1/14. A trisomic germ cell line and precocious chromatid segregation leads to recurrent trisomy 21 conception.A chromosomally normal 37-year-old woman was referred for preimplantation genetic diagnosis after having several conceptuses with trisomy 21. Segregation of chromosome 21 was assessed in unfertilised meiosis II oocytes and preimplantation embryos from PGD cycles using fluorescent in situ hybridisation (FISH). Of 7 preimplantation embryos, 5 were chromosomally abnormal with 4 having trisomy 21 and one being tetraploid. Of 4 oocytes, 3 had an abnormal chromosomal constitution with either an extra chromosome 21 or an extra chromatid 21. In one oocyte an extra chromatid 21 was detected in both the metaphase II complement and the first polar body providing the first direct evidence of a maternal trisomic germ cell line. Moreover, this result shows that the extra chromosome 21 can precociously divide into its two chromatids at the first meiotic division.- - - - - - - - - - ranking = 1keywords = preimplantation, embryo (Clic here for more details about this article) |
2/14. trisomy/tetrasomy 21 mosaicism in CVS: interpretation of cytogenetic discrepancies between placental and fetal chromosome complements.trisomy/tetrasomy 21 mosaicism was found in chorionic villi (semidirect preparation) obtained from a 40 year old pregnant woman. Since both cell lines were abnormal, the couple elected for pregnancy termination. placenta and fetal tissue samples were obtained for cytogenetic study. Long term cultured villi showed a non-mosaic trisomy 21 karyotype, while other tissues showed either a normal karyotype or normal/trisomy21 mosaicism. These discrepancies could be explained by a modified "bottle neck" embryogenic model with a trisomic zygote and a non-disjunction event taking place in one of the first divisions. Our case emphasises the need for confirmatory studies in other tissues when mosaicism is encountered in chorionic villi, even if all cell lines are abnormal.- - - - - - - - - - ranking = 0.0046780269497571keywords = embryo (Clic here for more details about this article) |
3/14. Successful pregnancy and delivery from frozen-thawed embryos after intracytoplasmic sperm injection using round-headed spermatozoa and assisted oocyte activation in a globozoospermic patient with mosaic down syndrome.OBJECTIVE: To describe a successful pregnancy and delivery from frozen-thawed embryos after intracytoplasmic sperm injection (ICSI) and assisted oocyte activation in a globozoospermic patient with mosaic down syndrome. DESIGN: Controlled clinical study. SETTING: IVF Laboratory, PL infertility Clinic, Seoul, korea. PATIENT(S): A couple with infertility resulting from globozoospermia with mosaic down syndrome: 47,XY, 21[7]/46,XY[33]. INTERVENTION(S): semen analysis, karyotyping, ICSI, assisted oocyte activation, assisted hatching, and frozen-thawed ET. MAIN OUTCOME MEASURE(S): fertilization rate, implantation, pregnancy, and delivery. RESULT(S): Thirty-eight oocytes were aspirated, and round-headed spermatozoa were injected into 35 oocytes in metaphase II. Assisted oocyte activation with calcium ionophore A23187 after ICSI resulted in a high fertilization rate (21 of 35, 60%; 2 pronuclei in 18 of 21; 3 pronuclei in 3 of 21) and good embryo development. At 3 days after ICSI, 5 embryos of good quality were surgically transferred to the endometrium after assisted hatching, but no pregnancy occurred. After 2 months, the surgical transfer of 4 frozen-thawed embryos after assisted hatching led to an ongoing pregnancy. A female infant weighing 3,000 g was delivered at 38 weeks of gestation by cesarean section. CONCLUSION(S): We report the first successful pregnancy and delivery from frozen-thawed embryos after ICSI and assisted oocyte activation in a globozoospermic patient with mosaic down syndrome.- - - - - - - - - - ranking = 0.042102242547814keywords = embryo (Clic here for more details about this article) |
4/14. Aspects of intracranial and spinal tumors in patients with down syndrome and report of a rapidly progressing Grade 2 astrocytoma.BACKGROUND: Brain tumors in patients with down syndrome (DS) rarely are reported, and their behavior is not well known. methods: The authors report on a male patient age 19 years who had DS with diffuse astrocytoma (world health organization Grade 2) that recurred twice despite treatment, leading to a glioblastoma and, finally, to death in just over 2 years. The literature on brain tumors in patients with DS is reviewed. RESULTS: Although brain neoplasms were suspected to be in excess in patients with DS, the authors found only 36 patients with brain neoplasms and 2 spinal tumors. An unusual distribution of histologic tumor types, with an over-representation of germ cell and mesenchymal tumors and a lack of embryonal tumors, was observed, in agreement with what is known currently about the tumor profile of patients with DS. CONCLUSIONS: Cerebral tumors in patients with DS have a specific distribution and may behave differently compared with the general population. These features may be related to the gene dosage effect of oncogenes, antioncogenes, and genes involved in cerebral development due to the supernumerary chromosome 21.- - - - - - - - - - ranking = 0.0046780269497571keywords = embryo (Clic here for more details about this article) |
