1/9. Uniparental isodisomy resulting from 46,XX,i(1p),i(1q) in a woman with short stature, ptosis, micro/retrognathia, myopathy, deafness, and sterility.We report on a 43-year-old woman who was referred for evaluation because of minor facial anomalies, myopathy, sterility, short stature, hearing loss, downward slant of palpebral fissures, bilateral ptosis, severe micro/retrognathia, high arched palate, and scoliosis. Cytogenetic analyses utilizing GTG/CBG bandings showed presence of one i(1p) and one i(1q) without normal chromosome 1 homologues. fluorescence in situ hybridization analysis showed hybridization to only two chromosomes, consistent with the G-banded interpretation of i(1p) and i(1q). To the best of our knowledge, this is the first case of isochromosomes 1p and 1q replacing the two normal chromosome 1s. Molecular investigations using markers for chromosome 1 showed inheritance of only one set of paternal alleles and absence of any maternal alleles in the patient. The adverse phenotype of the patient may be due to one or more recessive mutations, genomic imprinting, or a combination of both.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/9. Analysis of the sex chromosome constitution of sperm in men with a 47, XYY mosaic karyotype by fluorescence in situ hybridization.OBJECTIVE: To determine the incidence of sex chromosome aneuploidy in the sperm of two men with a 47,XYY/46,XY karyotype. DESIGN: Case report. SETTING: infertility clinic in a teaching hospital. PATIENT(S): One patient with near normal semen parameters whose wife had a history of miscarriages and one patient with primary infertility and severe oligoasthenozoospermia. INTERVENTION(S): cytogenetic analysis of peripheral lymphocytes and three-color X/Y/18 fluorescence in situ hybridization analysis of sperm. MAIN OUTCOME MEASURE(S): Analysis of sex chromosome disomy and diploidy rates in sperm. RESULT(S): Both patients had a 47,XYY/46,XY karyotype. The hyperdiploidy rate of patient 1 was 19% and that of patient 2 was 90%. The incidence of disomy XY was significantly elevated in both patients compared with the controls (0.23% and 1.02%, respectively, versus 0.10%). The incidence of disomy YY (0.44% versus 0.10%) was increased only in patient 2, as was the incidence of disomy 18 (0.49% versus 0.09%) and the rate of diploidy (0.83% versus 0.13%). The rate of 24,XX sperm in both patients was not different from that in the controls. CONCLUSION(S): patients with a 47,XYY mosaic karyotype may be at risk of producing offspring with a hyperdiploid sex constitution. These patients should have their sperm investigated by fluorescence in situ hybridization to determine their particular risks before they undergo intracytoplasmic sperm injection.- - - - - - - - - - ranking = 3keywords = hybridization (Clic here for more details about this article) |
3/9. A balanced complex chromosomal rearrangement (BCCR) in a family with reproductive failure.Balanced complex chromosomal rearrangements are very rare events in the human population. Translocations involving three or more chromosomes frequently lead to a severe reproductive impairment secondary to meiotic disturbance in males and to chromosomal imbalance in gametes of females. We report a new familial case of complex chromosome anomaly involving chromosomes 13, 14 and 22. Cytogenetic investigations showed a complex chromosomal chromosome rearrangement involving: (i) a Robertsonian translocation between chromosomes 13 and 14; and (ii) a reciprocal translocation between the long arms of chromosome 14 and the long arm of chromosome 22. The aetiology of the translocation was characterized by conventional fluorescence in-situ hybridization (FISH) studies and routine R- and G-banding (RTBG and GBTG) combined with alpha and beta satellite centromeric FISH probes. Predicted configuration of the hexavalent at pachytene stage of meiosis was used to consider the modes of segregation; only two configurations resulted in a normal or balanced gamete karyotype. Reproductive management and genetic counselling are discussed.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
4/9. infertility and marker chromosomes: application of molecular cytogenetic techniques in a case of inv dup(15).We report on a phenotypically normal man with infertility, whose 47,XY, mar karyotype was studied by spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) using a chromosome-15-specific probe (LSI SNRPN). By these techniques, the marker chromosome was identified as a small inv dup (15). Possible causes for male infertility in this case are discussed.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
5/9. Paternal inheritance of a 16qh-polymorphism in a patient with repeated IVF failure.Polymorphisms of the size of heterochromatic centromeric regions of chromosomes have been well documented in the human. They appear to have no phenotypic effects in the carriers. However, they appear to be over-represented in infertile couples and those with repeated miscarriages, and there is now growing evidence that they are involved in meiotic pairing, spindle fibre attachment and chromosome movement. Here an analysis of inheritance is reported for a couple presenting with repeated IVF failure in which several embryos were identified as carriers of a polymorphism of the centromeric region of chromosome 16 (16qh-) following aneuploidy screening by sequential fluorescence in-situ hybridization (FISH), using probes for chromosomes 13, 16, 18, 21, 22, X and Y. Detailed cytogenetic analysis by high-resolution banding and FISH of both parents and grandparents established that the polymorphism was familial and inherited from the maternal grandfather. Furthermore, complete analysis of all embryonic nuclei from carrier embryos and others rejected for transfer because of aneuploidy revealed no abnormalities in the segregation pattern of chromosome 16.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
