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Updated: May 27, 2026
Chromosome Preparation From Cultured Cells
Published on: January 28, 2014
DNA copy number changes and immunophenotype pattern in karyotypically normal acute myeloid leukemia patients from an
Nikesh Kawankar1, Seema Korgaonkar, Lily Kerketta
1Department of Cytogenetics, National Institute of Immunohaematology (NIIH), Parel, Mumbai, India. vbaburao@hotmail.com
Insights
This study found hidden DNA copy number variations in normal karyotype acute myeloid leukemia (AML) patients. These genetic changes correlate with aberrant immunophenotypes and impact disease prognosis.
Area of Science:
- Hematology
- Genetics
- Oncology
Background:
- Chromosomal abnormalities are critical for acute myeloid leukemia (AML) diagnosis and prognosis.
- Karyotypically normal AML presents a diagnostic challenge, as standard cytogenetics may miss crucial genetic alterations.
Purpose of the Study:
- To identify DNA copy number variations (CNVs) in karyotypically normal AML patients.
- To investigate the correlation between these CNVs and patient immunophenotypes.
Main Methods:
- Comparative genomic hybridization (CGH) was used to detect CNVs.
- Immunophenotyping was performed on 46 untreated AML patients.
- Patients with abnormal karyotypes were excluded, focusing on those with normal cytogenetics.
Main Results:
- Out of 46 karyotypically normal AML patients, 24 (52.2%) exhibited DNA copy number variations (CNVs).
- CNVs included both gains and losses across various chromosomes.
- Aberrant immunophenotypes were observed in 13 of the 24 patients with CNVs (54%).
Conclusions:
- CGH identified "hidden" chromosomal rearrangements missed by conventional cytogenetics and FISH in normal karyotype AML.
- Detected genetic changes are significant for disease prognosis.
- CNVs may contribute to aberrant immunophenotypes in this AML subgroup.
Abstract:
Chromosomal abnormalities are important in the diagnosis and prognosis of patients with acute myeloid leukemia (AML). The purpose of this study was to identify DNA copy number variations in karyotypically normal AML patients and their correlation with immunophenotypes. Conventional comparative genomic hybridization (CGH) and immunophenotyping were performed in 46 untreated AML patients aged 7-68 years. Among the 86 Indian patients who had AML, 40 (46.5%) showed an abnormal karyotype and 46 (53.4%) showed no chromosome aberrations. The karyotypically abnormal AML patients were excluded from the study. Out of the 46 patients without chromosomal aberrations, 24 (52.2%) showed DNA copy number variations including losses and gains. The DNA copy number variations involved chromosomes 1, 3, 6, 12, 15, 16, 17 (gains) and 1, 4, 2, 3, 5, 7, 8, 9, 10, 11, 13, 15, 18, 20, 21 (losses). The aberrant immunophenotype was noticed in 13 of these 24 (54%) cases. The hidden chromosome rearrangements in karyotypically normal AML, which could not be detected by conventional cytogenetics and fluorescence in situ hybridization, were detected by CGH. These genetic changes have an important role in the prognosis of the disease. The DNA copy number changes might also be involved in the aberrant immunophenotypes in our study.
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