Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cytogenetics”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Prediction of initial cytogenetic response for subsequent major and complete cytogenetic response to imatinib mesylate therapy in patients with Philadelphia chromosome-positive chronic myelogenous leukemia.

BACKGROUND: Obtaining a major (Philadelphia chromosome [Ph] of < 35%) or a complete cytogenetic response (Ph of 0%) has been associated with excellent long-term survival. Cytogenetic response may continue to improve with therapy. Because early allogeneic stem cell transplantation (SCT) may be associated with a better outcome, early parameters predicting for subsequent cytogenetic responses would optimize the treatment decision-making. METHODS: The current study was performed to analyze whether early cytogenetic responses may be predictive of later major or complete cytogenetic responses to imatinib mesylate therapy in patients with Ph-positive chronic myelogenous leukemia (CML). RESULTS: Two hundred sixty-one patients with Ph-positive, chronic-phase CML after failure with interferon therapy who were treated with imatinib mesylate therapy were analyzed. A persistence of 100% Ph-positive cells after > or = 6 months of imatinib mesylate therapy was associated with a major cytogenetic response rate of 9-13% and a complete cytogenetic response rate of 0-4%. However, a minor cytogenetic response after 3-12 months of therapy still was associated with high rates of major (68-83%) or complete (35-54%) cytogenetic response rates. CONCLUSIONS: Patients with Ph-positive, chronic-phase CML who have persistent 100% Ph-positive disease after > or = 6 months of imatinib mesylate therapy may be offered allogeneic SCT or considered for alternative investigational therapies.

Benzamides↗

Comparison of cytogenetics, interphase cytogenetics, and DNA flow cytometry in bone tumors.

Twenty-three samples of benign and malignant bone tumors were studied with cytogenetic analysis, interphase cytogenetics (IC) using in situ hybridization with (peri)centromeric probes for chromosomes 1, 7, and/or 8, and DNA flow cytometry (FCM). Our aim was to compare these methods in the detection of numerical chromosome aberrations (NCA) and aneuploidy. IC detected aneuploidy in 91%, FCM in 73%, and cytogenetics in 27% of the malignant tumors. In benign tumors IC detected aneuploid by in 4(33%), FCM in 2(17%), and cytogenetic analysis in 1. All of the benign tumors aneuploid by IC, two of which were also aneuploid by FCM, were histologically potentially aggressive. The clonal aberrations detected with cytogenetics usually agreed with the IC and FCM findings. All malignant tumors which had a normal karyotype were aneuploid either by IC or FCM or by both. In conclusion, IC was the most sensitive method in the detection of NCA and aneuploidy even though it was usually performed with only two (peri)centromeric probes. Aneuploidy was detected by cytogenetic analysis alone in 4 samples (17%), by cytogenetic analysis and/or FCM in 11 samples (48%), and by cytogenetic analysis, FCM, and/or IC in 16 samples (70%). Thus, the combined use of all three methods increased the sensitivity of aneuploidy detection.

Aneuploidy↗

[Molecular cytogenetic diagnosis of Klinefelter's syndrome in men more frequently detects sex chromosome mosaicism than classical cytogenetic methods].

BACKGROUND: It was found by classical cytogenetic methods that approximately 80% of X-chromatin positive mates have karyotype 47,XXY and the rest have mosaicism of sex chromosomes. More sensitive molecular-cytogenetic studies allow to evaluate even non-dividing cells of different tissues and therefore they suggest that there could be more frequent occurrence of patients with numerical changes of gonosomes than quoted in the literature. The aim of this study was to detect numerical changes of sex chromosomes by means of double-colour fluorescence in situ hybridisation (FISH) in dividing and non-dividing nuclei of peripheral lymphocytes of males with Klinefelter's syndrome, to compare clinical findings with cytogenetic results, to determine differences in sensitivity of classical and molecular-cytogenetic methods and estimatere the values obtained with controls (healthy males). METHODS AND RESULTS: 26 males with previously diagnosed Klinefelter's sy were examined. Classical cytogenetic studies consisted of evaluation of at least 20 G-banded mitoses of 72 h cultivated peripheral blood. The results we obtained: 19 patients with 47,XXY, 5 mosaics 47,XXY/46,XY, 1 patient mosaic 46,XX/47,XXY and 1 patient 48,XXYY karyotype. The results of double colour FISH and classical cytogenetics were compared and mosaics of cells with normal karyotype 46,XY was found. As a control 10 healthy males were examined and mosaics of gonosomes were not detected. CONCLUSIONS: FISH method has a higher sensitivity for detection of sex chromosomes mosaics than classical cytogenetics. The existence of small cellular side clones with 46,XY karyotype or numerical sex chromosomes changes which were not determined previously can be proved by FISH in patients with Klinefelter's sy.

Cytogenetics↗

Clonal cytogenetic abnormalities in pediatric brain tumors: cytogenetic analysis and clinical correlation.

The use of contemporary techniques in genetics has resulted in identifying a number of recurring abnormalities in pediatric brain tumors. This information has potential significance in the diagnosis and subtyping of these tumors. Although recurring genetic alterations have been identified in specific tumor types, there are some indications that pediatric brain tumors may be different cytogenetically from adult tumors. In addition, cytogenetic aberrations in certain tumors are associated with unfavorable outcome. In this report we present the cytogenetic characteristics of 14 brain tumors. The clinical outcome is correlated with cytogenetic abnormalities. Clonal abnormalities were observed in 6 of 14 (43%) tumors. All 7 cases had abnormalities specific to histologic subtype. Five of 6 cases with clonal abnormalities (83%) and 2 of 8 with a normal karyotype (25%) were observed in patients with poor prognosis. We also describe the cytogenetic aberrations associated with progression in a rare pediatric brain tumor. This data suggests that cytogenetic analysis of pediatric brain tumors may not be entirely different from their adult counterpart and like the latter may be clinically relevant not only in diagnosis but also as a prognostic indicator.

Adolescent↗

Cytogenetic profile in de novo acute myeloid leukemia with FAB subtypes M0, M1, and M2: a study based on 652 cases analyzed with morphology, cytogenetics, and fluorescence in situ hybridization.

In about 55% of acute myeloid leukemia (AML) cases, chromosome aberrations are detectable by cytogenetics. Close correlations between cytomorphology and cytogenetics have been reported. To determine a pattern of cytogenetic abnormalities within the French-American-British (FAB) subtypes AML M0, M1, and M2, we analyzed 48 AML M0, 179 AML M1, and 425 AML M2 and compared cytogenetic data to a cohort of 1,062 AML M3/3v, M4, M4eo, M5a/5b, M6, and M7. Cytogenetic abnormalities were significantly more frequent in AML M0 (71%) compared to M1 (49%), M2 (53%), and the total cohort (56%; P < 0.02). While +8 was the most common numeric abnormality in all FAB subtypes, +13, +14, and +11 were associated with AML M0-M2. The only recurring balanced translocation that was associated with one of these FAB subtypes was t(8;21) in M2 (12.5%) and, rarely, M1 (1.7%) (M0, 0% and M3-7, 0.09%; P=0.001). To evaluate the frequency of cytogenetically undetectable abnormalities, we performed fluorescence in situ hybridization (FISH) analyses in 273 AML M0-M2 with normal karyotype using probes for ETO, ABL, MLL, TEL, RB, P53, AML1, and BCR. In two cases we identified numerical aberrations of RB only in interphases nuclei. In seven additional cases, TEL and MLL abnormalities were found. In conclusion, t(8;21), +11, +13, and +14 are strongly associated with AML M0, M1, and M2. The FISH screening analyses identified abnormalities in an additional 3% in normal karyotypes.

Adolescent↗

Recurrent chromosomal imbalances and structurally abnormal breakpoints within complex karyotypes of malignant peripheral nerve sheath tumour and malignant triton tumour: a cytogenetic and molecular cytogenetic study.

BACKGROUND: Cytogenetic studies of malignant peripheral nerve sheath tumours (MPNSTs) and malignant triton tumours (MTTs) are rare. AIMS: To undertake cytogenetic analysis of these tumours. METHODS: Conventional cytogenetic analysis of 21 MPNSTs and MTTs from 17 patients (nine with peripheral neurofibromatosis (NF1)) was carried out using standard culture and harvesting procedures. For a more precise identification of composite structural rearrangements and marker chromosomes, spectral karyotypic analysis (SKY) was applied to a subset of cases. In addition, EGFR gene copy number was assessed by fluorescence in situ hybridisation (FISH) analysis in a subset of cases. RESULTS: Cytogenetic analysis revealed predominantly complex karyotypes. SKY analysis was useful in further defining many structural anomalies. Structural aberrations most frequently involved chromosomal bands or regions 1p31-36, 4q28-35, 7p22, 11q22-23, 19q13, 20q13, and 22q11-13. Overall, loss of chromosomal material was much more common than gain. Loss of chromosomes or chromosomal regions 1p36 (48%), 3p21-pter (52%), 9p23-pter (57%), 10 (48%), 11q23-qter (48%), 16/16q24 (62%), 17(43%), and 22/22q (48%), and gains of 7/7q (29%) and 8/8q (29%) were most prominent. These gains and losses were distributed equally between MPNST and MTT, demonstrating that these entities are similar with respect to recurrent genomic imbalances. Similarly, none of the recurrent chromosomal breakpoints or imbalances was restricted to either NF1 associated or sporadic MPNSTs. FISH analysis was negative for amplification. CONCLUSIONS: These cytogenetic and molecular cytogenetic findings expand the knowledge of chromosomal alterations in MPNST and MTT, and point to possible recurring regions of interest.

Adolescent↗

Emergence of clonal cytogenetic abnormalities in Ph- cells in some CML patients in cytogenetic remission to imatinib but restoration of polyclonal hematopoiesis in the majority.

Chronic myelogenous leukemia (CML) is characterized by the presence of a Bcr-Abl fusion protein with deregulated tyrosine kinase activity that is required for maintaining the malignant phenotype. Imatinib, a selective inhibitor of Bcr-Abl, induces major cytogenetic remission (MCR) or complete cytogenetic remission (CCR) in the majority of patients with CML in first chronic phase. However, thorough re-evaluation of cytogenetics in a cohort of patients in MCR or CCR demonstrated clonal karyotypic abnormalities in more than 10% of cases, some of which were clinically associated with a myelodysplastic syndrome (MDS). Further analysis identified previous exposure to cytarabine and idarubicin as significant risk factors for the subsequent occurrence of abnormalities in Philadelphia chromosome-negative (Ph-) cells. To investigate if cytogenetically normal but clonal hematopoiesis might be present in other patients in cytogenetic remission, we studied X-chromosome inactivation as a marker of clonality by polymerase chain reaction analysis of the human androgen receptor (HUMARA). We find that imatinib restores a polyclonal pattern in most patients in CCR and MCR. Nonetheless, our results are consistent with the notion that targeted therapy of CML with imatinib favors the manifestation of Ph- clonal disorders in some patients. They indicate that patients on imatinib should be followed with conventional cytogenetics, even after induction of CCR.

Adult↗

Comparison of cytogenetic and molecular cytogenetic detection of chromosome abnormalities in 240 consecutive adult patients with acute myeloid leukemia.

PURPOSE: To prospectively compare cytogenetic and molecular cytogenetic analysis for the detection of the most relevant chromosome abnormalities in a large series of patients with acute myeloid leukemia (AML). PATIENTS AND METHODS: Two hundred forty consecutive adult patients with AML entered onto the multicenter treatment trial AML HD93 were studied. Chromosome banding and fluorescence in situ hybridization (FISH) applying a comprehensive set of genomic DNA probes were performed in a single reference laboratory. RESULTS: Two cases of inv(16), three cases of t(11q23), and three cases of t(8;21)var were only detected by molecular cytogenetics. By FISH, aberrations were identified in three cases with normal karyotypes: inv(16), -Y (in a patient with low metaphase yield on chromosome banding) and a 12p microdeletion. Additional aneuploidies, in particular +8q and +11q, were diagnosed by FISH; however, virtually all these aberrations occurred in patients with complex karyotypes or as an additional abnormality in leukemias with an AML-specific translocation. Finally, aberrations were detected by FISH in eight of 14 patients with no assessable metaphases. CONCLUSION: In most cases of AML, conventional cytogenetic study reliably detects chromosomal abnormalities, and this method should not be replaced by FISH. FISH should be used as a complementary method for the detection of more subtle abnormalities, such as inv(16) and t(11q23), in all patients with newly diagnosed AML and for suspected t(8;21)var. Furthermore, molecular cytogenetics using this comprehensive set of DNA probes provides a valuable diagnostic tool for patients with poor chromosome morphology, low or no yields of metaphase cells, or both.

Acute Disease↗

Novel cytogenetic findings revealed by conventional cytogenetic and FISH analyses in leukaemia patients.

AIM: To describe novel cytogenetic findings in four leukaemia patients. METHODS: Conventional cytogenetic (CC) and fluorescence in situ hybridization (FISH) analyses were performed on bone marrow samples of four leukaemia patients. RESULTS: In this study, t(3;10)(q11;q25) and t(2;22)(p21;q11.2) were detected as novel translocations. t(8;16;21)(q22.1;q13;q22) and t(1;6;9;22)(p36.1;p21.3;q34;q11) were found as variant translocations, and these variant translocations were confirmed by Interphase-FISH and Multi-colour-FISH. CONCLUSION: Newly identified cytogenetic findings can lead us to characterize cytogenetic evolution of the haematological malignancies. Further investigations are certainly warranted to resolve the prognostic impact of these new cytogenetic abnormalities.

Adult↗

Cytogenetic surveillance of workers exposed to genotoxic chemicals: preliminary experiences from a prospective cancer study in a cytogenetic cohort.

Cytogenetic endpoints, conventionally chromosomal aberrations, and later sister chromatid exchanges and micronuclei have long been used to assess exposure of human populations to genotoxic agents. Although the adverse nature of somatic chromosome damage is recognized at the group level, no ill-health manifestations have been causally related to cytogenetic damage at the individual level. In work-related exposures, e.g., ethylene oxide, styrene, benzene, vinyl chloride, and alkylating anticancer agents have been shown to induce somatic chromosomal damage in several studies. For all of these, a carcinogenic risk to humans has also been documented. The possible association of somatic chromosome damage and cancer will be elucidated in a Nordic prospective study. The objective is to find out the significance of a high or low score in any of the cytogenetic parametres to risk of cancer. In the Finnish part of the cohort of 806 individuals, 10 cases of cancer were observed during the first follow-up period. Although the cohort is young and the numbers small, a slightly significant (P = 0.04) trend was observed for individuals with cancer and a score of chromosomal aberrations. No trend was observed for sister chromatid exchanges. The application of cytogenetic surveillance is still not routine methodology, but it is useful and informative in carefully controlled study designs. Special efforts should be directed toward combining different disciplines, i.e., cytogenetics, adduct monitoring, and end-effect epidemiology, in order to reach quantitativeness in risk assessment.

Carcinogens↗

Cytogenetic and molecular cytogenetic findings in dedifferentiated liposarcoma with neural-like whorling pattern and metaplastic bone formation.

Dedifferentiated liposarcoma is a subtype of liposarcoma characterized by juxtaposition of well-differentiated liposarcoma with a nonadipocytic sarcoma. A peculiar form of dedifferentiated liposarcoma has been described, characterized by a nonlipogenic component with a neural-like whorling pattern of growth and metaplastic bone formation. We report the cytogenetic and molecular genetic findings of this peculiar form of dedifferentiation in a retroperitoneal tumor found in a 58-year-old female. The neoplasm had typical histologic findings and a complex karyotype characterized by several numeric and structural chromosomal abnormalities, including the presence of ring and giant rod chromosomes. Molecular cytogenetic studies found high levels of amplification of the MDM2 oncogene, consistent with the amplification of the 12q14 chromosome band, a cytogenetic abnormality commonly found in these tumors. These findings indicate that, despite its unique and peculiar morphologic features, this unusual type of dedifferentiated liposarcoma shares many of the cytogenetic features and molecular genetic abnormalities found in other forms of dedifferentiation. The specific cytogenetics and molecular determinants of these peculiar morphologic findings, however, remain unknown.

Bone and Bones↗

Morphologic, immunologic and cytogenetic studies in erythroleukaemia: evidence for multilineage involvement and identification of two distinct cytogenetic-clinicopathological types.

Clinical features, as well as morphology, immunophenotype and cytogenetics were retrospectively studied in 20 patients with an original diagnosis of erythroleukaemia (EL) reclassified according to the FAB criteria. Fifteen patients had de novo EL, five patients had therapy-related EL. Myelodysplasia preceded the onset of EL in eight cases and myelodysplastic features involving multiple haemopoietic lineages were observed at leukaemia presentation in all cases. Immunologic findings confirmed multilineage involvement, showing sub-population of cells expressing platelet-associated markers in more than 50% of cases tested and the presence of a myelomonocytic component, besides glycophorin A-positive cells. Cytogenetically, major karyotype aberrations (MAKA), defined by the presence of three or more aberrant events in the same clone, were observed in 14 cases, minor karyotype aberrations (MIKA) were observed in four cases and normal karyotype in two cases. No differences in the cytological-cytogenetic picture of our patients with de novo EL, and with therapy-related EL were found suggesting that aetiological factors and/or pathogenetic mechanisms common to EL and secondary leukaemia may exist. All patients with MAKA had leftward shift of erythropoiesis with proerythroblasts and basophilic erythroblasts usually representing more than 50% of all erythroid cells. In patients with MIKA or normal karyotype, maturatio of erythroid cells, though morphologically abnormal, was quantitatively preserved and early erythroblasts never exceeded 25% of erythroid cells. Clinically, the haemoglobin level at presentation, as well as in the proportion of patients achieving complete remission after chemotherapy, appeared to be lower in the maturation arrest-MAKA group as compared to the preserved maturation-MIKA/normal karyotype group. Median survival was shorter in the former group (3.5 months) than in the latter (median 13 months). Morphologic-immunologic-cytogenetic studies thus allow for the identification of two distinct cytogenetic-clinicopathological types of EL.

Adult↗

Extensive analysis of mosaicism in a case of Turner syndrome: the experience of 287 cytogenetic laboratories. College of American Pathologists/American College of Medical Genetics Cytogenetics Resource Committee.

OBJECTIVE: To assemble and interpret karyotype data provided as part of the College of American Pathologists/American College of Medical Genetics Cytogenetics Proficiency Testing Program. DATA SOURCES, EXTRACTION, AND SYNTHESIS: The Cytogenetics Resource Committee requested data on all cells analyzed in a 1994 whole-blood specimen challenge. In that study, 287 participating laboratories analyzed a total of 14297 cells derived from a sample drawn from an adult donor with Turner syndrome. This individual had previously been found to have mosaicism, including cell lines with X structural anomalies along with monosomy X, making this an excellent challenge for a multicenter cytogenetic survey. RESULTS AND CONCLUSIONS: Analysis of the data from this extensive study revealed mosaicism of up to 10 different sex chromosome complements involving the X chromosome with and without a small ring X or a derivative X chromosome. In the routine cytogenetic analysis performed by the participating laboratories, cell lines observed, in decreasing order of prevalence, included 45,X (n = 8357 cells), 46,X,r(X) (n = 3597), 46,X,der(X)t(X;X) (n = 2237), 46,XX (n = 93), 47,X,r(X),r(X) (n = 5), 47,X,der (X)t(X;X),der(X)t(X;X) (n = 3), 47,XX,r(X) (n = 2), and one observation each of 47,XX,der(X)t(X;X), 47,X,der(X)t (X;X),r(X), and 47,XXX. Our molecular cytogenetic data, as well as detailed analysis of G-banded chromosomes, suggest the nomenclature for these 2 abnormal X chromosomes as r(X)(p11.3q21.3) and der(X)t(X;X)(p11.3;q21.3), and we discuss models for the concomitant formation of these 2 entities. Both the degree of analysis and the extensive mosaicism that was discovered in this study are exceptional, and similar reported cases as well as possible mechanisms for the observed X chromosome instability are reviewed.

Adult↗

Cytogenetic abnormalities in 42 rhabdomyosarcoma: a United Kingdom Cancer Cytogenetics Group Study.

BACKGROUND: Rhabdomyosarcomas are the most common type of pediatric soft tissue sarcoma. The cytogenetic literature on RMS is biased towards the less common alveolar subtype (ARMS), which is frequently associated with specific translocations and the PAX3/7-FKHR fusion genes. Relatively few karyotypes are reported for the embryonal subtype (ERMS). The aim of this study was to further cytogenetic knowledge of RMS subtypes. PROCEDURE: Representative examples of all karyotypes from UKCCG; member laboratories were reexamined and their histopathologies reviewed through the United Kingdom Children's Cancer Study (Group) (UKCCSG). Molecular evidence for the PAX3/7-FKHR fusion genes was available for five ERMS and seven ARMS cases and compiled with the karyotypes. RESULTS: Clonal chro mosome aberrations were characterized for 25 ERMS and 17 ARMS cases. Thirty-six percent of the ERMS cases involved translocation breakpoints in the 1p11-q11 region. Ten of the seventeen cases of ARMS showed cytogenetic evidence for the t(2;13)(q35;q14), consistent with molecular data available from four of these. Two further ARMS cases revealed a PAX3-FKHR and a variant PAX7-FKHR fusion gene product that were not detected cytogenetically. CONCLUSIONS: Many of the karyotypes from both subtypes were complex. The frequent involvement of the 1p11-1q11 region and gain of chromosomes 2, 8, 12, and 13 in ERMS may be functionally significant. There was no evidence for involvement of the PAX3/7-FKHR genes in ERMS, and cryptic involvement was found in some ARMS. There were no consistent chromosomal rearrangements associated with apparently translocation negative ARMS cases.

Adolescent↗

[Numerical chromosome aberrations in abortion tissue. Comparison of conventional cytogenetics and interphase cytogenetics in paraffin sections and nuclear suspensions].

Chromosomal aberrations are an important cause of spontaneous abortions. In order to detect numerical aberrations, paraffin-embedded tissue from 26 abortions with known conventional cytogenetic findings (CCG; 25 numerical aberrations and one partial trisomy 7p) was analyzed by means of interphase cytogenetics (ICG) using centromer-specific DNA probes for chromosomes #X, #Y, #10, #18, and #13/#21. Limit-values for the diagnosis of aneusomy in tissue sections were established by classifying the distribution of hybridization signals by CCG data (for gain > or = 15% of nuclei with +1 signal; for deletion > 40% of nuclei with -1 signal). Signal distribution in tissue sections and nuclear suspensions from paraffin blocks analyzed in parallel showed statistically a highly significant correlation (P < 0.0001). ICG and CCG diagnoses corresponded in 18 of 20 cases suitable for evaluation (90%; no false-positive result). No correlation between cytogenetic and histologic findings could be found. ICG proved to be a reliable tool for the detection of numerical chromosomal aberrations in paraffin-embedded tissue of abortions (sections and nuclear suspensions). This, data for genetic counselling of the parents can be provided. The limit values for diagnosis of aneusomy could also be important for the application of ICG in tumor cytogenetics.

Abortion, Spontaneous↗

Cytogenetic triclonality in T-cell acute lymphoblastic leukemia: a conventional and molecular cytogenetic study.

Cytogenetically-unrelated clones are infrequently seen in hematologic malignancies, and are particularly uncommon in acute lymphoblastic leukemia. We report a case of T-cell acute lymphoblastic leukemia with L2 morphology which demonstrated three cytogenetically distinct clones: 46,XY,t(2;9)(p21;q34)/46,XY,del(6)(q21q23)/47,XX,+8. Interphase cytogenetic analysis by fluorescence in situ hybridization (FISH) confirmed the presence of trisomy 8 in a significant proportion of lymphoblasts, while reverse transcription-polymerase chain reaction (RT-PCR) did not show the presence of BCR/ABL fusion. This is the first report describing the occurrence of cytogenetic triclonality in de novo T-cell acute lymphoblastic leukemia.

Child↗

Cytogenetic and molecular cytogenetic findings in 43 aneurysmal bone cysts: aberrations of 17p mapped to 17p13.2 by fluorescence in situ hybridization.

Aneurysmal bone cyst is a benign, cystic lesion of bone composed of blood-filled spaces separated by fibrous septa. Relatively few cases of aneurysmal bone cyst have been cytogenetically characterized, yet abnormalities of the short arm of chromosome 17 appear to be recurrent. In this study, conventional cytogenetic analysis of 43 aneurysmal bone cyst specimens from 38 patients over a 12-year period revealed clonal chromosomal abnormalities in 12 specimens. Karyotypic anomalies of 17p, including a complex translocation and inversion, were identified in eight of these 12 specimens. In an effort to further define the aberrant 17p breakpoint, fluorescence in situ hybridization (FISH) analyses were performed using a series of probe combinations spanning a 5.1 Mb region between the TP53 (17p13.1) and Miller-Dieker lissencephaly syndrome (17p13.3) gene loci. These studies revealed the critical breakpoint locus at 17p13.2, flanked proximally by an RP11-46I8, RP11-333E1, and RP11-457I18 bacterial artificial chromosome (BAC) probe cocktail and distally by an RP11-198F11 and RP11-115H24 BAC and RP5-1050D4 P1 artificial chromosome (PAC) probe cocktail. Overall, abnormalities of the 17p13.2 locus were identified by metaphase and/or interphase cell FISH analysis in 22 of 35 (63%) aneurysmal bone cyst specimens examined including 26 karyotypically normal specimens. These cytogenetic and molecular cytogenetic findings expand our knowledge of chromosomal alterations in aneurysmal bone cyst, further localize the critically involved 17p breakpoint, and provide an alternative approach (ie FISH) for detecting 17p abnormalities in nondividing cells of aneurysmal bone cysts. The latter could potentially be utilized as an adjunct in diagnostically challenging cases.

Adult↗

Cytogenetics and molecular cytogenetics in Hodgkin's disease.

For about 20 years we have known from cytogenetic studies that there is a clonal cell population in Hodgkin's disease. Most karyotypes are complexly aberrant and chromosome numbers typically lie in the hyperploid range. Some chromosome regions seem to be preferentially involved, but a chromosome aberration specific for Hodgkin's disease has not yet been determined. Although the existence of a clonal cell population is evident from these cytogenetic studies, there is still an ongoing debate, whether in all cases the pathognomonic Hodgkin and Reed-Sternberg cells belong to one single aberrant clone and thus represent a monoclonal proliferation. This article reviews the current knowledge on cytogenetics in Hodgkin's disease. Moreover, our recent data from simultaneous immunophenotyping and interphase cytogenetics (FICTION) are introduced into the passionate discussion on the monoclonality of the Hodgkin and Reed-Sternberg cells.

Chromosome Aberrations↗