1/31. Maternal uniparental isodisomy for chromosome 14 detected prenatally.Maternal uniparental disomy (UPD) for chromosome 14 (upd(14)mat) has been associated with a distinct phenotype. We describe the first case of maternal uniparental isodisomy for chromosome 14 detected prenatally, in a pregnancy with mosaicism for trisomy 14 observed in both a chorionic villus sample (CVS) and in amniocytes. Detailed analysis of polymorphic microsatellites showed that the fetus was essentially isodisomic for one of the mother's chromosomes 14 and that recombination had introduced a mid-long arm region of heterodisomy. The fetus, which died in utero at 18 weeks, showed no apparent pathological features. The case demonstrates for the first time a maternal meiosis II non-disjunction of chromosome 14 leading to a trisomic conception which has been incompletely corrected by 'rescue' in the early embryo.- - - - - - - - - - ranking = 1keywords = conception (Clic here for more details about this article) |
2/31. Sperm chromosomal abnormalities are linked to sperm morphologic deformities.OBJECTIVE: To describe the association between specific sperm morphologic abnormalities and sperm chromosomal abnormalities on multicolor interphase fluorescence in situ hybridization (FISH). DESIGN: Case report.reproductive medicine unit in a tertiary referral center. PATIENT(S): Three infertile men with severe oligoasthenospermia and total teratozoospermia who were referred for IVF treatment. MAIN OUTCOME MEASURE(S): incidence of spermatozoal chromosomal aneuploidy for chromosome 18 and the sex chromosomes by using FISH. RESULT(S): Morphologic assessment of sperm revealed a high incidence of double heads, multinucleated sperm heads, and multiple tails. Hormone profiles and karyotyping of peripheral lymphocytes were normal in the three men. The proportion of sperm with disomy, trisomy and tetrasomy for chromosome 18, and the sex chromosomes in each patient was 100%, 76%, and 82.5%, respectively. CONCLUSION(S): Specific morphologic abnormalities of sperm may be associated with higher incidence of chromosomal abnormalities. Resolving infertility by offering patients in vitro fertilization/intracytoplasmic sperm injection must be approached with caution because of the significant risk for embryonic aneuploidy and chromosomal abnormalities in any subsequent offspring.- - - - - - - - - - ranking = 19.031673342774keywords = fertilization (Clic here for more details about this article) |
3/31. prenatal diagnosis of a karyotypically normal pregnancy in a mother with a supernumerary neocentric 13q21 -->13q22 chromosome and balancing reciprocal deletion.An adult female patient with a history of miscarriages was found to be carrying a stable supernumerary chromosome. The patient also carried a reciprocal paracentric deletion in chromosome 13q21/22. microdissection and reverse fluorescence in situ hybridization FISH revealed that this supernumerary chromosome was derived from region 13q21 --> 13q22. The presence of a neocentromere on this supernumerary chromosome was confirmed by the absence of detectable alpha satellite dna using FISH and the presence of centromere proteins CENP-C and CENP-A using immunofluorescence. The absence of telomere sequences suggests that the marker is a ring chromosome (r(13)). FISH using ordered BACs from the chromosome region 13q21 --> 13q31 permitted the precise positioning of the r(13) chromosome and the corresponding deletion to chromosome bands 13q21.32 --> 13q22.2. BAC 280J7 from within the r(13) was used as a FISH probe for the prenatal analysis of amniocytes at 16 weeks of gestation, which revealed a normal karyotype for the fetus. This r(13) chromosome represents the first description of chromosome 13 of the rarer class of neocentric chromosomes that are derived from interstitial deletions. It represents the first example of prenatal diagnosis in a phenotypically normal female that was ascertained to carry a neocentric marker. The presence of such a neocentric marker/deletion karyotype in a parent presents unique possible karyotypic outcomes for conceptions and unusual challenges for genetic counseling.- - - - - - - - - - ranking = 1keywords = conception (Clic here for more details about this article) |
