1/39. A malignant triton tumor with an unbalanced translocation (1;13)(q10;q10) and an isochromosome (8)(q10) as the sole karyotypic abnormalities.The karyotype of a malignant nerve sheath tumor with rhabdomyosarcomatous differentiation (malignant triton tumor) of a 58-year-old woman is reported. The tumor revealed an isochromosome for the long arm of chromosome 8 and an unbalanced translocation (1;13)(q10;q10) leading to a gain of the long arm of chromosome 1 as the sole karyotypic abnormalities.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
2/39. Molecular mapping of an idic(Yp) chromosome in an Ullrich-Turner patient.We describe a woman with Ullrich-Turner manifestations and a 45,X/46, X, mar karyotype. fluorescence in situ hybridization (FISH) and dna analysis were carried out in order to determine the origin and structure of the marker. FISH showed that the marker was a Y-derived dicentric chromosome. The breakpoint at Yq11 (interval 6) was mapped using Southern blotting and polymerase chain reaction (PCR). There were no nucleotide alterations in the SRY conserved domain. Histological analysis of the gonads showed an ovarian-like stroma with no signs of testicular tissue. These findings indicate that the patient was a mosaic 45,X/46,X,idic(Yp) whose phenotypic expression, including sex determination, appeared to have had more influence from the 45,X cell line.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
3/39. Isodicentric y chromosome in an Ullrich-Turner patient without virilization.We report on a 17-year-old young woman with Ullrich-turner syndrome (UTS), who was found to have a karyotype 45,X/46,X,idic(Y)(q11). She had age-appropriate genitalia without virilization in spite of the presence of the Y-derived marker chromosome and SRY locus in 70% of her lymphocytes. Having reviewed the literature, we conclude that a possible explanation for the lack of virilization in these mosaic patients is most likely an uneven distribution of tissue mosaicism (gonadal mosaicism).- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
4/39. An isochromosome 6p in a primary meningeal malignant melanoma.The rearrangement of chromosome 6, particularly the deletion of 6q, has been observed in human malignant melanoma with or without brain metastases. The isochromosome 6p has also been described. In this study, we report the cytogenetic analysis of a primary malignant melanoma of the central nervous system. Its dominating karyotype was 47,XX, i(6)(p10). fluorescence in situ hybridization (FISH), using a 6p chromosome arm probe, confirmed the structure of the isochromosome. To our knowledge, this is the first report of this type of chromosomal aberration in an uncommon neoplasm of leptomeningeal melanocytic origin.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
5/39. Three probands with autistic disorder and isodicentric chromosome 15.We have identified three unrelated probands with autistic disorder (AD) and isodicentric chromosomes that encompass the proximal region of 15q11.2. All three probands met the diagnostic and statistical manual of mental disorders, fourth edition [DSM-IV; American Psychiatric association, 1994], and international classification of diseases ( ICD-10) diagnostic criteria for AD, confirmed with the Autism Diagnostic interview -Revised (ADI-R). Chromosome analysis revealed the following karyotypes: 47,XX, idic(15)(q11.2), 47,XX, idic(15) (q11.2), and 47,XY, idic(15)(q11.2). Haplotype analysis of genotypic maker data in the probands and their parents showed that marker chromosomes in all three instances were of maternal origin. Comparison of the clinical findings of the three AD probands with case reports in the published literature (N = 20) reveals a clustering of physical and developmental features. Specifically, these three probands and the majority of reported probands in the literature exhibited hypotonia (n = 13), seizures (n = 13), and delayed gross motor development (n = 13). In addition, clustering of the following clinical signs was seen with respect to exhibited speech delay (n = 13), lack of social reciprocity (n = 11), and stereotyped behaviors (n = 12). Collectively, these data provide further evidence for the involvement of chromosome 15 in AD as well as present preliminary data suggesting a clustering of clinical features in AD probands with proximal 15q anomalies.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
6/39. Isochromosome (7)(q10) in Shwachman syndrome without MDS/AML and role of chromosome 7 anomalies in myeloproliferative disorders.Shwachman syndrome (SS) is an autosomal recessive disorder in which bone marrow dysfunction is observed, with development of myelodysplastic syndromes (MDS) and acute myeloid leukemias (AML) in up to one third of the cases. Inconclusive data are available as to increased chromosome breakage in SS, while chromosome 7 anomalies, and often an isochromosome (7)(q10), are frequent in cases with MDS/AML. We report on the consistent presence of an i(7)(q10) in the bone marrow and blood lymphocytes in one of two sisters affected with SS without any clinical or cytological signs of MDS/AML. Thus, this patient was either a case of constitutional mosaicism for the i(7)(q10), or this had to be acquired in a nondysplastic and non-neoplastic marrow clone. dna polymorphism analysis demonstrated the paternal origin of the i(7q). We postulate that the SS mutation acts as a mutator gene, and causes karyotype instability; abnormal clones would thus arise in the marrow, and chromosome 7 anomalies, i(7q) in particular, will in turn lead to MDS/AML. If this interpretation is correct, it would be also an indication to consider chromosome 7 anomalies in general, out of SS, as primary changes in MDS/AML pathogenesis.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
7/39. Chromosomal mosaicism for isochromosome 11q confined to CVS direct preparations.OBJECTIVE: To analyse the discrepancy between the karyotype in direct preparations of chorionic villus sampling (CVS) and the fetal karyotype and its possible fetal phenotypic repercussion. methods: The karyotype was obtained from direct and cultured preparations of CVS. FISH was performed in direct CVS preparations and in four different areas of term placenta. RESULTS: karyotype and FISH analysis in CVS revealed a 46,XX/47,XX, i(11q) cell line. Cultured CVS preparations showed a 46,XX karyotype. Cytogenetic studies in term placenta did not reveal the abnormal cell line. Molecular studies did not detect uniparental disomy for chromosome 11 in the fetus. CONCLUSION: The fetus, at birth, had no phenotypic abnormalities. IUGR was not present during gestation, in accordance with the low proportion of aneuploid cells in term placenta, and UPD for chromosome 11 was not observed.- - - - - - - - - - ranking = 4keywords = karyotype (Clic here for more details about this article) |
8/39. Isochromosome consisting of terminal short arm and proximal long arm X in a girl with short stature.A 16-year-old girl with short stature, short neck, shield chest, and cubitus valgus was studied. FISH analyses of her structurally altered x chromosome showed a der(X)- (wcpX ,TelXp/Yp ,SHOX ,STS ,KAL-, 37A12-,DXZ1 ,XIST ,97L7 ,300O13-,404F- 18-,417G15-,404F18-,140A-,TelXq/Yq-). These results, together with the high-resolution banding analysis, indicated her karyotype to be 46,X,der(X)(Xpter-->Xp22.3::Xq22.3--> cen-->Xq22.3::Xp22.3-->Xpter). The der(X) was an isochromosome, consisting of duplicated terminal short arms and duplicated proximal long arms. This in turn suggested that the chromosome was formed through pericentric inversion of an x chromosome, followed by isochromosome formation through sister chromatid exchange at Xp, close to the centromere. Replication R-banding analysis showed that the abnormal x chromosome was late replicating. Analysis of digestion patterns with a methylation-sensitive restriction endonuclease of the phosphoglycerate kinase 1 gene, located in Xq13.3, indicated that its inactivation patterns were completely skewed.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
9/39. Cytogenetic and molecular characterization of two isodicentric Y chromosomes.We report the results of detailed molecular-cytogenetic studies of two isodicentric Y [idic(Y)] chromosomes identified in patients with complex mosaic karyotypes. We used fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) to determine the structure and genetic content of the abnormal chromosomes. In the first patient, classical cytogenetics and FISH analysis with y chromosome-specific probes showed in peripheral blood lymphocytes a karyotype with 4 cell lines: 45,X[128]/46,X, idic(Y)(p11.32)[65]/47,XY, idic(Y)(p11.32)[2]/47,X, 2idic(Y)(p11. 32)[1]. No y chromosome material was found in the removed gonads. For precise characterization of the Yp breakpoint, FISH and fiberFISH analysis, using a telomeric probe and a panel of cosmid probes from the pseudoautosomal region PAR1, was performed. The results showed that the breakpoint maps approximately 1,000 Kb from Ypter. The second idic(Y) chromosome was found in a boy with mild mental retardation, craniofacial anomalies, and the karyotype in lymphocytes 47,X, idic(Y)(q11.23), i(Y)(p10)[77]/46,X, i(Y)(p10)[23]. To our knowledge, such an association has not been previously described. FISH and PCR analysis indicated the presence of at least two copies of the SRY gene in all analyzed cells. Using 17 PCR primers, the Yq breakpoint was shown to map between sY123 (DYS214) and sY121 (DYS212) loci in interval 5O in AZFb region. Possible mechanisms of formation of abnormal Y chromosomes and karyotype-phenotype correlations are discussed.- - - - - - - - - - ranking = 4keywords = karyotype (Clic here for more details about this article) |
10/39. Isochromosome (17)(q10) as the sole structural chromosomal rearrangement in a case of botryoid rhabdomyosarcoma.We describe a case of botryoid rhabdomyosarcoma with the karyotype 53,XX, 2, 5, 8, 12, 13, i(17)(q10), 19, 20. Only two cytogenetically analyzed cases of this tumor were previously reported and structural chromosomal abnormalities in each tumor were different.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
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