred for karyotyping because of a previous trisomy 21 pregnancy. Chromosome analysis of primary in situ cultures showed a karyotype of 47,XX, + 21[6]/46,XY[32]/46,XX[2]. Molecular testing demonstrated maternal cell contamination of the amniotic fluid sample and G-banded karyotyping of maternal blood showed that 3/200 cells had trisomy 21, consistent with the mother being a Down syndrome mosaic. A normal male baby with a 46,XY chromosome complement was delivered at 30 weeks. This case emphasises the need for close collaboration between cytogenetic and molecular genetics laboratories in resolving unusual cases of mosaicism. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Semilobar holoprosencephaly prenatal diagnosis: an unexpected complex rearrangement in a de novo apparently balanced reciprocal translocation on karyotype

    PRENATAL DIAGNOSIS, Issue 3 2007
    S. Kanafani
    Abstract We report a semilobar holoprosencephaly (HPE) in a post-intracytoplasmic-sperm-injection pregnancy. It was suggested by ultrasonography (US), documented on karyotype, identified with magnetic resonance imaging (MRI), established after birth and confirmed on post-mortem autopsy. An amniocentesis revealed a de novo apparently balanced reciprocal translocation 46,XY, t(7;8) (q31.3;q12). Fluorescence in situ hybridization (FISH) identified a deletion in the region of the Sonic Hedgehog gene (SHH) on der(8); nevertheless, the subtelomeric regions for chromosomes 7 and 8 were present. The parents decided to continue the pregnancy; a boy was born and survived for 3 days. The brain autopsy confirmed the semilobar HPE previously noted on US and MRI. Further, band-specific FISH revealed, in addition to SHH deletion, the presence of an inversion in the 7q translocated material on der(8). The parents' karyotypes were normal. An unexpected complex rearrangement was present in a de novo apparently balanced reciprocal translocation in a semilobar HPE. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Perinatal findings and molecular cytogenetic analyses of de novo interstitial deletion of 9q (9q22.3,q31.3) associated with Gorlin syndrome

    PRENATAL DIAGNOSIS, Issue 8 2006
    Chih-Ping Chen
    Abstract Objectives To present the perinatal findings and the molecular cytogenetic analyses of a de novo interstitial deletion of 9q (9q22.3,q31.3) associated with Gorlin syndrome. Methods Amniocentesis was performed at 18 weeks' gestation on a 27-year-old woman at a community hospital because of a high Down syndrome risk of 1/178, a low maternal serum ,-fetoprotein (MSAFP) level of 0.66 multiples of the median (MoM), and a high maternal serum human chorionic gonadotrophin (MShCG) level of 3.13 MoM. The karyotype was initially determined to be 46,XY. However, fetal macrocephaly and overgrowth were found at 30 weeks' gestation. Postnatally, the infant manifested characteristic features of Gorlin syndrome. High-resolution chromosomal bandings of the peripheral blood lymphocytes, polymorphic DNA marker analysis to determine the parental origin of the deletion, array comparative genomic hybridization (CGH) to determine the extent of the chromosomal deletion, and fluorescence in situ hybridization (FISH) to determine the deletion of the PTCH gene were performed. Results The 850-band level of resolution showed an interstitial deletion of 9q (9q22.3,q31.3). The parental karyotypes were normal. The karyotype of the proband was 46,XY,del(9)(q22.3q31.3)de novo. Polymorphic DNA marker analysis revealed that the deletion was of paternal origin. Array CGH revealed that the deleted region was about 12 Mb, encompassing the segment from 9q22.32 to 9q31.3. FISH analysis using the BAC probe RP11-34D4 and the probe RP11-43505 indicated the deletion of the PTCH gene. Conclusions Fetuses with an interstitial deletion of 9q (9q22.3,q31.3) may be associated with a low level of MSAFP and a high level of MShCG in the second trimester, and sonographic findings of overgrowth and macrocephaly in the third trimester. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Prenatal diagnosis of de novo t(2;18;14)(q33.1;q12.2;q31.2), dup(5)(q34q34), del(7)(p21.1p21.1), and del(10)(q25.3q25.3) and a review of the prenatally ascertained de novo apparently balanced complex and multiple chromosomal rearrangements

    PRENATAL DIAGNOSIS, Issue 2 2006
    Chih-Ping Chen
    Abstract Objectives To present the prenatal diagnosis of a de novo complex chromosomal rearrangement (CCR) associated with de novo interstitial deletions and duplication and to review the literature. Case and Methods Amniocentesis was performed at 18 weeks' gestation because of an increased risk for Down syndrome based on maternal serum ,-fetoprotein and human chorionic gonadotrophin screening. Amniocentesis revealed a karyotype of 46,XY,t(2;18;14)(q33.1;q12.2;q31.2),dup(5)(q34q34),del(7)(p21.1p21.1), del(10)(q25.3q25.3). The parental karyotypes were normal. The pregnancy was terminated. The fetus manifested facial dysmorphism, clinodactyly of both hands, and hypoplasia of the left great toe. Spectral karyotyping (SKY), cytogenetic polymorphism, and polymorphic DNA markers were used to investigate the imbalances and the origin of the de novo aberrant chromosomes. Results SKY showed a three-way CCR. Cytogenetic polymorphism investigation of the derivative chromosome 14 of the fetus and the parental chromosomes 14 determined the maternal origin of the translocation. Polymorphic DNA marker analysis confirmed the maternal origin of the de novo interstitial deletions and duplication. No cryptic imbalance at or near the breakpoints of the CCR was detected by the molecular analysis. Conclusions De novo apparently balanced CCRs may be associated with imbalances in other chromosomes. We suggest further investigation and re-evaluation of cryptic or subtle imbalances in all cases classified as de novo apparently balanced CCRs. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Prenatal diagnosis of jumping translocation involving chromosome 22 with ultrasonographic findings

    PRENATAL DIAGNOSIS, Issue 11 2005
    Halil Aslan
    Abstract We report on the prenatal diagnosis and ultrasonographic findings of a second-trimester fetus with jumping translocation involving chromosome 22. A 28-year-old gravida 2, partus 1, Turkish woman was referred for genetic counselling and ultrasonographic examination at 18 weeks' gestation because of a high risk of trisomy 21 in triple test. Prenatal ultrasonography showed tetralogy of Fallot with a diverticular dilatation of the pulmonary artery, flattened brow, complete absence of the right upper limb, hypospadias, oligodactyly (three digits) in left hand and in both feet, and hyperechogenic abdominal foci. Amniocentesis revealed a karyotype of 46,XY[4]/46,XY,,8,+ der(8),t(8;22)(q24.3;q11.21)[2]/45, XY,,22,,8,+ der(8)t(8;22)(q24.3;q11.21)[22]/45,XY,,22,,5,+ der(5)t(5;22)(q35.3;q11.21)[44]. A C-banding and FISH study with a specific centromeric probe (D14Z1/D22Z1) for chromosome 22 was made. In our case, partial monosomy for the regions 22q11.21,22pter, 8q24.3,8qter and 5q35.3,5qter may partially explain the fetal malformations. Copyright © 2005 John Wiley & Sons, Ltd. [source]


    Prenatal diagnosis and molecular cytogenetic analysis of partial monosomy 10q (10q25.3,qter) and partial trisomy 18q (18q23,qter) in a fetus associated with cystic hygroma and ambiguous genitalia

    PRENATAL DIAGNOSIS, Issue 6 2005
    Chih-Ping Chen
    Abstract Objectives To present the prenatal diagnosis and molecular cytogenetic analysis of a fetus with nuchal cystic hygroma and ambiguous genitalia. Case and Methods Amniocentesis was performed at 16 weeks' gestation because of the abnormal fetal sonographic finding of a large septated nuchal cystic hygroma. Genetic amniocentesis revealed a terminal deletion in the long arm of chromosome 10. The paternal karyotype was subsequently found to be 46,XY,t(10;18)(q25.3;q23). The maternal karyotype was normal. The pregnancy was terminated. A hydropic fetus was delivered with a septated nuchal cystic hygroma and ambiguous genitalia. Fluorescence in situ hybridization (FISH), microarray-based comparative genomic hybridization (CGH), and polymorphic DNA markers were used to investigate the involved chromosomal segments. Results FISH study showed absence of the 10q telomeric probe and presence of the 18q telomeric probe in the derivative chromosome 10. Microarray-based CGH analysis showed loss of distal 10q and gain of distal 18q. Polymorphic DNA marker analysis determined the breakpoints. The fetal karyotype was 46,XY,der(10)t(10;18)(q25.3;q23)pat. The chromosome aberration resulted in partial monosomy 10q (10q25.3,qter) and partial trisomy 18q (18q23,qter). Conclusions The present case provides evidence that partial monosomy 10q (10q25.3,qter) with partial trisomy 18q (18q23,qter) can be a genetic cause of fetal cystic hygroma and ambiguous genitalia. Cytogenetic analysis for prenatally detected structural abnormalities may detect unexpected inherited chromosome aberrations. Copyright © 2005 John Wiley & Sons, Ltd. [source]


