Project description:Large but not small copy-number alterations correlate to high-risk genomic aberrations and survival in chronic lymphocytic leukemia: a high-resolution genomic screening of newly diagnosed patients. Single nucleotide polymorphism (SNP)-arrays allow simultaneous detection of copy-number aberrations (CNAs) and copy-number neutral loss-of-heterozygosity (CNN-LOH). In this study we investigated the presence of CNAs and CNN-LOH in newly diagnosed CLL samples from a Swedish chronic lymphocytic leukemia (CLL) cohort. In this study we could detect the known recurrent aberrations in CLL (i.e. deletions of 13q, 11q, 17p and trisomy 12). We also detected other both large and small CNAs which were mostly non-recurrent. CNN-LOH was detected on chromosome 13q in patients that carried homozygous deletion of 13q.
Project description:Genomic aberrations are of predominant importance to the biology and clinical outcome of patients with chronic lymphocytic leukemia (CLL), and FISH-based genomic risk classifications are routinely used in clinical decision making in CLL. One of the known limitations of CLL FISH is the inability to comprehensively interrogate the CLL genome for genomic changes. In an effort at overcoming the existing limitations in CLL genome analysis, we have analyzed high-purity DNA isolated from FACS-sorted CD19+ cells and paired CD3+ or buccal cells from 255 CLL patients for acquired genomic copy number aberrations (aCNA) using ultra-high-density Affymetrix SNP 6.0 arrays. Overall, two or more subchromosomal aCNA were found in 39% (100/255) of all cases analyzed, while ≥3 subchromosomal aCNA were detected in 20% (50/255) of cases. Subsequently, we have correlated genomic lesion loads (genomic complexity) with the clinical outcome measures time to first therapy (TTFT) and overall survival (OS). Using multivariate analyses incorporating the most important prognostic factors in CLL together with SNP 6.0 array-based genomic lesion loads at various thresholds, we identify elevated CLL genomic complexity as an independent and powerful marker for the identification of CLL patients with aggressive disease and short survival. we have analyzed high-purity DNA isolated from FACS-sorted CD19+ cells and paired CD3+ or buccal cells from 255 CLL patients for acquired genomic copy number aberrations (aCNA) using ultra-high-density Affymetrix SNP 6.0 arrays
Project description:High-resolution genomic microarrays provides simultaneous detection of copy-number aberrations such as the known recurrent aberrations in Chronic Lymphocytic Leukemia_diagnostic sample_patient (del(11q), del(13q), del(17p) and trisomy 12), and copy-number neutral loss of heterozygosity. We screened 369 newly diagnosed Chronic Lymphocytic Leukemia_diagnostic sample_patient patient samples from a population-based cohort using 250K single nucleotide polymorphism-arrays.
Project description:High-resolution genomic microarrays provides simultaneous detection of copy-number aberrations such as the known recurrent aberrations in Chronic Lymphocytic Leukemia_diagnostic sample_patient (del(11q), del(13q), del(17p) and trisomy 12), and copy-number neutral loss of heterozygosity. We screened 369 newly diagnosed Chronic Lymphocytic Leukemia_diagnostic sample_patient patient samples from a population-based cohort using 250K single nucleotide polymorphism-arrays. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from peripheral blood samples.
Project description:Genomic aberrations are of predominant importance to the biology and clinical outcome of patients with chronic lymphocytic leukemia (CLL), and FISH-based genomic risk classifications are routinely used in clinical decision making in CLL. One of the known limitations of CLL FISH is the inability to comprehensively interrogate the CLL genome for genomic changes. In an effort at overcoming the existing limitations in CLL genome analysis, we have analyzed high-purity DNA isolated from FACS-sorted CD19+ cells and paired CD3+ or buccal cells from 255 CLL patients for acquired genomic copy number aberrations (aCNA) using ultra-high-density Affymetrix SNP 6.0 arrays. Overall, two or more subchromosomal aCNA were found in 39% (100/255) of all cases analyzed, while ≥3 subchromosomal aCNA were detected in 20% (50/255) of cases. Subsequently, we have correlated genomic lesion loads (genomic complexity) with the clinical outcome measures time to first therapy (TTFT) and overall survival (OS). Using multivariate analyses incorporating the most important prognostic factors in CLL together with SNP 6.0 array-based genomic lesion loads at various thresholds, we identify elevated CLL genomic complexity as an independent and powerful marker for the identification of CLL patients with aggressive disease and short survival.
Project description:Genomic profiles of CLL (Chronic Lymphocytic Leukemia) patients. 11 CLL patients were selected for detection of genomic aberrations, 8 patients with atypical CLL and 3 patients with typical CLL.
Project description:Screening for gene copy-number alterations (CNAs) has improved by applying genome-wide microarrays, where SNP arrays also allow analysis of loss of heterozygozity (LOH). We here analyzed 10 chronic lymphocytic leukemia (CLL) samples using four different high-resolution platforms: BAC arrays (32K), oligonucleotide arrays (185K, Agilent), and two SNP arrays (250K, Affymetrix and 317K, Illumina). Cross-platform comparison revealed 29 concordantly detected CNAs, including known recurrent alterations, which confirmed that all platforms are powerful tools when screening for large aberrations. However, detection of 32 additional regions present in 2-3 platforms illustrated a discrepancy in detection of small CNAs, which often involved reported copy-number variations. LOH analysis revealed concordance of mainly large regions, but showed numerous, small nonoverlapping regions and LOH escaping detection. Evaluation of baseline variation and copy-number ratio response showed the best performance for the Agilent platform and confirmed the robustness of BAC arrays. Accordingly, these platforms demonstrated a higher degree of platform-specific CNAs. The SNP arrays displayed higher technical variation, although this was compensated by high density of elements. Affymetrix detected a higher degree of CNAs compared to Illumina, while the latter showed a lower noise level and higher detection rate in the LOH analysis. Large-scale studies of genomic aberrations are now feasible, but new tools for LOH analysis are requested. 10 chronic lymphocytic leukemia (CLL) samples was analyzed using four different high-resolution platforms: 32K BAC arrays, 185K Agilent oligonucleotide arrays, 250K Affymetrix SNP arrays and 317K Illumina SNP arrays.
Project description:Chronic lymphocytic leukemia (CLL) is the most frequent leukemia in Western countries. The main genetic alterations associated to this disease are loss of 13q14, loss of 11q23, trisomy 12 and, less frequently, 17p13 losses, and are routinely studied using fluorescence in situ hybridization. These genomic aberrations have been demonstrated to be important independent predictors of disease progression in CLL and their detection currently has a direct implication in the treatment strategy of the patients. It has been widely demonstrated that array-based karyotyping clearly detects DNA gains and losses and allows the identification of CLL abnormalities not included in the standard FISH panel. We have here established and tested an oligonucleotide-based array platform for the diagnosis of CLL that interrogates the most relevant chromosomal regions related with the disease and may help in the differential diagnosis between CLL and other small B-cell leukemias and may be used as a powerful prognosis tool to stratify the CLL patients. Copy number analysis using Custom Agilent 60K was performed on 47 chronic lymphocytic Leukemia patients with sex-matched control DNAs