Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Trisomy 9 Mosaicism Diagnosed In Utero  [PDF]
Hironori Takahashi,Satoshi Hayashi,Yumiko Miura,Keiko Tsukamoto,Rika Kosaki,Yushi Itoh,Haruhiko Sago
Obstetrics and Gynecology International , 2010, DOI: 10.1155/2010/379534
Abstract: We present three cases of trisomy 9 mosaicism diagnosed by amniocentesis with ongoing pregnancies after referral to our center due to fetal abnormalities. Two cases were associated with severe fetal growth restriction (FGR), each of which resulted in an intrauterine fetal demise (IUFD) in the third trimester. The other case involved mild FGR with a congenital diaphragmatic hernia and resulted in a live birth with severe development delay. A major prenatal finding of trisomy 9 mosaicism is FGR. Fetuses with trisomy 9 mosaicism can rarely survive in the case of severe FGR. 1. Introduction Trisomy 9 mosaicism is a rare chromosomal abnormality that manifests with multiple anomalies, such as facial, cardiac, osteal, genitourinary, and respiratory abnormalities. More than 50 cases have been reported, most of which were diagnosed after birth. As cases diagnosed prenatally usually culminate in induced abortions [1–4], the natural history of fetuses with trisomy 9 mosaicism remains unknown. We report three cases of trisomy 9 mosaicism diagnosed in utero with ongoing pregnancies. 2. Case Report A 36-year-old primigravida was referred to our institute at 29 weeks of gestation because of fetal growth restriction (FGR). A fetal ultrasound examination demonstrated severe asymmetric FGR ( ?3.0 standard deviation [SD]) and a single umbilical artery (SUA). An amniocentesis revealed that 27 were normal 46, XX cells and 3 cells (10%) were 47, XX, +9. An intrauterine fetal demise (IUFD) was confirmed at 33 weeks of gestation. The fetus was a 915?g female with a large forehead, a bulbous nose, and micrognathia. The placental weight was 150?g. An autopsy revealed an abnormal lobulation of the right lung. The second case was that of a 36-year-old primigravida. She was referred to our institute at 31 weeks of gestation due to a left-sided congenital diaphragmatic hernia. The estimated fetal body weight by ultrasound was 1408?g (?1.7 SD). The fetal karyotype by amniocentesis indicated trisomy 9 mosaicism with 29% (6/21 cells) trisomic cells. At 37 weeks of gestation, a 1506?g male was delivered by elective cesarean section. The placenta weighed 350?g. The diaphragmatic hernia was repaired on day 2 of life, followed by a gastrostomy and bronchotomy in the 1st year. Although he had normal G-banding results on postnatal blood karyotyping, interphase FISH performed on abdominal wall muscle tissue obtained during the gastrostomy revealed a mosaic trisomy 9 karyotype. This case has been reported to highlight the cytogenetic discrepancy between amniocytes and postnatal blood [5]. He
Meiotic errors followed by two parallel postzygotic trisomy rescue events are a frequent cause of constitutional segmental mosaicism
Caroline Robberecht, Thierry Voet, Gülen E Utine, Albert Schinzel, Nicole de Leeuw, Jean-Pierre Fryns, Joris Vermeesch
Molecular Cytogenetics , 2012, DOI: 10.1186/1755-8166-5-19
Abstract: For decades, knowledge about copy number variation (CNV) in the human genome was limited to microscopically visible changes. Advances in technology have led to the discovery of submicroscopic CNVs, ranging from kilobases to megabases in size and covering up to 13% of the human genome [1,2]. These CNVs can cause recurrent genomic disorders and sporadic disease, or they can represent benign changes found in the healthy population [3,4]. Recent studies have revealed that CNVs are not only polymorphic between unrelated individuals, but also form a frequent source of somatic variation [5,6].Chromosomal mosaicism is defined as the coexistence of two or more chromosomally different cell lines in an organism which developed from a single zygote. The majority of those mosaicisms are aneuploidies. Several studies investigating in vitro fertilized embryos at the preimplantation stage demonstrated a very high number of chromosomal mosaicisms in early human embryos [7-9]. While many of these embryos will not reach the stage of implantation, some do continue to develop leading to fetal mosaicisms, confined placental mosaicism