Secondary Complex Chromosome Rearrangement Identified by Chromosome Analysis and FISH Subsequent to Detection of an Unbalanced Derivative Chromosome 12 by SNP Array Analysis

2013 ◽  
Vol 142 (2) ◽  
pp. 129-133 ◽  
Author(s):  
R.D. Burnside ◽  
L. Spudich ◽  
B. Rush ◽  
S. Kubendran ◽  
G.B. Schaefer
Keyword(s):  
Chromosome Rearrangement ◽  
Snp Array ◽  
Chromosome Analysis ◽  
Chromosome 12 ◽  
Derivative Chromosome ◽  
Array Analysis ◽  
Complex Chromosome Rearrangement ◽  
Snp Array Analysis ◽  
Complex Chromosome

scholarly journals Characterization of a Rare Mosaic Unbalanced Translocation of t(3;12) in a Patient With Neurodevelopmental Disorders

2021 ◽  
Author(s):  
Xiaolin Hu ◽  
Elizabeth K Baker ◽  
Jodie Johnson ◽  
Stephanie Balow ◽  
Loren D.M. Pena ◽  
...  
Keyword(s):  
De Novo ◽  
Chromosomal Abnormalities ◽  
Snp Array ◽  
Chromosome Analysis ◽  
Chromosome 12 ◽  
Derivative Chromosome ◽  
Unbalanced Translocation ◽  
Balanced Translocation ◽  
Chromosomal Disorders ◽  
History Of

Abstract Background Unbalanced translocations may be de novo or inherited from one parent carrying the balanced form and are usually present in all cells. Mosaic unbalanced translocations are extremely rare with a highly variable phenotype depending on the tissue distribution and level of mosaicism. Mosaicism for structural chromosomal abnormalities is clinically challenging for diagnosis and counseling due to the limitation of technical platforms and complex mechanisms, respectively. Here we report a case with a tremendously rare maternally-derived mosaic unbalanced translocation of t(3;12), and we illustrate the unreported complicated mechanism using single nucleotide polymorphism (SNP) array, fluorescence in situ hybridization (FISH), and chromosome analyses. Case Presentation: An 18-year-old female with a history of microcephaly, pervasive developmental disorder, intellectual disability, sensory integration disorder, gastroparesis, and hypotonia presented to our genetics clinic. She had negative karyotype by parental report but no other genetic testing performed previously. SNP microarray analysis revealed a complex genotype including 8.4 Mb terminal mosaic duplication on chromosome 3 (3p26.3->3p26.1) with the distal 5.7 Mb involving two parental haplotypes and the proximal 2.7 Mb involving three parental haplotypes, and a 6.1 Mb terminal mosaic deletion on chromosome 12 (12p13.33->12p13.31) with no evidence for a second haplotype. Adjacent to the mosaic deletion is an interstitial mosaic copy-neutral region of homozygosity (1.9 Mb, 12p13.31). The mother of this individual was confirmed by chromosome analysis and FISH that she carries a balanced translocation, t(3;12)(p26.1;p13.31). Conclusion Taken together, the proband, when at the stage of a zygote, likely carried the derivative chromosome 12 from this translocation, and a postzygotic mitotic recombination event occurred between the normal paternal chromosome 12 and maternal derivative chromosome 12 to “correct” the partial 3p trisomy and partial deletion of 12p. To the best of our knowledge, it is the first time that a mechanism utilizing a combined cytogenetic and cytogenomic approach, and we believe it expands our knowledge of mosaic structural chromosomal disorders and provides new insight into clinical management and genetic counseling.

scholarly journals CBFA2T3-GLIS2 Fusion Gene Cause Dismal Clinical Course in Acute Megakaryocytic Leukemia of Down Syndrome

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5184-5184
Author(s):  
Nao Takasugi ◽  
Kenichi Amano ◽  
Yasuo Kubota ◽  
Shota Kato ◽  
Yuichi Mitani ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Mutational Analysis ◽  
Clinical Course ◽  
Fusion Gene ◽  
Snp Array ◽  
Genomic Analysis ◽  
Array Analysis ◽  
Snp Array Analysis ◽  
Acute Megakaryocytic Leukemia ◽  
Gata1 Mutation

