bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simple, rapid, and highly informative PCR‐based procedure for prenatal diagnosis and carrier screening of phenylketonuria
Authors: Eisensmith Randy C. , Goltsov Alexei A. , Woo Savio L. C. 
Published: March 2007

AbstractThe polymorphic information content (PIC) and the degree of heterozygosity of several polymorphic systems within the phenylalanine hydroxylase (PAH) gene were determined in 85 European Caucasian and 19 Chinese phenylketonuria (PKU) kindreds. The first system examined, a short tandem repeat (STR), had a PIC of 80 and 73 per cent in these Caucasian and Chinese samples, respectively. The degree of heterozygosity actually observed for this system was 81 and 64 per cent in the Caucasian and Chinese PKU families, respectively. Through the addition of a second polymorphism based on a variable number of tandem repeats (VNTR), the PIC was increased to 90 per cent in Caucasians, but only to 75 per cent in Chinese. The degree of heterozygosity observed for this combination was 94 per cent in European PKU families and 67 per cent in Chinese PKU families. The further addition of an Xmnl RFLP increased both the PIC and the level of heterozygosity in Caucasians to 95 per cent, but did not change either of these measures in Chinese. The combined use of these three polymorphisms significantly increases the informativity of prenatal diagnostic and carrier screening procedures in both Caucasian and Chinese PKU kindreds. Furthermore, since each of these polymorphisms can be studied by PCR‐based methods, these new tests can be performed more quickly and easily than previous Southern‐based procedures.
Fetal choroid plexus cysts and trisomy 18: Assessment of risk based on ultrasound findings and maternal age
Authors: Snijders Rosalinde J. M. , Shawa Luma , Nicolaides Kypros H. 
Published: March 2007

AbstractThis paper examines the association between fetal choroid plexus cysts (CPCs) and trisomy 18 and proposes a method by which risks can be derived taking into account both sonographic findings and maternal age. Data from our centre on the sonographic findings of 58 fetuses with trisomy 18 and 387 fetuses with CPCs as well as data from published series were used. It was calculated that the prevalence of CPCs in the general population is approximately 1 per cent and at mid‐gestation the incidence of CPCs in fetuses with trisomy 18 is approximately 50 per cent. In the 387 fetuses with CPCs, the incidence of trisomy 18 increased with maternal age and the likelihood ratio for trisomy 18 increased with the number of additional abnormalities, from 0·03 for those with isolated CPCs to 0·4 if there was one additional abnormality and 20·5 if there were two or more additional abnormalities. It was concluded that if the cysts are apparently isolated, the risk for trisomy 18 is only marginally increased and maternal age should be the main factor in deciding whether or not to offer fetal karyotyping. If one additional abnormality is found, the maternal age‐related risk is increased, so that even for a 20‐year‐old the risk for trisomy 18 is at least as high as the risk for trisomy 21 in a 35‐year‐old. In this respect, it may be considered desirable to offer such patients the option of karyotyping.
Flow cytometric method to measure urea‐resistant alkaline phosphatase from blood neutrophils for use in the prenatal screening of Down's syndrome
Authors: Agrawal Yash P. , Ylikangas Päivi , Parviainen Markku T. , Penttilä Ilkka M. 
Published: March 2007

AbstractThe histochemical measurement of urea‐resistant alkaline phosphatase from maternal blood neutrophils is known to have a high detection rate for the prenatal detection of Down's syndrome pregnancies. However, because the histochemical method is laborious and subjective to use, it has not gained widespread acceptance in prenatal screening programmes. We present a simple and objective method for the measurement of urea‐resistant alkaline phosphatase by flow cytometry. The method should allow the design of larger studies aimed at evaluating the role of neutrophil urea‐resistant alkaline phosphatase in the prenatal screening for Down's syndrome.
Chromosome preparations of both direct and long‐term cultures from the same fragment of chorionic villi
Authors: Dawson J. M. , Griffiths M. J. 
Published: March 2007

AbstractA simplified method is described for processing both direct preparations and long‐term cultures from the same fragment of chorionic villi. Enzyme separation of the outer trophoblast layers (used for direct preparations) from the inner mesenchymal core (used to initiate long‐term cultures) facilitates the utilization of the same fragments for the two procedures, without jeopardizing the success of either method. This has proved useful in cases where the sample was so small that only one method of chromosome preparation may have been possible using other techniques.
Prenatal detection of congenital hypospadias in the wolf‐hirschhorn (4p —) syndrome
Authors: Viñals Fernando , Sepulveda Waldo , Selman Eliana 
Published: March 2007