or mosaic infants. Postnatally, mosaicism is detected in 0.4-1% of patients referred for genetic diagnostic screening [10-12]. A recent study revealed that mosaic aberrations are present in about 0.8% of phenotypically normal adults [13]. In addition, mosaicism appears to be variable amongst different tissues: chromosomal aneuploidies were detected in approximately 10% of normal human brain cells [14].Segmental aneuploidies make up a significant part of mosaic chromosome anomalies. Analysis of several large series of prenatal samples by karyotyping has shown that, of the 0.25-2% mosaic cases that are detected, up to a third comprise segmental imbalances [15,16]. In postnatal clinical diagnosis of patients with developmental anomalies this increases to about half of the mosaic cases [10,17]. The majority of mosaic segmental imbalances are marker chromosomes [
Chromosomal mosaicism goes global
Ivan Y Iourov, Svetlana G Vorsanova, Yuri B Yurov
Molecular Cytogenetics , 2008, DOI: 10.1186/1755-8166-1-26
Abstract: Chromosomal mosaicism was originally defined as the presence of cells differing with respect to their chromosome complement in the same individual [1]. Although chromosomal mosaicism is repeatedly registered during cytogenetic analysis, one of the commonest genetic tests in medical genetics [2], its significance remains usually underappreciated. Nonetheless, during the last decade, a growing amount of studies has demonstrated that chromosomal mosaicism does contribute to human diversity [3-7], diseases [2,4,5,7-12], early prenatal brain development [3,13], and aging [14]. However, the real biomedical meaning of chromosomal mosaicism in humans is hardly known.One of the previous studies published in Molecular Cytogenetics [15] has brought evidences that chromosomal mosaicism plays a role in the generation of meiotic aneuploidy known to be the leading genetic cause of human prenatal death and congenital malformations/learning disabilities [4,5,16]. Studying chromosome 21 in ovarian cells of normal female foetuses, Prof. Maj Hulten and her colleagues were able to give experimental support for their original hypothesis suggesting meiotic aneuploidy in human conceptuses to be the result of ovarian germline mosaicism that is produced during the normal prenatal development [15]. The data fit well with current concepts in biology of aneuploidy, essentially drawn from studies of trisomy 21 (Down's syndrome) [16]. More specifically, these findings have the potential to explain maternal age effect, recurrence of aneuploidy at subsequent conceptions, and abnormal maternal recombination patterns previously found via linkage analyses [15]. Although the idea put forward in this article has revolutionized our thinking about maternal meiotic aneuploidy suggesting mitotic aneuploidy to lie at the origin of meiotic aneuploidy, there was a strong experimental background for this hypothesis. Firstly, it has been recently noticed that chromosomal mosaicism is frequent among human foetuse
The correlation fish karyotyping in prenatal diagnosis  [cached]
Ruxandra Cretu,Daniela Neagos,Andreea Musteata,Bohiltea Roxana
Analele ?tiin?ifice Ale Universit??ii Alexandru Ioan Cuza din Ia?i,Sectiunea II A : Genetica si Biologie Moleculara , 2010,
Abstract: Antenatal detection the chromosome abnormalities in high risk pregnancies and correlation between karyotype analysis and FISH (Fluorescent In Situ Hybridization). Amniotic fluid karyotyping and FISH have been offered to pregnant women with genetic risk, using the standard method and GTG banding techniques. Were found 22 abnormal karyotypes: 13 cases with numerical abnormalities (13 homogenuous aneuploidies: trisomies – 3 cases of 47,XX+21, 3 cases of 47,XY+21; 2 cases of 47,XY+18, 1 case of 47,XXY, 2 cases of 47,XXX and monosomies – 1 case of 45,X0; 1 triploidy - 69 XXX), 1 structural abnormality, one case of 46, XY, der(14;21)(q10;q10) +21) and 8 normal variants (3 cases of 46, XX inv(9)(p11;q13); 1 case with 46,XY inv (3)(p11;q11.2); 2 cases with 46,XX inv(3)(p11; q11.2), 1 case 46,XY inv(3)(p11; q11.2), and 1 case of 46,XY inv (3)(p11;q11.2) inv(9)(p11;q13)). This report confirms the importance of karyotyping and FISH in prenatal diagnosis, FISH being much more important for prenatal diagnosis due to the short time of results.
