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Interphase FISH (interphase + fish)

Distribution by Scientific Domains

Life Sciences	60%
Medical Sciences	40%

Selected Abstracts

Quantitative FISH analysis on interphase nuclei may improve diagnosis of DNA diploid breast cancers

DIAGNOSTIC CYTOPATHOLOGY, Issue 4 2002
Khuong Truong
Abstract The detection of DNA aneuploid cells using flow cytometry is an indication for the presence of tumor cells, but when DNA diploid cells are found in 25,33% of the cases, the diagnostic and prognostic significance of DNA ploidy is more limited. We analyzed interphase nuclei after in situ hybridization and using image cytometry on 50 breast tumors with diploid DNA content to investigate whether early chromosome rearrangements were detectable and if their occurrence was clinically significant. Imbalances between the two arms of chromosome 1 were found in 55% of the cases and values ranged from 1.5,3.0. Comparison with histological data showed that Grade I tumors mainly have imbalances (67%) and that Grade III tumors were mainly without the imbalance (67%), whereas Grade II tumors were intermediate (50% imbalance). These data suggest that the diagnosis of DNA diploid cases may be improved by using interphase FISH. In addition, the data also indicates that early breast tumors may have different genetic origins, which is important in the comprehension of tumor malignancy in early stages, especially for preinvasive lesions. Diagn. Cytopathol. 2002;26:213,216. © 2002 Wiley-Liss, Inc. [source]

Inversion of the Williams syndrome region is a common polymorphism found more frequently in parents of children with Williams syndrome,

AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 2 2010
Holly H. Hobart
Abstract Williams syndrome (WS) is a multisystem disorder caused by deletion of about 1.55,Mb of DNA (including 26 genes) on chromosome 7q11.23, a region predisposed to recombination due to its genomic structure. Deletion of the Williams syndrome chromosome region (WSCR) occurs sporadically. To better define chance for familial recurrence and to investigate the prevalence of genomic rearrangements of the region, 257 children with WS and their parents were studied. We determined deletion size in probands by metaphase FISH, parent-of-origin of the deleted chromosome by molecular genetic methods, and inversion status of the WSCR in both parents by interphase FISH. The frequency of WSCR inversion in the transmitting parent group was 24.9%. In contrast, the rate of inversion in the non-transmitting parent group (a reasonable estimate of the rate in the general population) was 5.8%. There were no significant gender differences with respect to parent-of-origin for the deleted chromosome or the incidence of the inversion polymorphism. There was no difference in the rate of spontaneous abortion for mothers heterozygous for the WSCR inversion relative to mothers without the inversion. We calculate that for a parent heterozygous for a WSCR inversion, the chance to have a child with WS is about 1 in 1,750, in contrast to the 1 in 9,500 chance for a parent without an inversion. © 2010 Wiley-Liss, Inc. [source]

Resolution of trisomic mosaicism in prenatal diagnosis: estimated performance of a 50K SNP microarray

PRENATAL DIAGNOSIS, Issue 13 2007
Jillian Cross
Abstract Objective To evaluate the ability of a DNA single nucleotide polymorphism (SNP) microarray to detect chromosome mosaicism for trisomy in prenatal samples in order to compare this with conventional cytogenetics. Method We created a dilution series of mock mosaic samples, by mixing measured amounts of fibroblast cells containing trisomy 8 from a male with aliquots of cells with a normal female karyotype. DNAs were extracted from these mosaic mixtures, then analysed on the Affymetrix 50K Xba SNP chip. Duplicate aliquots of each mosaic sample were probed using interphase FISH, with centromeric probes for chromosomes X, Y and 8, to estimate independently the proportion of male trisomy 8 in each sample. Data from the arrays were analysed using publicly available analysis tools. Statistical calculations were then performed using a Student's t -test to determine if there was a significant difference between the copy numbers of each chromosome. Results These experiments using the Affymetrix 50K Xba SNP microarray showed mosaicism to be obvious at 20% and with additional statistical calculations, the lower limit for detection is about 10%. Conclusion The SNP microarray platform tested can detect mosaicism for trisomy in prenatal samples at levels comparable with conventional cytogenetic techniques in routine use. Copyright © 2007 John Wiley & Sons, Ltd. [source]

False-positive prenatal diagnosis of trisomy 18 by interphase FISH: Hybridization of chromosome 18 alpha-satellite DNA probe (D18Z1) to the heterochromatic region of chromosome 9

PRENATAL DIAGNOSIS, Issue 11 2007
Sainan Wei
No abstract is available for this article. [source]

The selective use of rapid aneuploidy screening in prenatal diagnosis

AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 1 2009
Jan E. DICKINSON
Aims: To evaluate the diagnostic utility and costing of the selective use of rapid aneuploidy screening (RAS) for chorion villus sampling (CVS) and amniocentesis specimens. Methods: CVS and amniocenteses performed between 2000 and 2006 were identified. Cases were subdivided into two groups: (i) RAS in addition to long-term culture and (ii) long-term chromosome culture alone. The frequency of RAS, the proportion of abnormal results and the cytogenetic costings were reviewed. Results: A total of 3315 procedures were performed: 730 CVS and 2585 amniocenteses. An abnormal karyotype culture was present in 366 of 3315 (11%). For CVS an abnormal culture was present in 164 (22.5%). RAS (short-term culture/direct preparation) was selectively used in 399 cases (54.6%) with an abnormal result in 128 (32% of RAS). For amniocentesis, 206 chromosome abnormalities were present (8.0% of specimens). RAS (interphase FISH) was selectively used in 580 amniocenteses (22.4%). FISH was requested in 95 (66.4%) of the 143 abnormal cases potentially detectable with standard probes. There was a progressive increase in utilisation of RAS for amniocentesis (8.9% in 2000 to 43.3% of cases in 2006, P < 0.001). CVS RAS was stable. This liberalisation resulted in a fourfold increase in expenditure for FISH and cost/abnormality detected ($A970 per abnormal result in 2000 to $A4015 per abnormal result in 2006). Conclusion: The selective use of prenatal RAS results in a reasonably high detection rate for chromosomal anomalies. Liberalisation of RAS, however, is an expensive cytogenetic model. An approach based on some predictive level of risk combined with resource funding levels may be a more pragmatic approach. [source]