Mitotic and meiotic detection of radiation-induced translocations in mouse stem cell spermatogonia using fluorescencein situ hybridization

The efficiency of two methods of detection of translocations induced in mouse stem cell spermatogonia by X-ray doses of 2, 5 and 7 Gy was compared: classical multivalent analysis at diakinesis-metaphase I of meiosis and observation via fluorescencein situ hybridization analysis of mitotic or meiotic stages. Specific DNA libraries for chromosomes 1, 11 and 13 were used. The results obtained indicate that (a) chromosomes 1, 11 and 13 are more involved in multivalent formation than expected on the basis of DNA content and (b) if the mitotic FISH analysis data are corrected for the observed over-representation, the frequencies of induced translocations are similar to those recorded in the classical multivalent studies, suggesting equal scoring efficiencies in both systems.     

Detection of a human chromosomal translocation t(8;9) in a baby with multiple malformations using two-color fluorescence in situ hybridization

A human chromosomal translocation t(8;9) was detected using two-color fluorescence in situ hybridization with probes capable of staining the entire lengths of each of these chromosomes. The chromosome 8 probe was labeled with biotin and detected with Texas red, while the chromosome 9 probe was labeled with AAF and detected with FITC . In normal metaphase spreads, two metaphases from the proband, two red, one green and one part red and part green derivative chromosome were seen. The bicolor chromosome corresponded to translocation of a chromosome 8 segment to the distal part of the q region of one chromosome 9, as originally indicated by banding analysis. In interphase nuclei of the proband, four domains with bright fluorescence were recognized in many nuclei. Two were red, one was green, and the fourth had portions of both colors, indicating the presence of the translocation.     

A case of type I Gaucher disease with cardiopulmonary amyloidosis and chitotriosidase deficiency

We present a case of Merkel cell carcinoma of the thigh diagnosed by conventional histology, immunohistochemistry, electron microscopy and cytogenetics. A unique chromosome 6 trisomy characterized this primary neoplasm, as confirmed by FISH study. The role of chromosome analysis and interphase cytogenetics is emphasized as an adjunct in the subtyping of tumours and their prognostic evaluation.     

Fluorescence in situ hybridization analysis of two blastomeres from day 3 frozen-thawed embryos followed by analysis of the remaining embryo on day 5

BACKGROUND: Chromosomal mosaicism in human embryos may give rise to false positive or false negative results in preimplantation genetic diagnosis for aneuploidy screening (PGD-AS). Therefore, we have investigated whether the results obtained from a 2-cell biopsy of frozen-thawed embryos and fluorescence in situ hybridization (FISH) analysis are representative for the chromosome constitution of the remaining embryo on day 5. METHODS: Cryopreserved day 3 embryos were thawed and from surviving embryos two blastomeres were biopsied. FISH analysis was performed for chromosomes 1, 7, 13, 15, 16, 18, 21, 22, X and Y. After biopsy, the embryos were cultured until day 5 and further analysed using the same probe panels. RESULTS: In all, 17 embryos were available with a diagnosis based on two blastomeres on day 3 and confirmatory studies on day 5. In 10 of these 17 cases the initial diagnosis could be confirmed. However, in only six cases cytogenetic results were concordant. Besides the 10 cases with a 'correct' diagnosis, there were six false positive results and one false negative, all involving mosaicism. CONCLUSIONS: Investigating the chromosomal constitution of two blastomere nuclei offers a good opportunity to study the incidence of chromosomal mosaicism in early embryo development. The confirmation rate of the results obtained on day 3 depends on the interpretation and is higher when considered from a clinical than from a cytogenetic point of view.     