Spectral Karyotyping for identification of constitutional chromosomal abnormalities at a national reference laboratory
Arturo Anguiano, Boris T Wang, Shirong R Wang, Fatih Z Boyar, Loretta W Mahon, Mohamed M El Naggar, Peter H Kohn, Mary H Haddadin, Vladimira Sulcova, Adam H Sbeiti, Mervat S Ayad, Beverly J White, Charles M Strom
Molecular Cytogenetics , 2012, DOI: 10.1186/1755-8166-5-3
Abstract: Spectral karyotyping is an invaluable diagnostic tool in constitutional studies for identifying marker chromosomes and chromosomal exchanges that are not fully defined by conventional cytogenetic methods [1,2]. This is especially true in cases involving de novo small supernumerary marker chromosomes (sSMCs) and derivative chromosomes [3-6]. Such definitive karyotyping is important in assessing risk for phenotypic abnormalities, especially for prenatal situations [7,8]. The ability to identify the origin of additional genetic materials is very important for providing information to couples in regard to the potential phenotypic and/or developmental effect of a de novo rearrangement. Similarly, in evaluation of infertility, the identification of derivative chromosomal material may shed light on the mechanism of infertility [9,10].Although spectral karyotyping was developed more than a decade ago, few large-scale studies have assessed its ability to further resolve constitutional chromosomal rearrangements initially identified with conventional GTG-banding (G-banding) cytogenetic analysis. The primary aim of this study was to assess the utilization of spectral karyotyping for resolving chromosome abnormalities that are not well delineated by conventional G-banding.We reviewed the results of spectral karyotyping and confirmatory FISH testing performed on 179 consecutive clinical specimens (31 prenatal and 148 postnatal specimens) submitted to our national reference laboratory. In both prenatal and postnatal settings, the most common indication for spectral karyotyping analysis was the presence of chromosomal material not defined by conventional G-banding. Chromosomal abnormalities included unidentified marker chromosomes, additional rearranged material of unknown origin, ring chromosomes, and various complex rearrangements.The spectral karyotyping assay protocol recommended by the vendor (Applied Spectral Imaging, Carlsbad, CA) was followed. Emphasis was placed on the ex
Noninvasive Prenatal Molecular Karyotyping from Maternal Plasma  [PDF]
Stephanie C. Y. Yu, Peiyong Jiang, Kwong W. Choy, Kwan Chee Allen Chan, Hye-Sung Won, Wing C. Leung, Elizabeth T. Lau, Mary H. Y. Tang, Tak Y. Leung, Yuk Ming Dennis Lo, Rossa W. K. Chiu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0060968
Abstract: Fetal DNA is present in the plasma of pregnant women. Massively parallel sequencing of maternal plasma DNA has been used to detect fetal trisomies 21, 18, 13 and selected sex chromosomal aneuploidies noninvasively. Case reports describing the detection of fetal microdeletions from maternal plasma using massively parallel sequencing have been reported. However, these previous reports were either polymorphism-dependent or used statistical analyses which were confined to one or a small number of selected parts of the genome. In this report, we reported a procedure for performing noninvasive prenatal karyotyping at 3 Mb resolution across the whole genome through the massively parallel sequencing of maternal plasma DNA. This method has been used to analyze the plasma obtained from 6 cases. In three cases, fetal microdeletions have been detected successfully from maternal plasma. In two cases, fetal microduplications have been detected successfully from maternal plasma. In the remaining case, the plasma DNA sequencing result was consistent with the pregnant mother being a carrier of a microduplication. Simulation analyses were performed for determining the number of plasma DNA molecules that would need to be sequenced and aligned for enhancing the diagnostic resolution of noninvasive prenatal karyotyping to 2 Mb and 1 Mb. In conclusion, noninvasive prenatal molecular karyotyping from maternal plasma by massively parallel sequencing is feasible and would enhance the diagnostic spectrum of noninvasive prenatal testing.
Interactive Karyotyping Training
Ashwin Kotwaliwale
Journal of Krishna Institute of Medical Sciences University , 2013,
Abstract: Despite the wide use of newer techniques in genetic diagnostics, there remains a need for technologists to learn human chromosome morphology, identify abnormal metaphases and report clinical abnormalities. Global short age of cytogenetic trainers and a time consuming training process makes Karyotyping training difficult. We have developed a web based interactive Karyotyping training tool, KaryoTutor , that allows technologists to learn karyotyping in an interactive environment and aids the trainer in the training process. KaryoTutor provides visual clues for identifying abnormal chromosomes, provides instant test scores and includes a reference library of ideograms,sample chromosome images and reference materials. Trainees are able to recursively work on a case till a satisfactory result is achieved,with KaryoTutor providing interactive inputs.Additionally, trainers can assign cases and monitor trainee progress using audit trail management and other administrative features.
Array-based comparative genomic hybridization is more informative than conventional karyotyping and fluorescence in situ hybridization in the analysis of first-trimester spontaneous abortion
Jinsong Gao, Congcong Liu, Fengxia Yao, Na Hao, Jing Zhou, Qian Zhou, Liang Zhang, Xinyan Liu, Xuming Bian, Juntao Liu
Molecular Cytogenetics , 2012, DOI: 10.1186/1755-8166-5-33
Abstract: Abnormalities were detected in 61 cases. aCGH achieved the highest detection rate (93.4%, 57/61) compared with traditional karyotyping (77%, 47/61) and FISH analysis (68.9%, 42/61). aCGH identified all chromosome abnormalities reported by traditional karyotyping and interphase FISH analysis, with the exception of four triploids. It also detected three additional aneuploidy cases in 37 specimens with ‘normal’ karyotypes, one mosaicism and 10 abnormalities in 14 specimens that failed to grow in vitro.aCGH analysis circumvents many limitations in traditional karyotyping or FISH. The accuracy and efficiency of aCGH in spontaneous abortions highlights its clinical usefulness for the future. As aborted tissues have the potential to be contaminated with maternal cells, the threshold value of detection in aCGH should be lowered to avoid false negatives.