[Introduction] Acute megakaryocytic leukemia of Down syndrome (DS-AMKL) is characterized by excellent outcome with chemotherapy in contrast to non-Down syndrome-related AMKL (non-DS-AMKL). DS-AMKL and non-DS-AMKL have distinct genetic features which may underlie their different clinical characteristics. DS-AMKL is initiated by a GATA1 mutation in the transient abnormal myelopoiesis (TAM) phase and developed with further mutations of other regulators, while non-DS-AMKL is a heterogeneous group which occasionally carry chimeric oncogenes. CBFA2T3-GLIS2 fusion gene is identified in about 30% of children with non-DS-AMKL, and reported as a strong poor prognostic factor in pediatric AMKL. However, CBFA2T3-GLIS2 has never been reported in DS-AMKL and adult AMKL patients. We performed genomic analysis of DS-AMKL including atypical case with difficult clinical course. This is the first report of DS-AMKL harboring the CBFA2T3-GLIS2 fusion gene. [Case] The patient is a 1-year-old female of DS-AMKL with no prior episode of TAM. G-banding analysis revealed the karyotype both of the leukemic cells and normal tissue sample; 47, XX, +21. Chimeric genes of AML1-MTG8, CBFB-MYH, DEK-CAN, MLL-LTG4, MLL-LTG9, MLL-ENL and abnormalities of KIT and FLT3 were not detected. The chemotherapy according to the Japanese Pediatric Leukemia / Lymphoma Study Group AML-D05 protocol, gemtuzumab ozogamicin, IDA-FLAG regimen (idarubicin, fludarabine, cytarabine, filgrastim) and clofarabine-based regimen were tried, but all of them failed to achieve complete remission (CR). She underwent umbilical cord blood transplantation and relapsed on day 35 after transplantation. Once she showed a response to azacitidine, but finally she died on day 293 after transplantation. [Materials and Methods] We performed whole transcriptome sequencing (RNAseq), SNP array analysis, mutational analysis of GATA1 in 6 DS-AMKL samples, which included this refractory sample and five DS-AMKL samples with GATA1 mutations. To analyze gene expression profiling, we applied the hierarchical clustering method and principal component analysis. [Results] RNA sequencing analysis identified a fusion gene involving exon 10 of CBFA2T3 and exon 2 of GLIS2 gene in this refractory sample. This fusion gene was a result of a cryptic inversion on chromosome 16 and the in-frame fusion of both genes. The fusion transcript was validated by reverse transcription-polymerase chain reaction (RT-PCR) followed by Sanger sequencing. Though SNP array analysis confirmed 21 trisomy, it did not identify other copy number aberrations. PCR analysis did not detect GATA1 mutation in this refractory sample, which can be identified in other DS-AMKL samples. Expression analysis elucidated DS-AMKL with CBFA2T3-GLIS2 fusion had distinct expression profile from DS-AMKL with GATA1 mutations. [Discussion] CBFA2T3-GLIS2 fusion is the most common chimeric oncogene identified in non-DS-AMKL children, but has never been detected in DS-AMKL patients. Patients with non-DS-AMKL, especially holding CBFA2T3-GLIS2 fusion gene, have poorer outcomes than DS-AMKL. DS-AMKL patients generally have GATA1 mutations, show high sensitivity to chemotherapy, and can be treated with less intensive chemotherapy. However, our case had no GATA1 mutation and could not achieve CR despite intensive chemotherapy and transplantation. Thus, it is suggested this fusion gene caused the resistance to chemotherapies including hematopoietic stem cell transplantation in our case. Therefore, our case suggests patients with DS-AMKL should be surveyed genomic investigations including RNAseq and mutational analysis of GATA1 to identify their molecular biological subtypes before treatments are initiated. In case that fusion genes are detected in DS-AMKL patients, they must undergo highly intense chemotherapies, looking ahead to transplantation from the beginning of the treatment. Moreover, in case of harboring CBFA2T3-GLIS2 fusion gene, some potential therapies have been proposed, so that efficacy of such new therapies should be validated in a cell line-derived xenograft or patient-derived xenograft model. [Conclusion] DS-AMKL is generally known to show superior outcome, but DS-AMKL without GATA1 mutation and with CBFA2T3-GLIS2 fusion gene shows resistance to chemotherapies. For DS-AMKL patients, it is desirable to perform genomic analysis including RNAseq before chemotherapy. Disclosures No relevant conflicts of interest to declare.

Primary amenorrhea in a woman with a cryptic complex chromosome rearrangement involving the critical regions Xp11.2 and Xq24

2004 ◽  
Vol 82 (6) ◽  
pp. 1666-1671 ◽  
Author(s):  
Cristina Hernando ◽  
Alberto Plaja ◽  
Vicens Català ◽  
Enric Sarret ◽  
Josep Egozcue ◽  
...  
Keyword(s):  
Chromosome Rearrangement ◽  
Primary Amenorrhea ◽  
Complex Chromosome Rearrangement ◽  
Critical Regions ◽  
Complex Chromosome

scholarly journals SNP Array Analysis Reveals Novel Genomic Abnormalities Including Copy Neutral Loss of Heterozygosity in Anaplastic Oligodendrogliomas

PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e45950 ◽  
Author(s):  
Ahmed Idbaih ◽  
François Ducray ◽  
Caroline Dehais ◽  
Célia Courdy ◽  
Catherine Carpentier ◽  
...  
Keyword(s):  
Loss Of Heterozygosity ◽  
Neutral Loss ◽  
Snp Array ◽  
Array Analysis ◽  
Snp Array Analysis

scholarly journals A novel phenotype of 13q12.3 microdeletion characterized by epilepsy in an Asian child: a case report

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Mina Wang ◽  
Bin Li ◽  
Zehuan Liao ◽  
Yu Jia ◽  
Yuanbo Fu
Keyword(s):  
De Novo ◽  
Snp Array ◽  
Epileptic Seizures ◽  
Slow Waves ◽  
Recessive Mutation ◽  
Array Analysis ◽  
Single Nucleotide ◽  
Case Presentation ◽  
Snp Array Analysis ◽  
Cytogenetic Band

Abstract Background The microdeletion of chromosome 13 has been rarely reported. Here, we report a 14-year old Asian female with a de novo microdeletion on 13q12.3. Case presentation The child suffered mainly from two types of epileptic seizures: partial onset seizures and myoclonic seizures, accompanied with intellectual disability, developmental delay and minor dysmorphic features. The electroencephalogram disclosed slow waves in bilateral temporal, together with generalized spike-and-slow waves, multiple-spike-and-slow waves and slow waves in bilateral occipitotemporal regions. The exome sequencing showed no pathogenic genetic variation in the patient’s DNA sample. While the single nucleotide polymorphism (SNP) array analysis revealed a de novo microdeletion spanning 2.324 Mb, within the cytogenetic band 13q12.3. Conclusions The epilepsy may be associated with the mutation of KATNAL1 gene or the deletion unmasking a recessive mutation on the other allele, and our findings could provide a phenotypic expansion.

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