FISH deletion mapping defines a single location for the Y chromosome stature gene, GCY

At least 1 in 1000 males lacks part of the long arm of the Y chromosome. This chromosomal aberration is often associated with short stature and infertility. Deletion mapping and genotype-phenotype analysis have previously defined two non-overlapping critical regions for growth controlling gene(s), GCY(s), on the euchromatic portion of the Y chromosome long arm. These initial mapping assignments were based on the analysis of patients carrying a pure 46,XYq- karyotype as defined by classical cytogenetic karyotyping. Four genes have been assigned to the distal one of the two critical regions. To determine whether one or both of these two critical regions harbours GCY and whether one of the four genes assigned to the distal region is involved in determination of stature, nine adult patients with Yq chromosomal abnormalities were studied in detail. By PCR and FISH analysis, we showed that all patients with a previously defined pure 46,XYq- karyotype are actually mosaics with cells containing an idic(Y) or ring(Y) chromosome in association with 45,X0 cells. This leads us to conclude that (1) FISH is an absolute prerequisite for the correct identification of Y chromosomal rearrangements and (2) only patients with interstitial Y deletions are reliable predictors for the physical location of stature gene(s) on Yq. Our molecular analyses of chromosomes from patients with interstitial Yq deletions finally establishes the proximal interval between markers DYZ3 and DYS11 as the only GCY critical interval. No functional gene has so far been identified in this region adjacent to the centromere.     

Metachronous and multiple aneurysmal bone cysts: a rare variant of primary aneurysmal bone cysts

In 1942, Jaffe and Lichtenstein introduced the term aneurysmal bone cyst (ABC). Primary ABC is characterized by the presence of spongy or multi-cameral cystic tissue filled with blood. The process is benign, but it is locally destructive and has a high propensity for recurrence. In this paper, we present the third case of multiple metachronous primary ABCs as a rare variant of ABC. We describe the 10-year history of a 12-year-old boy with metachronous multiple primary ABCs at five different sites (right proximal humerus, right ulna, bilateral distal radius and right lateral clavicle). Furthermore, our patient suffered from vascular malformations, such as aortic isthmus stenosis, hypoplastic thoraco-abdominal aorta and bilateral renal artery stenosis. To date, in contrast to solitary ABC, the multiple lesions have been found more frequently in male individuals. Using interphase cytogenetics, we analyzed three of five of the patients ABCs and one of these was also analyzed by GTG-banding. No chromosomal abnormalities were found. Significantly, we excluded the missense mutation of codon 201 in guanine nucleotide-binding protein 1 gene consistently found in McCune-Albright syndrome (MAS) and in non-MAS cases of polyostotic fibrous dysplasia of bone with or without secondary ABC.     

Feasibility of simultaneous fluorescence immunophenotyping and fluorescence in situ hybridization study for the detection of estrogen receptor expression and deletions of the estrogen receptor gene in breast carcinoma cell lines

For the first time, combined immunophenotyping and fluorescence in situ hybridization (FISH) technique according to the ”fluorescence immunophenotyping and interphase cytogenetics as a tool for investigation of neoplasms” (FICTION) technique have been successfully applied in solid tumors. Thus, we were able to visualize the antigen expression of cells with chromosomal deletions of a tumor suppressor region directly. In six breast carcinoma cell lines, we investigated the correlation between estrogen receptor (ER) expression status and deletions of the estrogen receptor gene (ESR). To screen for deletions of the ESR gene, dual-color FISH was performed with a YAC (yeast artificial chromosome) probe containing the ESR gene and, as internal control, with a centromeric probe of chromosome 6. Deletions of the ESR gene were detected in four of six cell lines. For direct comparison of ER expression with the copy number of the ESR gene at the single cell level, immunophenotyping with mouse anti-human ER antibody was combined with FISH with the YAC probe containing the ESR gene according to the FICTION technique. There was no correlation between lack of or reduced ER expression and deletions of the ESR gene. One cell line with deletions of the ESR gene did express ER on the protein level, while another cell line without a deletion did not. Cells with deletions of the ESR gene were either ER expression positive or negative. The staining intensity of ER expression was not associated with the copy number of the ESR gene. Thus, this FICTION study unequivocally shows that deletions of the ESR gene are not the major cause of absent or reduced ER expression in breast carcinoma cell lines. Received: 6 September 1999 / Accepted: 14 September 1999