Integration of optical genome mapping in the cytogenomic and molecular work-up of hematological malignancies: expert recommendations from the International Consortium for Optical Genome Mapping

Abstract

The latest updates to the classification of hematolymphoid malignancies using the World Health Organization (WHO, 5th ed.) and ICC (International Consensus Classification) criteria highlight the critical need for comprehensive and precise cytogenomic data for diagnosis, prognostication, and treatment. This presents significant challenges for clinical laboratories, requiring a complex workflow using multiple assays to detect different types of structural chromosomal variants (copy number changes, fusions, inversions) across the entire genome. Optical genome mapping (OGM) is an advanced cytogenomic tool for genome-wide detection of structural chromosomal alterations at the gene/exon level. Studies demonstrate that OGM facilitates the identification of novel cytogenomic biomarkers, improves risk stratification, and expands therapeutic targets and personalized treatment strategies. OGM is easy to implement and highly accurate in detecting structural variants (SVs) across various diagnostic entities. Consequently, many centers are integrating OGM into the clinical cytogenetic workflow for hematological malignancies. However, systemic clinical adoption has remained limited due to the lack of expert recommendations on clinical indications, testing algorithms, and result interpretation. To address this, experts from the International Consortium for OGM and relevant multidisciplinary fields developed recommendations for the integration of OGM as a standard-of-care cytogenetic assay for the diagnostic workflow in various clinical settings. These recommendations standardize the use of OGM across laboratories, ensure high-quality cytogenetic data, guide clinical trial design and development, and provide a basis for updates to diagnostic and classification models.