AbstractHypospadias is one of the most prominent and characteristic midline defects in male infants with the Wolf‐Hirschhorn (4p —) syndrome. In this report we present a case in which hypospadias was identified prenatally at 29 weeks' gestation in association with intrauterine growth retardation. Cytogenetic evaluation after birth confirmed a 46, XY, del(4)(p14) karyotype. The prenatal identification of hypospadias in fetuses with intrauterine growth retardation and normal amniotic fluid should suggest a diagnosis of Wolf‐Hirschhorn syndrome.
Sonographic presentation of Hirschsprung's disease. A case of an entirely aganglionic colon and ileum
Authors: Eliyahu S. , Yanai N. , Blondheim O. , Reich D. , Siplovich L. , Shalev E. 
Published: March 2007

AbstractPrenatal sonographic presentation of Hirschsprung's disease has been considered non‐specific and uncommon. This report presents a second‐trimester fetus with an aganglionic colon and ileum diagnosed by the sonographic presentation of dilated fetal bowel loops, increased abdominal circumference, and mild polyhydramnios. The prenatal sonographic diagnosis of Hirschsprung's disease helped to expedite early neonatal treatment.
Prenatal aneuploidy detection in interphase cells by fluorescence in situ hybridization (Fish)
Authors: Philip J. , Bryndorf T. , Christensen B. 
Published: March 2007

AbstractFISH is a quick, inexpensive, accurate, sensitive and relatively specific method for aneuploidy detection in samples of uncultured chorionic villus cells and amniotic fluid cells. FISH allows detection of the autosomal trisomies 13, 18 and 21 and X and Y abnormalities and any other chromosome abnormality for which a specific probe is available. The detection rate of these abnormalities is high in informative samples which have a concordance of > 99.5% with cytogenetic results. A relatively high number of abnormal cases are found in uninformative samples. However, such samples should be regarded as samples to be investigated further. Clinical experience with the use of FISH for prenatal diagnosis is now beyond 10,000 cases; a number of clinical protocols and smaller trials have also been carried out, resulting in 90% of attempted analyses giving informative results with a high detection rate and extraordinarily low false‐positive and false‐negative rates Unsolved problems remain, such as occasional technical failures, admixtures of maternal blood and up to 20% uninformative scoring results, especially for abnormal specimens. FISH is at present used as an adjunct to classical cytogenetic analysis. However, this should not be interpreted as meaning that FISH could not be used as a methodology in its own right. If FISH were to be considered a Diagnostic test then this might be the case, due to the risk of false‐negative and false‐positive results and the fact that FISH does not allow a diagnosis of certain structural abnormalities. If, on the other hand, FISH is considered a screening test, which means that in all abnormal (or indeterminate) cases, classical cytogenetic analysis would follow the abnormal screening test, the accuracy which is potentially higher than for other screening methods, for example in cases of trisomy 21, justifies FISH as a prenatal screening test in its own right.
Preimplantation diagnosis
Authors: Delhanty J. D. A. 
Published: March 2007

AbstractResearch towards preimplantation diagnosis of genetic disease was initiated in the UK. in the mid 1980s with the aim of helping those couples who would prefer selection to occur at this stage rather than during pregnancy. Following in vitro fertilisation, (IVF), biopsy and removal of 1 or 2 of the totipotent cells from the cleavage stage 3 day old embryo provides the material for molecular genetic diagnosis without interfering with development. Earliest applications were in the avoidance of X‐linked disease by sexing embryos and selecting females for transfer to the mother. Initially, polymerase chain reaction (PCR) amplification of DNA from the biopsied blastomeres was performed using primers specific for sequences derived from the Y chromosome and this led to the birth of several normal girls. To reduce the risk of misdiagnosis due to amplification failure, PCR based methods for sexing the embryo now employ both X and Y specific sequences, but the preferred method is currently considered to be fluorescent in situ hybridisation (FISH) with fluorochrome labelled DNA probes to the embryonic nuclei that have been fixed and spread on slides. Dual FISH with probes from X and Y chromosomes allows unequivocal diagnosis of sex and determination of chromosome copy number, avoiding transfer of embryos with abnormal numbers of sex chromosomes, including those with only the maternal X that would be at 50% risk for the X‐linked disease. The application of FISH for preimplantation diagnosis has also led to the realisation that chromosomal mosaicism is common at the cleavage stage of development, a finding that has important implications for diagnosis of both dominant single gene disorders and trisomies, as well as for our understanding of early human development. Cloning and sequencing of the relevant genes has enabled the development of methods for the diagnosis of certain recessive single gene disorders in cleavage stage embryos. PCR based methods have to be developed for each condition, sometimes for each family if there is heterogeneity. Preimplantation diagnosis has been successful so far for cystic fibrosis, Tay Sachs disease, and Lesch‐Nyhan syndrome. Worldwide, 32 pregnancies have been established following all types of preimplantation diagnosis and with 29 babies born, there is no evidence for any adverse effect on development.
Carrier screening for cystic fibrosis
Authors: Brock D. J. H. 
Published: March 2007