6/9. Detection of fertilization in embryos with accelerated cleavage by fluorescent in-situ hybridization (FISH).Embryos from a couple undergoing routine in-vitro fertilization for unexplained infertility had shown cleavage by day 1 in two consecutive cycles. The response of the woman to fertility drugs had been normal, and there were no known sperm abnormalities. In a subsequent cycle, accelerated cleavage occurred again and we used a modified method of spreading whole embryos and dual fluorescent in-situ hybridization (FISH) with directly labelled probes for chromosomes X and Y to determine if fertilization had occurred in these embryos. Nine oocytes were collected, five of which had cleaved when examined for pronuclei early on day 1 following late insemination. Pronuclei were observed in one of the remaining oocytes, but in this case, three were present. On day 2, all of the oocytes/embryos had cleaved and two were transferred to the patient. The remaining seven were spread for FISH analysis but nuclei were only obtained from five. In three, a Y signal was detected, indicating that fertilization had occurred. In all five embryos, a wide range of x chromosome signals were observed. These data suggest that the embryos had undergone abnormal fertilization and accelerated cleavage.- - - - - - - - - - ranking = 2.5keywords = hybridization (Clic here for more details about this article) |
7/9. The use of fluorescent in-situ hybridization (FISH) for the analysis of in-vitro fertilization embryos: a diagnostic tool for the infertile couple.We use triple colour fluorescent in-situ hybridization (FISH) to sex human embryos for preimplantation diagnosis of X-linked disease, to analyse chromosome numbers in embryos donated for research purposes and as a diagnostic tool for patients undergoing infertility treatment, especially in cases where abnormal embryo development occurs. We have reported on the use of FISH in a case where all embryos showed accelerated cleavage. Here we report on the use of triple colour FISH in a case where five out of seven oocytes were multi-nucleated when examined for pronuclei. The embryos were spread whole using HCl/Tween 20 and triple colour FISH performed with probes for chromosomes X, Y and 1 in a 2 h procedure. Two embryos were normal for the probes used, and three showed abnormalities, including one 4-cell embryo where all nuclei were X,X,X,Y,1,1,1,1. FISH indicated that fertilization had occurred, but that the majority of embryos were abnormal confirming that such embryos should not be considered for transfer. In these cases, or where there is recurrent in-vitro fertilization failure or spontaneous abortions, embryos in future cycles can be examined using FISH to ascertain the level of chromosome abnormality which may aid future infertility treatment.- - - - - - - - - - ranking = 2.5keywords = hybridization (Clic here for more details about this article) |
8/9. Recurrent in vitro fertilization failure evaluated by fluorescence in situ hybridization: a case report.OBJECTIVE: To present a case of IVF failure evaluated by fluorescence in situ hybridization (FISH). DESIGN: Case report. SETTING: research university laboratory and clinical IVF laboratory. PATIENT(S): An infertile couple with recurrent IVF failure. INTERVENTION(S): fluorescence in situ hybridization study of the complete cohort of "zygotes" obtained at the third IVF attempt. MAIN OUTCOME MEASURE(S): fluorescence in situ hybridization studies of chromosomes X, Y, 13, 18, and 21. RESULT(S): All the recovered putative zygotes were abnormal for the expected ploidy, presumably as a result of abnormal oocytes. CONCLUSION(S): fluorescence in situ hybridization techniques represent a promising approach to analyze zygotes that fail to divide normally in vitro and eggs that fail to become fertilized. In cases of recurrent IVF failure, the results of FISH could be used to counsel couples and thus to help them choose among methods other than IVF for assisted reproduction.- - - - - - - - - - ranking = 4keywords = hybridization (Clic here for more details about this article) |
9/9. Conventional and molecular cytogenetic identification of a variant klinefelter syndrome patient with a deleted x chromosome.We report on the case of a 34-year-old patient with the klinefelter syndrome and an unusual cytogenetic finding of a deletion involving the short arm of the x chromosome. This was confirmed with fluorescent in situ hybridization (FISH) using an x chromosome-specific whole chromosome painting probe. The patient presented with infertility. The only abnormal physical findings were atrophic testes with azoospermia and elevated levels of follicle-stimulating hormone and luteinizing hormone. This case represents a relatively mild manifestation of the klinefelter syndrome. Previous reported cases were often associated with more severe phenotypes such as variable degrees of mental retardation and facial dysmorphism, hypothesized as due to the failure of X inactivation. The X inactivation center, located on Xq13, is presumably intact in our patient, who had a deletion involving only the short arm. The mild phenotype observed in our patient was found to be consistent with the conventional and molecular cytogenetic findings.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |