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Balanced Translocation (balanced + translocation)

Distribution by Scientific Domains

Medical Sciences	82%
Life Sciences	17%

Selected Abstracts

Balanced translocation in a patient with severe myoclonic epilepsy of infancy disrupts the sodium channel gene SCN1A

EPILEPSIA, Issue 6 2008
Rikke S. Møller
Summary In a patient with severe myoclonic epilepsy of infancy (SMEI), we identified a de novo balanced translocation, t(2;5)(q24.3,q34). The breakpoint on chromosome 2q24.3 truncated the SCN1A gene and the 5q34 breakpoint was within a highly conserved genomic region. Point mutations or microdeletions of SCN1A have previously been identified in SMEI patients, but this is the first report of a balanced translocation disrupting the SCN1A gene in an epilepsy patient. We therefore recommend that SMEI patients without SCN1A microdeletions or point mutations should be investigated for chromosomal rearrangements. [source]

PNET-like features of synovial sarcoma of the lung: A pitfall in the cytologic diagnosis of soft-tissue tumors

DIAGNOSTIC CYTOPATHOLOGY, Issue 4 2001
Pascale Hummel M.D.
Abstract Fine-needle aspiration (FNA) cytology of soft-tissue tumors is evolving. As more experience is gained, we are becoming aware of potential pitfalls. We describe 2 cases of synovial sarcoma of the lung, primary and metastatic, in patients who had FNA biopsy performed on a lung mass. The cytologic smears showed extremely cellular groups of malignant small round cells, intersected by small blood vessels, with numerous loose single cells, in a background of macrophages and mature lymphocytes. The tumors displayed monomorphic cells forming rosettes and displaying occasional mitoses. A diagnosis of neuroendocrine tumor/primitive neuroepithelial tumor (PNET) was suspected. Furthermore, this suspicion was supported by immunohistochemical stains, which showed positivity for a neuroendocrine marker, Leu 7 (case 1), and for a neural marker, CD 99 (O 13 or HBA 71) (both cases); and negativity for cytokeratins (case 1). The resection specimen of case 1 had mostly tightly packed small round cells, with occasional rosettes, similar to the FNA biopsy, and focal areas composed of spindle cells, organized in a focal fibrosarcoma-like and hemangiopericytoma-like pattern. A balanced translocation between chromosomes X and 18, demonstrated by both karyotyping and fluorescent in situ hybridization (FISH), enabled us to make a diagnosis of synovial sarcoma, which was histologically classified as poorly differentiated. Case 2 was a metastatic biphasic synovial sarcoma of the arm, with a prominent epithelial component. Synovial sarcoma, when composed mainly of small round cells on cytologic smears, is a great mimicker of neuroendocrine/PNET tumors, with light microscopic and immunohistochemical overlap. Awareness of this potential pitfall may aid in preventing a misdiagnosis. Its recognition is of major concern, especially for the poorly differentiated variant, because it is associated with a worse prognosis. Diagn. Cytopathol. 24:283,288, 2001. © 2001 Wiley-Liss, Inc. [source]

Balanced translocation in a patient with severe myoclonic epilepsy of infancy disrupts the sodium channel gene SCN1A

Breakpoint of a balanced translocation (X:14) (q27.1;q32.3) in a girl with severe hemophilia B maps proximal to the factor IX gene

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2004
J. Di Paola
Summary., Hemophilia B is an X-linked bleeding disorder caused by the deficiency of coagulation factor (F)IX, with an estimated prevalence of 1 in 30 000 male births. It is almost exclusively seen in males with rare exceptions. We report a girl who was diagnosed with severe (<1%) FIX deficiency at 4 months of age. Cytogenetic studies in the patient showed a balanced translocation between one of the X-chromosomes and chromosome 14, with breakpoints at bands Xq27.1 and 14q32.3. Both parents were found to have normal chromosomes. Late replication studies by incorporation of 5-bromodeoxyuridine showed non-random inactivation of the normal X-chromosome, a phenomenon frequently seen in balanced X/autosome translocations. To map the breakpoint, fluorescent in-situ hybridization was performed. A PAC DNA probe, RP6-88D7 (which contains the FIX gene) hybridized only on the normal chromosome X as well as onto the derivative 14. Using a PAC DNA probe, RP11-963P9 that is located proximal to the FIX gene, we obtained signals on the normal and derivative X and also on the derivative 14. We conclude that the breakpoint is located within the DNA sequence of this clone mapping proximal to the FIX gene. Since the FIX gene seems to be intact in the derivative 14, the breakpoint may affect an upstream regulatory sequence that subjects the gene to position effect variegation (PEV). [source]

Chorionic villus sampling (CVS) and fluorescence in situ hybridization (FISH) for a rapid first-trimester prenatal diagnosis

PRENATAL DIAGNOSIS, Issue 4 2004
Carole Goumy
Abstract Objectives Early diagnosis of unbalanced chromosomal abnormalities can be crucial in minimizing the trauma caused by an elective abortion. Chorionic villus sampling (CVS) can be performed from 9 weeks of gestation. However, two major problems are encountered in fetal karyotyping using cultured cells from chorionic villi: the relatively slow growth of these cells in culture, which delays the diagnosis, and the occurrence of maternal cell contamination (MCC). With FISH, a result can be obtained within 24 h, and, as no cell culturing is involved, the problem of MCC is minimized. Methods Thirty-two women undergoing CVS between 9 and 12 weeks of gestation were offered FISH analysis in addition to the standard chromosome analysis. Results FISH was informative in all of the cases tested. Eleven aneuploidies were detected in cases of hygroma or abnormal nuchal translucency and two out of four fetuses from parental translocation were unbalanced. The decision to perform early termination of these chromosomally abnormal pregnancies was based on FISH results and ultrasound abnormalities, without waiting for karyotype results. Conclusion The present study confirms that the association of FISH and CVS allows a rapid and early prenatal diagnosis, and emphasizes that this association is of great benefit in cases of known parental balanced translocation or when hygroma is detected by ultrasonography. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Lupus-like disease and high interferon levels corresponding to trisomy of the type I interferon cluster on chromosome 9p

ARTHRITIS & RHEUMATISM, Issue 5 2006
Haoyang Zhuang
Objective Systemic lupus erythematosus (SLE) is associated with type I interferons (IFNs) and can be induced by IFN, treatment. This study looked for evidence of autoimmunity in a pedigree consisting of 4 family members with a balanced translocation 9;21 and 2 members with an unbalanced translocation resulting in trisomy of the short (p) arm and part of the long (q) arm of chromosome 9. These latter 2 subjects had 3 copies of the IFN gene cluster. Methods Subjects were evaluated clinically and serologically for autoimmune disease. Expression levels of IFN,4, IFN,, the type I IFN,inducible gene Mx1, the type I IFN receptor, interleukin-6, and tumor necrosis factor , were determined by real-time polymerase chain reaction. Circulating plasmacytoid dendritic cells, the main IFN-producing cells, were quantified by flow cytometry. Results Both subjects with trisomy of chromosome 9p had a lupus-like syndrome with joint manifestations and antinuclear antibodies: one had anti-RNP and antiphospholipid autoantibodies, and the other had anti,Ro 60. The 3 family members with a balanced translocation 9;21 had no clinical or serologic evidence of autoimmunity, similar to that in relatives who were unaffected by the chromosomal translocation. In the 2 subjects with trisomy of 9p, high levels of IFN,/, (comparable with those found in patients with SLE), increased signaling through the IFN receptor (as indicated by high Mx1 expression), and low levels of circulating plasmacytoid dendritic cells (as observed in patients with SLE) were evident. These abnormalities were not seen in individuals with a balanced translocation. Conclusion Trisomy of the type I IFN cluster of chromosome 9p was associated with lupus-like autoimmunity and increased IFN,/, and IFN receptor signaling. The data support the idea that abnormal regulation of type I IFN production is involved in the pathogenesis of SLE. [source]

13q33.2 deletion: a rare cause of ambiguous genitalia in a male newborn with growth restriction

ACTA PAEDIATRICA, Issue 5 2010
JH Andresen
Abstract 13q deletion is a rare cause of ambiguous genitalia in the male newborn, and can be associated with mental retardation of varying degree, retinoblastoma, and malformations of the brain, eye, genitourinary and gastrointestinal tract, depending on the level of the deletion. We present a male neonate with ambiguous genitalia and IUGR with a 13q33.2 deletion, and a paternal balanced translocation. Microarray analysis found the genes involved to be on chromosome 13 in the region 102989254bp,109214509bp. This deletion encompasses the EFNB2 gene, which has been implicated in genital malformations in 13q deletion cases. Conclusions:, We find a link between haploinsufficiency of the EFNB2 gene and the presence of ambiguous genitalia and hypospadia in patients with a 13q.33 deletion. This work emphasizes the importance of early diagnosis of this condition due to the link with mental retardation and the need for follow up and management. [source]

Hypocalcemia impacts heart failure control in DiGeorge 2 syndrome

ACTA PAEDIATRICA, Issue 1 2009
Pei-Hsin Chao
Abstract Chromosome 10p terminal deletion accounts for a rare subset among patients presenting with DiGeorge syndrome, and is designated as DiGeorge 2 syndrome. We report a neonate with DiGeorge-like phenotype having a deletion of distal 10p (p13-pter) and a duplication of terminal 3q (q29-qter) derived from paternal balanced translocation between 3q29 and 10p13. She had facial dysmorphism, atrial and ventricular septal defect, impaired T-cell function, hypoparathyroidism, sensorineural hearing loss, renal abnormalities and developmental delay. Her phenotype corresponded well with the typical characteristics of partial monosomy 10p and the small duplication of terminal 3q did not involve the critical region of 3q duplication syndrome. Clinically, hypoparathyroidism-related hypocalcemia lasted for three weeks and resulted in repeated episodes of heart failure. It was not until the calcium level was normalized that her heart failure improved markedly. Conclusion: Cytogenetic analysis can help to recognize patients early on who have terminal 10p deletion when microdeletion of 22q11.2 is not the cause of DiGeorge syndrome. Hypoparathyroidism-related hypocalcemia impacts heart failure control in partial monosomy 10p and should be managed aggressively on critical care. [source]

High resolution analysis of follicular lymphoma genomes reveals somatic recurrent sites of copy-neutral loss of heterozygosity and copy number alterations that target single genes,

GENES, CHROMOSOMES AND CANCER, Issue 8 2010
K-John J. Cheung
A multiplatform approach, including conventional cytogenetic techniques, BAC array comparative genomic hybridization, and Affymetrix 500K SNP arrays, was applied to the study of the tumor genomes of 25 follicular lymphoma biopsy samples with paired normal DNA samples to characterize balanced translocations, copy number imbalances, and copy-neutral loss of heterozygosity (cnLOH). In addition to the t(14;18), eight unique balanced translocations were found. Commonly reported FL-associated copy number regions were revealed including losses of 1p32-36, 6q, and 10q, and gains of 1q, 6p, 7, 12, 18, and X. The most frequent regions affected by copy-neutral loss of heterozygosity were 1p36.33 (28%), 6p21.3 (20%), 12q21.2-q24.33 (16%), and 16p13.3 (24%). We also identified by SNP analysis, 45 aberrant regions that each affected one gene, including CDKN2A, CDKN2B, FHIT, KIT, PEX14, and PTPRD, which were associated with canonical pathways involved in tumor development. This study illustrates the power of using complementary high-resolution platforms on paired tumor/normal specimens and computational analysis to provide potential insights into the significance of single-gene somatic aberrations in FL tumorigenesis. © 2010 Wiley-Liss,Inc. [source]

Mutations of the PTPN11 gene in therapy-related MDS and AML with rare balanced chromosome translocations

GENES, CHROMOSOMES AND CANCER, Issue 6 2007
Debes H. Christiansen
Activating mutations of the PTPN11 gene encoding the SHP2 tyrosine phosphatase is the most common genetic abnormality in juvenile myelomonocytic leukemia and is sporadically observed in myelodysplasia (MDS) and acute myeloid leukemia (AML). An unselected series of 140 patients with therapy-related MDS or AML were investigated for mutations of PTPN11 in Exons 3, 4, 8, and 13. Four cases had mutations of the gene; three of these had deletions or loss of chromosome arm 7q. Two cases had rare balanced translocations to chromosome band 21q22 with rearrangement of the RUNX1 gene and the other two patients had rare balanced translocations to chromosome band 3q26 with rearrangement of the EVI1 gene. The findings support cooperation between so called Class I and Class II mutations in leukemogenesis. © 2007 Wiley-Liss, Inc. [source]

Multiplex fluorescence in situ hybridization in identifying chromosome involvement of complex karyotypes in de novo myelodysplastic syndromes and acute myeloid leukemia

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1p1 2010
W. XU
Summary Complex chromosomal aberrations (CCA) can be detected in a substantial proportion of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), which are associated with very poor prognosis. Conventional cytogenetics (CC) cannot accurately define the specific alterations in CCA. Multiplex fluorescence in situ hybridization (M-FISH) allows the comprehensive identification of CCA. In this study, M-FISH was used in 16 patients with de novo MDS and 22 with AML with CCA detected by R-banding CC, and revealed 206 aberrations involved all 24 chromosomes, including 73 numerical chromosomal abnormalities and 133 structural abnormalities. The chromosomes most often involved were, by decreasing incidence, 5, 17, 8, 11, 7 and 21 in 57.9%, 55.3%, 44.7%, 36.8%, 34.2% and 34.2% of the cases, respectively. There were 98 unbalanced translocations, which were the most frequently observed aberrations in our study. Derivative chromosome 5 and 8 were implicated most often. The other derivatives were der(11), der(12), der(7), der(14), der(15) and der(17). Fourteen balanced translocations were detected in our series, and the most frequent reciprocal translocations was t(8;21). Fifty-five monosomies, 15 partial deletions, and 18 trisomies were found in all patients. The most frequently observed were ,5/5q,, ,17/17q,, ,7, ,18, ,21, ,19, and trisomy of chromosome 8 and 6. There were some abnormalities that have not been previously described, including two complex t(8;21) and seven unbalanced translocations. M-FISH could refine CCA, find or correct the missed or misidentified aberrations by CC analysis. Our findings confirmed that M-FISH was a powerful molecular cytogenetic tool to characterize complex karyotypes in MDS and AML. [source]