AbstractA number of different models of CF carrier screening have now been tested in pilot trials. Apart from opportunistic and cascade testing (which are strictly speaking not true forms of screening), the major programmes have been directed either to young adults in primary care or to pregnant women in antenatal clinics. Only in the latter form of screening has sufficient data been collected to allow conclusions to be reached on the optimum mode of delivery. It seems very probable that when CF carrier screening passes into routine service, it will be the antenatal couple model that is used.
Prenatal diagnosis in Canada — 1990: A review
Authors: Stranc L. C. , Evans J. A. , Hamerton J. L. 
Published: March 2007

AbstractThis paper presents the results of a detailed study of the genetic prenatal diagnostic services available in Canada in 1990. All 22 genetic centres offering prenatal diagnostic services as well as the 64 laboratories processing samples were surveyed. Data were collected from each to determine what testing was being done, how many women were being tested, for what conditions, and with what outcomes. Also, data on the 35 formal outreach sites were collected. The statistics presented are for the 1990 calendar year. This survey was conducted for the Canadian Royal Commission on New Reproductive Technologies.
Maternal urinary β‐core fragment of hCG/creatinine ratios and fetal chromosomal abnormalities in the second trimester of pregnancy
Authors: Hayashi Meicho , Kozu Hiromu 
Published: March 2007

AbstractOur aim was to evaluate the potential value of the ratio of the maternal urinary beta‐core fragment of human chorionic gonadotropin (βC‐hCG) to creatinine (Cr) in discriminating between normal pregnancies and pregnancies associated with fetal chromosomal abnormalities. We hypothesized that pregnancies with fetal chromosomal abnormalities had abnormal quantities of βC‐hCG in the urine. The aims of the present study were to investigate retrospectively whether maternal urinary ratios of βC‐hCG/Cr are abnormal in women carrying fetuses with chromosome aberrations and to determine normative median values and a reference range for βC‐hCG/Cr between 14 and 19 weeks' gestation. Maternal urinary βC‐hCG and Cr concentrations were measured in 150 healthy women from 14 to 19 weeks and compared with ten cases of fetal chromosomal abnormalities matched for gestational age. The preliminary cut‐off points corresponded to 0·29 multiple of the normal median (MOM) and 2·83 MOM, which were equivalent to the tenth and 90th centiles of the normal range. Of ten cases of fetal chromosomal abnormalities, one out of one (100 per cent) case with trisomy 18 and three of four (75 per cent) cases of variant 9 chromosome had low βC‐hCG/Cr (≤0·29 MOM). One of five (20 per cent) cases with Down syndrome had elevated βC‐hCG/Cr (≤2·83 MOM). Urinary βC‐hCG/Cr ratios obtained in the second trimester may be useful for improved detection efficiency of Down syndrome, trisomy 18, and inversion of chromosome 9. Second‐trimester maternal urinary βC‐hCG/Cr should be investigated further as a potential marker for fetal chromosome anomalies.
Genetic amniocentesis in biamniotic twin pregnancies by a single transabdominal insertion of the needle
Authors: Buscaglia M. , Ghisoni L. , Bellotti M. , Marconi A. M. , Zamperini P. , Stripparo L. , Molinari A. , Grimoldi M. G. , Rossella F. 
Published: March 2007