    Prenatal diagnosis of tetrasomy 9p with Dandy,Walker malformation

    PRENATAL DIAGNOSIS, Issue 8 2004
    Markus Hengstschläger
    Abstract Objectives To add to the knowledge of chromosomal abnormalities associated with Dandy,Walker malformation. Methods Molecular cytogenetic analyses of a chorionic villus sampling and of an amniocentesis of a fetus with Dandy,Walker malformation and abnormal somatic development. Results All cells examined showed a 47, XY, +idic(9p)(pter,q12::q12,pter) de novo karyotype. This report describes the fourth case of a tetrasomy 9p associated with Dandy,Walker malformation Conclusions This case, together with the three previously reported cases of an association with a tetrasomy 9p, indicate that this chromosomal aberration should be looked for when Dandy,Walker malformation is detected via prenatal ultrasonography. Copyright © 2004 John Wiley & Sons, Ltd. [source]


    Possible human chimera detected prenatally after in vitro fertilization: a case report

    PRENATAL DIAGNOSIS, Issue 11 2003
    B. Simon-Bouy
    Abstract Background Chimerism is the coexistence of more than one cell line in an individual, due to the fusion of originally separate zygotes. It has been very rarely described in humans. Methods A 36-year-old woman who was referred for in vitro fertilization (IVF) for unexplained infertility had three embryos transferred. Results Four weeks and five days after the transfer, ultrasound examination detected a single fetus in the uterus. Ultrasound examination at 17 weeks for metrorrhagia showed severe intrauterine growth retardation. Amniocentesis revealed a mixture of 46,XY and 46,XX clones. Histopathologic examination showed a dysmorphic fetus with female phenotype and severe growth retardation. Conclusions Although demonstration by fingerprinting has not been possible, fusion of two of the three transferred embryos (one male and one female) seems to be the most probable mechanism that could explain both cytogenetic and histopathologic observations. No chimera has yet been described after IVF. It would be interesting to collect any such observations from other IVF centers. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Three different origins for apparent triploid/diploid mosaics

    PRENATAL DIAGNOSIS, Issue 7 2003
    Art Daniel
    Abstract Four apparent triploid/diploid mosaic cases were studied. Three of the cases were detected at prenatal diagnosis and the other was of an intellectually handicapped, dysmorphic boy. Karyotypes were performed in multiple tissues if possible, and the inheritance of microsatellites was studied with DNA from fetal tissues and parental blood. Non-mosaic triploids have a different origin from these mosaics with simple digyny or diandry documented in many cases. Three different mechanisms of origin for these apparent mosaics were detected: (1) chimaerism with karyotypes from two separate zygotes developing into a single individual, (2) delayed digyny, by incorporation of a pronucleus from a second polar body into one embryonic blastomere, and (3) delayed dispermy, similarly, by incorporation of a second sperm pronucleus into one embryonic blastomere. In three of the four cases, there was segregation within the embryos of triploid and diploid cell lines into different tissues from which DNA could be isolated. In case 2 originating by digyny, the same sperm allele at each locus could be detected in both triploid and diploid tissues, which is supportive evidence for the involvement of a single sperm and for true mosaicism rather than chimaerism. Similarly, in case 4 originating by dispermy, the same single ovum allele at each locus could be detected in diploid and triploid tissues, confirming mosaicism. In the chimaeric case (case 3), the diploid line had the karyotype 47,XY,+16 while the triploid line was 69,XXY. This suggests a chimaera, since, in a true mosaic, the triploid line should also contain the additional chromosome 16. Supporting the interpretation of a chimaeric origin for this case, the DNA data showed that the triploidy was consistent with MII non-disjunction (i.e. involving a diploid ovum). In the mosaic cases (1, 2, 4), there was no evidence of the involvement of a diploid sperm or a diploid ova, and in triploid/diploid mosaicism, an origin from a diploid gamete is excluded, since all such conceptuses would be simple triploids. In one of these triploid/diploid mosaics detected at prenatal diagnosis by CVS, the triploid line seemed to be sequestered into the extra-fetal tissues (confined placental mosaicism). This fetus developed normally and a normal infant was born with no evidence of triploidy in newborn blood or cord blood at three months of age. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    A further case of confined placental mosaicism for trisomy 2 associated with adverse pregnancy outcome

