24. Clinical utility of optical genome mapping: comparison with standard cytogenomics work-up for hematological malignancies

Gokce Toruner

Gokce Toruner, MD, PhD is a laboratory geneticist specialized in clinical cytogenetics and clinical molecular genetics. He is currently an associate professor in the Department of Hematopathology at the MD Anderson Cancer Center. Dr. Toruner received his medical degree from Hacettepe University, Turkey and earned his Ph.D. from Bilkent University, Turkey. Following his research post-doctoral training at the Rutgers-New Jersey Medical School, he completed a clinical laboratory fellowship in clinical molecular genomics and cytogenomics in the same institution. His clinical expertise is on cancer cytogenomics, NGS based solid tumor testing, and liquid biopsy. His current academic activities focus on structural and copy number aberration in neoplasia and incidental constitutional genetic findings detected during somatic genetic testing


Gokce Toruner, Zhenya Tang, Rashmi Kanagal-Shamanna, L. Jeffrey Medeiros, Guilin Tang

The University of Texas MD Anderson Cancer Center, Houston, TX, United States

Introduction: Cytogenetic testing provides important information for the diagnosis and management of patients with hematological malignancies. Standard cytogenomics work-up (SCW) includes G-banded karyotyping and fluorescence in situ hybridization. Optical genome mapping (OGM) is a novel and genomic DNA-based technology for cytogenomics testing. In this study, we assessed the clinical utility of OGM compared to SCW in our laboratory.

Methods: Between 10/1/2022 and 2/8/2023, OGM was performed on freshly collected blood/bone marrow specimens from 61 patients with hematological malignancies also assessed by SCW. The cohort included 25 acute myeloid leukemia, 4 with myelodysplastic syndrome (MDS), 4 with MDS/myeloproliferative neoplasm (MPN), 6 with MPN, 9 acute lymphoblastic leukemia (4 B, 5 T), 5 chronic lymphocytic leukemia, 5 mantle cell lymphoma and 3 T prolymphocytic leukemia. All patients had concurrent SCW. The clinical significance of OGM findings was determined based on the 2019 ACMG and CGC Consensus Recommendation.

Results: OGM detected additional aberrations with clinical significance in 21 of 61 (34%) patients that were not detected by concurrent SCW (due to cryptic on G-banded karyotyping or lack of metaphases resulting from poor growth of neoplastic cells). Examples of these aberrations include atypical MECOM rearrangements, BCR::JAK2, PML::SYK, cryptic EGR1 deletion, TRA::MTCP and TRA::GNAQ. In addition, OGM detected chromoanagenesis in 12 patients. These additional findings are important for disease diagnosis, risk-stratification and/or management.

Discussion: Compared with SCW, OGM provides clinically important additional results in approximately one third of patients. Integrating OGM with SCW can be beneficial for the management of patients with hematological malignancies.