Allosyndetic recombinants of the Aegilops peregrina- derived Lr59 translocation in common wheat

PLANT BREEDING, Issue 4 2010
G. F. Marais
With 2 figures and 2 tables Abstract The wild relatives constitute a valuable source of rust resistance genes that can be utilized in wheat breeding. However, translocation of desirable genes through chromosome engineering inevitably results in co-transfer of deleterious wild species chromatin. An attempt was made to replace such redundant alien chromatin on the Lr59 translocation through homoeologous chromosome pairing and crossing over in the absence of Ph1. Strong segregation distortion resulted in the recovery of an unexpectedly high frequency of resistant recombinants. Eight of these retained comparatively short, distal segments of foreign chromatin, including Lr59. The foreign chromatin that remained in the latter plants was characterized with the use of twelve anonymous AFLP loci, the data of which suggested reduced homoeology with 1AL that could have been the result of a sub-terminal, paracentric inversion. Crossing over within an inversion loop may have resulted in a low frequency of genetically unbalanced gametes. It will therefore be necessary to develop near-isogenic lines of the eight recombinants and to do field evaluations in order to identify those that retained the shortest, balanced translocations. [source]

Analysis of two translocation breakpoints and identification of a negative regulatory element in patients with Rieger's syndrome

BIRTH DEFECTS RESEARCH, Issue 2 2004
Dimitri G. Trembath
Abstract BACKGROUND Rieger's syndrome is an autosomal dominant disorder characterized by eye, tooth, and umbilical anomalies. A gene responsible for Rieger's syndrome, PITX2, has previously been cloned using two patients with balanced translocations, t(4;16) and t(4;11), with breakpoints that lie near the gene, but which do not interrupt it. METHODS We sequenced both breakpoint regions on chromosome 4 and screened this area for novel genes. Fluorescence in situ hybridization (FISH) was used to determine if PITX2 was still present on the 4:16 chromosome. Both the chromosome 16 and chromosome 11 breakpoints were cloned and sequenced using panhandle polymerase chain reaction (PHPCR). Transient transfection studies were performed to compare effects on a reporter gene between native chromosome 4 sequence and chromosome 11 sequence. RESULTS The region surrounding PITX2 on chromosome 4 is rich in repetitive elements, but no novel genes were identified. FISH demonstrated that PITX2 was intact on the 4:16 translocation chromosome. The PHPCR experiments demonstrated that the translocated regions of chromosomes 16 and 11 were repeat-rich, and transfection studies revealed a slight enhancer effect with the chromosome 4 sequence, and a strong silencer effect when the chromosome 11 sequence was present. CONCLUSIONS Given the lack of any novel genes near either breakpoint, changes in potential regulatory elements may be the best model to explain the loss of PITX2 expression in these patients and hence the Rieger's syndrome phenotype. Birth Defects Research (Part A), 2004. © 2004 Wiley-Liss, Inc. [source]

Prospective application of a multiplex reverse transcription-polymerase chain reaction assay for the detection of balanced translocations in leukaemia: a single-laboratory study of 390 paediatric and adult patients

BRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2004
Lene Hyldahl Olesen
Summary The upfront application of molecular methods for identifying the fusion transcripts arising from balanced translocations in haematopoietic malignancies has several advantages: sensitivity is independent of its frequency, i.e. rare ones are not missed, cytogenetically cryptic aberrations are identified and it provides a platform for minimal residual disease (MRD) detection. Employing a multiplex reverse transcription polymerase chain reaction (RT-PCR) assay identifying 27 fusion transcripts we prospectively analysed blood and/or bone marrow samples from 390 patients referred for diagnosis and treatment for acute leukaemia and chronic myeloproliferative disorders (CMPD) from a geographically well-defined region in Denmark. A total of 233 patients were diagnosed with acute myeloid leukaemia (AML), 95 with acute lymphoblastic leukaemia (ALL) origin and 62 patients were recorded as CMPD. Twenty-three percent AML, 32% ALL and 55% CMPD patients exhibited chromosomal aberrations detected by the multiplex RT-PCR. Cytogenetically cryptic translocations were seen in 15% of the cases. Conversely, the cytogenetic analysis identified chromosomal aberrations other than translocations in 45% of AML cases and 63% of ALL cases. We conclude that, while the fraction of translocation positive leukaemia patients in an unselected cohort is lower than hitherto believed, a molecular approach to their diagnosis is worthwhile, partly for identifying cryptic and rare translocations, partly for monitoring MRD. [source]