Is routine karyotyping required in prenatal samples with a molecular or metabolic referral?
Angelique JA Kooper, Jacqueline JPM Pieters, Brigitte HW Faas, Lies H Hoefsloot, Ineke van der Burgt, Hans A Zondervan, Arie PT Smits
Molecular Cytogenetics , 2012, DOI: 10.1186/1755-8166-5-7
Abstract: Currently, there is no evidence available in the literature indicating that the prevalence of chromosomal abnormalities is higher in pregnancies with a referral for DNA mutation or metabolic testing. Although the European cytogenetic guidelines for prenatal diagnosis [1] indicate that both DNA mutation and metabolic testing do not serve as referral categories for traditional karyotyping (TK), most prenatal centres worldwide routinely offer TK as an additional test. In clinical practice, most couples referred for DNA mutation analysis also opt for TK [2].It can be disputed, however, whether TK is required when there is no a priori increased risk for chromosomal anomalies as compared to the normal population. On the other hand, it has been argued that when a risky invasive prenatal test is performed anyway, it is unethical not to concomitantly exclude the occurrence of putative chromosomal abnormalities [3]. With TK, a wide range of chromosomal abnormalities can be detected, including alterations in copy number (aneuploidy) and structural chromosomal rearrangements such as translocations and inversions, being either balanced or unbalanced. Targeted PCR-based assays such as multiplex ligation-dependent probe amplification (MLPA) or quantitative fluorescent PCR (QF-PCR), are highly suited for rapid aneuploidy detection (RAD) of the chromosomes 21, 18, 13, X and Y [4-12]. Previously, it has been suggested that if the referral reason is an increased risk of Down's syndrome, resulting from a positive screening test result or an advanced maternal age, karyotyping could effectively be replaced by RAD, provided that no structural fetal abnormality has been detected upon ultrasound examination [5,13-17]. The use of RAD as a targeted, standalone test instead of karyotyping when invasive prenatal testing is performed in cases with DNA mutation or metabolic test referrals, has not been studied before. This retrospective study addresses the clinical impact of TK for samples offere
Prenatal diagnosis of a trisomy 7/trisomy 13 mosaicism
Karin Huijsdens-van Amsterdam, Daniela QCM Barge-Schaapveld, Inge B Mathijssen, Mari?lle Alders, Eva Pajkrt, Alida C Knegt
Molecular Cytogenetics , 2012, DOI: 10.1186/1755-8166-5-8
Abstract: Double aneuploidy mosaicism of two different aneuploidy cell lines is a rare event [1]. The most frequently described combinations are a monosomy X cell line with a cell line containing a trisomy of an autosome. In literature, mosaicism of a monosomy X cell line with either a trisomy 7, 8, 10, 13, 18 or 21 have been reported [2-7]. Double autosomal trisomies are even more sporadic, and to date combinations of trisomies of the chromosomes 8 and 14, chromosomes 8 and 21, chromosomes 13 and 18, chromosomes 13 and 21, and chromosomes 18 and 21 have been reported [1,8-12].Here, we present the first report of a double trisomy mosaicism involving chromosomes 7 and 13 in both amniotic fluid and subsequent FISH analysis of fibroblasts in a fetus presenting with multiple congenital anomalies.A 17-year-old healthy woman of a non-consanguineous couple, gravida 1, para 0, was referred at 21+0 weeks' gestation because of multiple structural anomalies. There was no history of familial congenital anomalies or drug use. The pregnancy was unplanned but welcome. A dating scan had been performed at 8 weeks' gestation. A 12 weeks' scan was not performed since the parents did not wish screening for Down syndrome. The fetus showed growth restriction with a large bilateral cleft lip and palate with severe micrognathia. The caput showed mild brachycephaly, with an enlarged cisterna magna (> p95). The left little finger was bowed and there were mild clubfeet. Following genetic counselling the patient elected to have an amniocentesis for karyotyping. Moreover, the parents requested a termination of pregnancy.Labour was induced at 22+2 weeks and a female baby was born, who died shortly after birth. Her birth weight was 370 g. Autopsy confirmed the bilateral cleft lip and palate as well as the retrognathia, and revealed an internal malrotation of the digestive tract with the ileocecal valve situated in the upper abdomen on the left side and bicornate uterus. All body and organ measures were wit
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.