    PRENATAL DIAGNOSIS, Issue 7 2003
    Eileen Roberts
    Abstract Objectives To add to the knowledge base concerning confined placental mosaicism for trisomy 2. Methods Cytogenetic study of a late CVS referred for hyperechogenic bowel and raised AFP, and cytogenetic and molecular genetic study of a follow-up amniocentesis. Ultrasound monitoring at regular intervals following the CVS result. Results All cells examined from direct and cultured CVS showed a 47,XY,+2 karyotype. Amniocentesis showed a mosaic 47,XY,+2[8]/46,XY[81] karyotype. Uniparental disomy (UPD) studies on the amniotic fluid showed normal biparental inheritance. The pregnancy developed oligohydramnios and IUGR and resulted in a 26-week liveborn male infant with a 46,XY karyotype, which died after 3 days because of complications of severe prematurity. Placental villi post delivery showed only the 47,XY,+2 cell line. Conclusions This case represents a further example of confined placental mosaicism (CPM) for trisomy 2 associated with oligohydramnios, IUGR and poor pregnancy outcome. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Prenatal diagnosis of the Dandy-Walker malformation and ventriculomegaly associated with partial trisomy 9p and distal 12p deletion

    PRENATAL DIAGNOSIS, Issue 12 2002
    Chih-Ping Chen
    Abstract Objectives To present the prenatal diagnosis and perinatal findings of partial trisomy 9p and distal 12p deletion. Methods and results Amniocentesis was performed at 17 gestational weeks due to a balanced reciprocal translocation t(9;12)(p11.2;p13.3) in the mother. The father's karyotype was normal. The family had a 5-year-old daughter with a Dandy-Walker malformation and a trisomy 9p syndrome. Cytogenetic analysis of the cultured amniotic fluid cells revealed a 46,XY,der(12)t(9;12)(p11.2;p13.3)mat karyotype with partial monosomy 12p(12pter,p13.3) and partial trisomy 9p(9pter,p11.2). Sonographic examination of the fetal brain and skull showed bilateral ventriculomegaly, brachycephaly and a Dandy-Walker malformation with an enlarged cisterna magna and absence of the cerebellar vermis. The pregnancy was terminated subsequently. At autopsy, the proband manifested agenesis of the cerebellar vermis and a typical trisomy 9p phenotype. Conclusion Fetuses with partial trisomy 9p(9pter,p11.2) may present a Dandy-Walker malformation and ventriculomegaly on prenatal ultrasound in the second trimester. A dosage effect of genes located on 9pter,p11.2 may be associated with the abnormal development of the central nervous system in patients with partial or complete trisomy 9. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Prenatal diagnosis of a fetus with pure partial trisomy 1q32-44 due to a familial balanced rearrangement

    PRENATAL DIAGNOSIS, Issue 11 2002
    n Kímya
    Abstract We diagnosed a pure partial trisomy of the long arm of chromosome 1 in a fetus with multiple malformations detected prenatally. The father was a carrier of a balanced rearrangement involving 46,XY,inv(1)(qter,p36::q32,qter::p36,q32). The fetus had preaxial polydactyly, low-set ears, macrocephaly, a prominent forehead, a broad and flat nasal bridge, a small mouth, an arched palate, micrognathia and unilateral renal agenesis. The couple had previously an infant with the same phenotypic abnormalities. The aberration was initially detected on amniocentesis with GTG banding and was confirmed by fluorescence in situ hybridization (FISH). Our case and other published pure trisomy 1q32-44 cases showed similarities, which allowed the further delineation of the trisomy 1q syndrome. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Maternal uniparental isodisomy 10 and mosaicism for an additional marker chromosome derived from the paternal chromosome 10 in a fetus

    PRENATAL DIAGNOSIS, Issue 5 2002
    Monika Schlegel
    Abstract An Erratum has been published for this article in Prenatal Diagnosis 22(11) 2002: 1056. We report a case of maternal isodisomy 10 combined with mosaic partial trisomy 10 (p12.31-q11.1). Chromosome examinations from a CVS sample showed a karyotype 47,XY,+mar/46,XY. The additional marker chromosome which was present in 6/25 interphase nuclei was shown by fluorescence in situ hybridization (FISH) to have been derived from a pericentromeric segment of chromosome 10. DNA analysis was performed from umbilical cord blood from the fetus after termination of the pregnancy at 18 weeks. The results showed that the two structurally normal chromosomes 10 were both of maternal origin, whereas the marker chromosome derived from the father. Autopsy of the fetus revealed hypoplasia of heart, liver, kidneys and suprarenal glands, but, apart from a right bifid ureter, no structural organ abnormalities. This fetus represents the second reported instance of a maternal uniparental disomy (UPD) 10. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Prenatal diagnosis of partial tetrasomy 14: a case study

    PRENATAL DIAGNOSIS, Issue 2 2002
    Alice M. George
    Abstract Prenatal specimens were received from a fetus with abnormalities noted on ultrasound. A supernumerary marker chromosome (SMC) was detected: 47,XY,+mar. Fluorescence in situ hybridisation (FISH) further classified this to be partial tetrasomy for chromosome 14. We compare this finding with other cases of SMC (14) and further classify phenotype with karyotype. Copyright © 2002 John Wiley & Sons, Ltd. [source]