4/31. trisomy 15 with loss of the paternal 15 as a cause of prader-willi syndrome due to maternal disomy.uniparental disomy has recently been recognized to cause human disorders, including prader-willi syndrome (PWS). We describe a particularly instructive case which raises important issues concerning the mechanisms producing uniparental disomy and whose evaluation provides evidence that trisomy may precede uniparental disomy in a fetus. Chorionic villus sampling performed for advanced maternal age revealed trisomy 15 in all direct and cultured cells, though the fetus appeared normal. Chromosome analysis of amniocytes obtained at 15 wk was normal in over 100 cells studied. The child was hypotonic at birth, and high-resolution banding failed to reveal the deletion of 15q11-13, a deletion which is found in 50%-70% of patients with PWS. Over time, typical features of PWS developed. Molecular genetic analysis using probes for chromosome 15 revealed maternal disomy. Maternal nondisjunction with fertilization of a disomic egg by a normal sperm, followed by loss of the paternal 15, is a likely cause of confined placental mosaicism and uniparental disomy in this case of PWS, and advanced maternal age may be a predisposing factor.- - - - - - - - - - ranking = 19.031673342774keywords = fertilization (Clic here for more details about this article) |
5/31. reproduction in a woman with low percentage t(21q21q) mosaicism.The birth of a child is described with down syndrome followed by the conception of a fetus bearing the t(21q21q) chromosome in 100% of their cells in a women mosiac for the translocation in less than 10% of 2 of her examined tissues and in none of the cells in her peripheral blood. Various hypotheses for explaining the above findings are discussed. The importance of examining as many parental tissues as possible for the detection of low percentage mosiacism is stressed.- - - - - - - - - - ranking = 1keywords = conception (Clic here for more details about this article) |
6/31. Preimplantation genetic diagnosis for a couple with recurrent pregnancy loss and triploidy.BACKGROUND: triploidy may arise from fertilization of a mature haploid egg by two haploid sperm or by failure of meiotic divisions yielding a diploid gamete. We encountered a couple with habitual abortion, in which the last two fetuses were documented as viable triploid. methods: To avoid dispermic penetration and development of abnormal preembryos, insemination was done by intracytoplasmic sperm injection (ICSI) followed by fluorescence in situ hybridization (FISH) of biopsied blastomeres. RESULTS: Tests of the husband's spermatozoa by FISH, revealed that only 2-3% of the sperm were disomic for chromosomes 16, 13, 21, X, and Y. No triple disomy was detected among chromosomes 16, 13 and 21, which makes it very unlikely that triploidy resulted from diploid spermatozoa. Following a controlled ovulation induction protocol, low quality oocytes with immature cumuli were revealed. After ICSI, five eggs became two pronuclei (2PN) zygotes and none of the other eggs developed a 3PN zygote. FISH was performed on chromosomes 16 and 21 in four preembryos developed to a 6-8 cell stage. aneuploidy or mosaicism for each of these chromosomes was detected in one preembryo and later in two disaggregated blastocysts. FISH failed in one preembryo that became atretic after biopsy. CONCLUSIONS: Although this case was unsuccessful in achieving embryo transfer and normal pregnancy, we detected many abnormal morphological features in the oocytes and chromosomal abnormalities in the cleaving preembryos. This protocol can be proposed to patients with recurrent pregnancy loss associated with chromosomal abnormalities in the fetus.- - - - - - - - - - ranking = 19.031673342774keywords = fertilization (Clic here for more details about this article) |
