[Fundamentals of genetic counseling in hematology: pedigree construction and management of secondary findings in HemeSight®].

Abstract

Since the clinical adoption of comprehensive genomic profiling for hematologic malignancies (HemeSight^®) in 2025, hematologists have increasingly encountered germline findings in routine practice. In hematologic malignancies, genetic information is relevant not only to diagnosis, prognosis, and treatment selection, but also to the clinical management of at-risk relatives-including predictive testing- and donor selection for hematopoietic stem cell transplantation. This review summarizes the fundamentals of genetic counseling in hematology, focusing on the characteristics of genetic information, the distinction and relationship between genetic medicine and genetic counseling, the significance of family history-taking and pedigree construction, and the management of secondary findings identified through HemeSight^®. In addition, two hypothetical cases are presented: a case of AML with a pathogenic germline DDX41 variant and a case of pediatric ALL in which a pathogenic germline BRCA1 variant was identified as a secondary finding. These cases highlight practical issues, including predictive testing for relatives, evaluation of related donor candidates, and the need for multidisciplinary collaboration. In hematology practice, timely collaboration with clinical genetics services is essential for supporting patients and their families.