AbstractWe present a technique to aspirate amniotic fluid from both sacs in biamniotic twin pregnancies using a single abdominal insertion with a spinal needle. It was successful in 48 out of 55 cases of biamniotic twin pregnancies referred to our perinatal unit between 1985 and 1994. The single insertion technique was used when the inter‐amniotic membrane was clearly evident and two separate free amniotic fluid pools could be reached by the operator with a single puncture. An adequate amount of amniotic fluid was sampled from both sacs to make a cytogenetic diagnosis in all cases. There were four fetuses with trisomy 21 in three twin pregnancies. In two cases, only one twin was affected whilst the co‐twin was normal, so that a selective feticide was performed. No miscarriages due to genetic amniocentesis were reported. After 1990, all genetic amniocenteses in biamniotic twin pregnancies (except for one case due to late booking) were performed between 14 and 15 weeks of gestation and with all cases except one, it was possible to sample both twins by a single puncture. We suggest that early amniocentesis (14–15 weeks) by a single abdominal puncture could be a reliable and safe alternative to first‐trimester chorionic villus sampling in twin pregnancies.
Prenatal ultrasound diagnosis of gastric outlet obstruction due to a pyloric web
Authors: Sharony Reuven , Sinow Robert , Asch Morris , Lachman Ralph 
Published: March 2007

AbstractGastrointestinal tract atresia has an incidence of 1 in 10 000 live‐births, while gastric outlet obstruction comprises only approximately 1 per cent of these malformations. A prenatally diagnosed case is described, followed by a discussion regarding the diagnosis and possible associated abnormalities.
Macroglossia: Prenatal ultrasonographic diagnosis and proposed management
Authors: Weissman Ariel , Mashiach Shlomo , Achiron Reuwen 
Published: March 2007

AbstractA case in which macroglossia was the sole unusual prenatal sonographic finding in a fetus affected with trisomy 21 is presented. The differential diagnosis of fetal macroglossia is given, emphasizing its strong relationship to fetal aneuploidy, together with the principles for evaluation and management.
Exencephaly in autosomal dominant brachydactyly syndrome
Authors: Stagiannis Konstantinos D. , Sepulveda Waldo , Fusi Luca , Garrett Christine , Fisk Nicholas M. 
Published: March 2007

AbstractExencephaly was diagnosed at 17 weeks in a 27‐year‐old primigravida with abnormalities of the hands and a family history suggestive of autosomal dominant brachydactyly and clinodactyly. In this family there was also a history of ‘anencephaly’. To our knowledge, this is the first report on the association of exencephaly and autosomal dominant brachydactyly. As the relationship between hand and cranial anomalies is well established, we suggest that this association in our case could be due to a defect in the same gene.
Development of non‐invasive fetal DNA diagnosis from maternal blood
Authors: Takabayashi Haruo , Kuwabara Soryu , Ukita Toshihiko , Ikawa Kazumi , Yamafuji Kaoru , Igaras Tatsuhiro 
Published: March 2007

AbstractSeveral attempts have been made to detect and retrieve fetal nucleated cells including nucleated erythrocytes (NRBCs), leukocytes, and trophoblasts in maternal blood. We have recently developed a new method for non‐invasive fetal DNA diagnosis from maternal blood. Peripheral blood granulocytes including NRBCs were isolated by a discontinuous density gradient method using Percoll (Pharmasia). NRBCs were found and retrieved at a single cell level using a micromanipulator under a microscope. To determine whether the origin of the NRBCs was maternal or fetal, the NRBCs were analysed by polymerase chain reaction (PCR) amplification to determine the presence of a Y‐chromosome‐specific repeat sequence in mothers carrying male fetuses. We were successful in predicting fetal sex accurately in 10 out of 11 samples taken from maternal blood. This new technique opens up fetal DNA diagnosis from maternal blood during the first trimester of pregnancy to the whole population because there is no risk to the fetus or the mother.
Mid‐trimester fetal sex determination from maternal peripheral blood by fluorescence in situ hybridization without enrichment of fetal cells
Authors: Hamada Hiromi , Arinami Tadao , Sohda Satoshi , Hamaguchi Hideo , Kubo Takeshi 
Published: March 2007

AbstractTo determine the fetal sex on 30 women who were 16–20 weeks pregnant, about 100 000 maternal blood nucleated cells were analysed by means of fluorescence in situ hybridization (FISH) with a Y‐chromosome‐specific DNA probe. Cells with the hybridization signal were detected in 12 of the 30 women. All the 12 mothers gave birth to a male child. Of the other 18 women who had no Y‐positive cells in the peripheral blood, 14 gave birth to a female child and four gave birth to a male child. These false‐negative results probably occurred because the number of cells examined was inadequate. The data obtained in this study suggest that fetal sex determination using maternal peripheral blood with FISH is possible and that this diagnostic method will be clinically useful when more cells are analysed.
An audit of trisomy 16 in man
Authors: Wolstenholme J. 
Published: March 2007