7/31. Preimplantation genetic diagnosis of human congenital heart malformation and Holt-Oram syndrome.Holt-Oram syndrome (HOS) is a multiple malformation syndrome associated with congenital heart malformation (CHM) and caused by mutations in the TBX5 transcription factor. Effective prenatal genetic diagnosis of HOS is limited by factors that modify clinical manifestations and confound prediction of an individual's phenotype. Although preimplantation genetic diagnosis (PGD) has been applied to complex disorders with some cardiovascular manifestations, its utility in Mendelian CHM has not been previously demonstrated. We tested whether PGD and in vitro fertilization (IVF) technology, including oocyte donation, can identify fertilized eggs affected by HOS for potential embryo selection. Five donor oocytes were fertilized in vitro with sperm from a HOS patient heterozygous for a Glu69ter-TBX5 mutation and then underwent embryo biopsy and genotyping. One carried the Glu69ter-TBX5 mutation; all others had wildtype genotypes. Two wildtype blastocysts were transferred to the mother, and the resulting singleton pregnancy was successfully delivered. Mutational analysis of fetal amniocytes and postpartum umbilical cord blood confirmed PGD. Fetal ultrasonography as well as postpartum electrocardiography and echocardiography also validated accurate prediction of normal skeletal and cardiac phenotypes. We conclude that PGD is an effective reproductive strategy for HOS patients. As more genetic etiologies for CHM are identified, application of PGD as adjunctive therapy to IVF will be increasingly available to prevent transmission of such diseases from affected parents to their children. Clinical application of PGD must balance the benefits of avoiding disease transmission with the medical risks and financial burdens of IVF.- - - - - - - - - - ranking = 19.031673342774keywords = fertilization (Clic here for more details about this article) |
8/31. A case of triploidy.OBJECTIVE: To report a case of triploidy in a women who conceived after intracytoplasmic sperm injection (ICSI). DESIGN: Case report. SETTING: Maternity unit of a university hospital. PATIENT(S): A 29-year-old woman who was pregnant following intracytoplasmic sperm injection (ICSI). INTERVENTION(S): Ultrasound and serum screening. MAIN OUTCOME MEASURE(S): amniocentesis and postmortem findings. RESULT(S): amniocentesis confirmed the karyotype to be 69XXY, and the pregnancy was terminated. CONCLUSION(S): This case refers to diandric triploidy resulting from fertilization by diploid sperm.- - - - - - - - - - ranking = 19.031673342774keywords = fertilization (Clic here for more details about this article) |
9/31. First trimester diagnosis of partial mole.BACKGROUND: Partial mole is one of the two distinctive subtypes of hydatidiform mole. It is usually paternally derived triploid conceptions in which embryonal development occurs in association with trophoblastic hyperplasia. The definite diagnosis is confirmed by pathological and cytogenetic studies. Ultrasound might be helpful to diagnose partial mole in the first trimester. CASE: A 25-year-old woman, gravida 2, para 0-0-1-0, was initially seen for antenatal care at 6 weeks' pregnant. Ultrasound was undertaken at 13 weeks' pregnancy due to her first fetal anomaly, which demonstrated partial mole and embryonic death. The serum beta hCG was 190,900 mIU/ml. suction curettage was performed without complication. Histopathological study confirmed partial mole and cytogenetic study of the placenta revealed an uncommon karyotype, mosaicism of triploid (69,XXX/69,XXY). serum beta hCG was declined and negative at 8 weeks. The patient was well and serum beta hCG remained normal throughout 6 months of follow-up. CONCLUSION: Although the majority of partial mole pregnancies cannot be detected by routine first trimester ultrasound examination, first trimester ultrasound can be helpful in some cases, such as this one. If partial mole is sonographically suspected, it should be confirmed with histopathology and cytogenetic studies. The management is similar to complete mole including prompt evacuation and careful monitoring of beta hCG.- - - - - - - - - - ranking = 1keywords = conception (Clic here for more details about this article) |
10/31. 69,XXX karyotype in a malformed liveborn female. Maternal origin of triploidy.A liveborn female with a 69,XXX karyotype and clinical features of triploidy syndrome is reported. Main phenotypical features are: intrauterine growth retardation, hypotonicity, micrognathism, low-set ears, ocular anomalies, syndactyly and atrophy of the cerebral cortex and corpus callosum. Study of chromosomal heteromorphisms revealed that triploidy might have arisen through fertilization of a diploid ovum by a haploid sperm (diginy).- - - - - - - - - - ranking = 19.031673342774keywords = fertilization (Clic here for more details about this article) |
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