5/14. Robertsonian translocations--reproductive risks and indications for preimplantation genetic diagnosis.BACKGROUND: Robertsonian translocations carry reproductive risks that are dependent on the chromosomes involved and the sex of the carrier. We describe five couples that presented for preimplantation genetic diagnosis (PGD). methods: PGD was carried out using cleavage-stage (day 3) embryo biopsy, fluorescence in-situ hybridization (FISH) with locus-specific probes, and day 4 embryo transfer. RESULTS: Couple A (45,XX,der(14;21)(q10;q10)) had two previous pregnancies, one with translocation trisomy 21. A successful singleton pregnancy followed two cycles of PGD. Couple B (45,XX,der(13;14)(q10;q10)) had four miscarriages, two with translocation trisomy 14. One cycle of PGD resulted in triplets. Couple C (45,XX,der(13;14)(q10;q10)) had four years of infertility; two cycles were unsuccessful. Couple D (45,XY,der(13;14)(q10;q10)) presented with oligozoospermia. A singleton pregnancy followed two cycles of PGD. Couple E (45,XY,der(13;14)(q10;q10)) had a sperm count within the normal range and low levels of aneuploid spermatozoa. PGD was therefore not recommended. No evidence for a high incidence of embryos with chaotic or mosaic chromosome complements was found. CONCLUSIONS: For fertile couples, careful risk assessment and genetic counselling should precede consideration for PGD. Where translocation couples need assisted conception for subfertility, PGD is a valuable screen for imbalance, even when the risk of viable chromosome abnormality is low.- - - - - - - - - - ranking = 1.6651073243501keywords = preimplantation, embryo (Clic here for more details about this article) |
6/14. Intramural esophageal hamartoma. An unusual cause of progressive stricture in a child.The unusual occurrence of an intramural hamartoma mimicking a peptic esophageal stricture in a child is presented. Early operative intervention is indicated to diagnose the condition and to avoid certain morbidity or death. The remarkable embryologic feature of this report is the presence of annular cartilage at the site of the esophageal stricture. Conservative resection of the involved esophagus and primary anastomosis is the treatment of choice.- - - - - - - - - - ranking = 0.0046780269497571keywords = embryo (Clic here for more details about this article) |
7/14. A chromosome 21-derived minute marker in a mosaic trisomy 21 background: implications for risk assessments in marker chromosome cases.We report a prenatal case of a chromosome 21-derived minute supernumerary marker, found as a mosaic along with a trisomy 21 cell line at amniocentesis. Follow-up analysis of other fetal tissues confirmed the mosaicism and also disclosed a normal cell line. It is likely that the marker reflects a mutation event that resulted in trisomy rescue early in embryonic development. Had the trisomy 21 cell line not been found at amniocentesis, a low risk of an abnormal phenotype (approximately 5%) would have been assigned. We suggest that the risk associated with minute non-euchromatic marker chromosomes should be revised to account for the possibility of mosaicism with potentially aneuploid populations and/or uniparental disomy (UPD). The finding of any marker chromosome should prompt a thorough investigation for aneuploid cell lines. In the case of small markers with no euchromatin, the given risk of adverse phenotypic effects is not likely to be associated with the marker per se but with the possible presence of a cryptic aneuploid cell line from which the marker may have arisen.- - - - - - - - - - ranking = 0.0046780269497571keywords = embryo (Clic here for more details about this article) |
8/14. trisomy 21 with 47, 18 lymphocyte cell line: double mitotic nondisjunction.A patient with Down's syndrome was found to have 47,XX, 18/47,XX, 21 mosaicism. Chromosome 18 trisomy was found only in 18% of lymphocytes and not in skin fibroblasts. A likely interpretation is double nondisjunction in a single lymphocyte precursor of a trisomy 21 embryo. A brief review of other cases of mitotic multiple nondisjunction and double aneuploid mosiacism is presented.- - - - - - - - - - ranking = 0.0046780269497571keywords = embryo (Clic here for more details about this article) |
9/14. Abnormal embryonic heart rate pattern in early pregnancy associated with Down's syndrome.The case history of a 35-year-old woman with a pregnancy following IVF treatment is presented. Transvaginal sonography revealed an abnormal pattern of the embryonic heart rate between 28 and 50 days following follicular aspiration. At term, a male infant with the characteristics of Down's syndrome was born. The diagnosis was confirmed by chromosome analysis. The implications of this observation are discussed.- - - - - - - - - - ranking = 0.023390134748785keywords = embryo (Clic here for more details about this article) |
10/14. Translocation trisomy 21 in CVS not found in embryoblast: three different cell lines in CVS, amnion- and placental culture.Chorionic villus samples from a healthy pregnant female were obtained for first-trimester prenatal diagnosis. A translocation trisomy 21 was diagnosed. A consecutive amniocentesis revealed a normal male karyotype. At term a healthy boy was born. cytogenetic analysis from cord blood showed a regular karyotype of 46,XY, whereas in term placenta a pathological karyotype of 47,XY, mar was found.- - - - - - - - - - ranking = 0.018712107799028keywords = embryo (Clic here for more details about this article) |
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