AbstractSufficient information is now available from the literature to produce an audit of trisomy 16, in a theoretical cohort of 100 000 recognized pregnancies, from gametogenesis to term and onwards. Recent reports of premature separation of chromosome 16 bivalents during maternal meiosis I provide a novel mechanism for generation of this aneuploidy. Most, if not all, errors resulting in recognized mosaic and non‐mosaic trisomy 16 pregnancies investigated using polymorphic DNA markers appear to originate at that stage. The incidence of this maternally derived trisomy 16 in the late first trimester is equivalent to 1500 cases in 100 000 recognized pregnancies, a figure which now corresponds very closely to the reinterpreted oogenesis data. Most trisomy 16 pregnancies are lost around 12 weeks' gestation, but of the order of 10 per cent (120–150 in this audit) undergo reduction to disomy, with 30 of these excluding aneuploidy from the fetal cell lineage (trisomic zygote rescue) and continuing into the second trimester. Maternal uniparental disomy (UPD) in one‐third of this latter group is associated with loss later in pregnancy or severe intrauterine growth retardation, but can be compatible with a viable pregnancy. Adverse pregnancy outcomes are not restricted to those with UPD. Analysis of reports of confined placental mosaicism for chromosome 16 without associated UPD indicates that the presence of high levels of trisomic cells in the placenta alone consistently produces a more variable inhibition of fetal growth, which may also, in cases, be associated with late pregnancy loss.
Prenatal diagnosis of neurofibromatosis type 1: From flanking rflps to intragenic microsatellite markers
Authors: Lazaro Conxi , Gaona Antonia , Ravella Anna , Volpini Victor , Estivill Xavier 
Published: March 2007

AbstractEven though the neurofibromatosis type 1 (NF1) gene was cloned more than 3 years ago, the process of identifying mutations has not been fruitful, and genetic counselling is mainly based on the use of linked markers. Since 1990, we have analysed 130 NF1 families and have performed six prenatal diagnoses. In each case, genetic counselling has relied on linked markers and informativity was achieved in all of them. The use of intragenic microsatellite polymorphisms (IVS27AAAT2.1, IVS27AC28.4, IVS27AC33.1, and IVS38GT53.0) has increased the informativeness in our series of NF1 families to an average of 90 per cent, providing accurate diagnosis and confirmation of the disease status.
Rapid fetal karyotype from cystic hygroma and pleural effusions
Authors: Costa D. , Borrell A. , Margarit E. , Carrió A. , Soler A. , Balmes I. , Estivill X. , Fortuny A. 
Published: March 2007

AbstractFluid from pleural effusion (n=2) and cystic hygroma (n=7) was obtained from eight fetuses, between 13 and 32 weeks of pregnancy at the time when a conventional prenatal diagnosis procedure was carried out. As these fluids contain lymphocytes, they were processed like peripheral blood. A karyotype was obtained in 4 days in both cases of pleural effusion and in four out of seven samples of cystic hygroma. An abnormal karyotype was detected in three of the four samples of cystic hygroma: two trisomies 21 and a monosomy X. Different parameters were evaluated in order to predict the feasibility of obtaining a cytogenetic diagnosis. Our data showed that if the amount of fluid obtained was ⩾4 ml and the initial lymphocyte count (ILC) was >0.2 × 106 cells/ml, a cytogenetic diagnosis was possible from an initial concentration of cultured lymphocytes )ICCL) of >0.06 × 106 cells/ml.
Oligohydramnios with amnio‐chorionic separation at 15–16 weeks' gestation
Authors: Bronshtein Moshe , Zimmer Etan Z. 
Published: March 2007

AbstractNine patients with oligohydramnios and amnio‐chorionic separation were identified out of 7000 women who underwent a vaginal ultrasound examination at 15–16 weeks' gestation. Oligohydramnios was defined as a reduced amount of amniotic fluid, a distance of more than 1 cm between the chorion and amnion, and a good turgor of the amnion without floating membranes or intrauterine sheets. Fetal malformations were observed in all nine cases. In four of six fetuses where chromosomal analysis was available, an abnormal karyotype was found. It is concluded that oligohydramnios in the early second trimester is associated with fetal abnormality.
Early second‐trimester diagnosis of sirenomelia
Authors: Van Zalen‐Sprock M. M. , Van Vugt J. M. G. , Van Der Harten J. J. , Van Geijn H. P. 
Published: March 2007

AbstractTwo cases of sirenomelia are described, detected in the 14th and 16th weeks of gestation by transvaginal ultrasonography. A hypothesis for the aetiology of sirenomelia and its associated anomalies is discussed.