Project description:Copy number and LOH analysis was performed for 304 casesof B-progenitor and T-lineage acute lymphoblastic leukemia. All caseswere genotyped with Affymetrix 250k Sty and Nsp arrays. 252 cases werealso genotyped with Hind and Xba arrays. Keywords: Acute leukemia, BCR-ABL1, copy number analysis, loss-of-heterozygosity, genomics *** Due to privacy concerns, the primary SNP array data is no longer available with unrestricted access. Individuals wishing to obtain this data for research purposes may request access using the Web links below. ***
Project description:This SuperSeries is composed of the following subset Series: GSE28460: Expression data from ALL diagnosis and relapse pediatric acute lymphoblastic leukemia cases GSE28461: Promoter methylation data from ALL diagnosis and relapse pediatric acute lymphoblastic leukemia cases Refer to individual Series
Project description:We present here a genome-wide map of abnormalities found in diagnostic samples from 45 adults and adolescents with acute lymphoblastic leukemia (ALL). 500K single nucleotide polymorphism (SNP) array analysis uncovered frequent genetic abnormalities, with cryptic deletions constituting half of the detected changes, implying that microdeletions are a characteristic feature of this malignancy. Importantly, the pattern of deletions resembled that recently reported in pediatric ALL, suggesting that adult, adolescent, and childhood cases may be more similar on the genetic level than previously thought. Thus, 70% of the cases displayed deletion of one or more of the CDKN2A, PAX5, IKZF1, ETV6, RB1, and EBF1 genes. Furthermore, several genes not previously implicated in the pathogenesis of ALL were identified as possible recurrent targets of deletion. In total, the SNP array analysis identified 367 genetic abnormalities not corresponding to known copy number polymorphisms, with all but two cases (96%) displaying at least one cryptic change. This SNP array study is the first to specifically address adult and adolescent ALL, and the resolution level is the highest used to date to investigate a malignant hematologic disorder. Our findings provide insights into the leukemogenic process and may be clinically important in adult and adolescent ALL. Most importantly, we report that microdeletions of key genes appear to be a common, characteristic feature of ALL that is shared between different clinical, morphological, and cytogenetic subgroups. Keywords: Genomic analysis of acute lymphoblastic leukemia samples
Project description:This SuperSeries is composed of the following subset Series: GSE25102: Illumina SNP-array data for 2 ETV6/RUNX1-positive Acute Lymphoblastic Leukemia samples and corresponding normal samples GSE25116: Affymetrix SNP-array data for 2 ETV6/RUNX1-positive Acute Lymphoblastic Leukemia samples and corresponding normal samples Refer to individual Series
Project description:BCR-ABL1 lymphoblastic leukaemia is characterized by the deletion of Ikaros. The Philadelphia chromosome, encoding BCR-ABL1, is the defining lesion of chronic myelogenous leukemia (CML) and a subset of acute lymphoblastic leukemia (ALL) cases. To define oncogenic lesions that cooperate with BCR-ABL1 to induce ALL, we performed genome-wide analysis of leukemic samples from 23 CML cases and 304 ALL cases, including 43 BCR-ABL1 B-ALL cases. IKZF1 (encoding the transcription factor Ikaros) was deleted in 83.7% of BCR-ABL1 B-ALL cases, but not in chronic phase CML. Deletion of IKZF1 was also identified as an acquired lesion in lymphoid blast crisis of CML. The IKZF1 deletions resulted in haploinsufficiency, expression of a dominant negative Ikaros isoform or the complete loss of Ikaros expression. Sequencing of IKZF1 deletion breakpoints suggested that aberrant V(D)J recombination is responsible for the deletions. These findings suggest that genetic lesions resulting in the loss of Ikaros function are a key event in the development of BCR-ABL1 ALL. *** Due to privacy concerns, the primary SNP array data is no longer available with unrestricted access. Individuals wishing to obtain this data for research purposes may request access using the Web links below. *** This SuperSeries is composed of the SubSeries listed below.