TO THE EDITOR: Recent advancements in next-generation sequencing (NGS) technologies have enabled comprehensive genomic characterization of hematological malignancies. This has led to the discovery of numerous biomarkers, transforming the diagnosis, risk stratification, and personalized therapeutic intervention for these diseases. With the clinical significance of molecular testing, an increasing number of laboratories offer NGS analysis for hematological malignancies. Although various in-house and commercial panels are available, the target of genomic regions and genes of each panel are different. Therefore, I want to suggest several clinically relevant core genes for hematologic malignancies panels focusing on DNA testing, and, it will be helpful when employing clinically applicable NGS panel testing for hematologic malignancies.

According to the recently released 5th edition of the World Health Organization Classification of haematolymphoid tumours: myeloid and histiocytic/dendritic neoplasms [1], the myeloid malignancies panel should target genes of newly defined entities: NPM1 and CEBPA, and molecular alterations defining “AML, myelodysplasia-related”, such as ASXL1, BCOR, EZH2, RUNX1, SF3B1, SRSF2, STAG2, U2AF1, and ZRSR2 for acute myeloid leukemia. Newly defined entities for myelodysplastic neoplasms (MDS), SF3B1 and TP53, and the diagnostic criteria for BCR-ABL1- negative myeloproliferative neoplasms (MPN), JAK2, CALR, MPL, CSF3R, and KIT, should also be targeted.

With respect to prognosis, the recently released Molecular International Prognostic Scoring System for myelodysplastic syndromes (IPSS-M) [2] offers a curated list of 31 genes that merit prioritization. Also, certain genes are known to correlate with poor prognosis in BCR::ABL1-negative MPN. Moreover, the myeloid malignancy panel requires testing for therapeutic markers, such as FLT3 mutations (including FLT3-ITD) and IDH1/2 mutations to select targeted drugs for acute myeloid leukemia (AML), and ABL1 mutations to assess the response to tyrosine kinase inhibitor drugs for chronic myeloid leukemia (CML) [3].

In addition to, the 5th edition of the WHO classification of hematolymphoid tumors recognizes subtypes of myeloid neoplasms associated with germline predisposition to myeloid and histiocytic/dendritic neoplasms [1], and genes for these subtypes should be included in the panel. A comprehensive summary of the genes related to myeloid malignancies and their clinical significance is presented in Table 1.

In the recently released 5th edition of the World Health Organization classification of hematolymphoid tumors: lymphoid neoplasms [4], the category denoted as BCR::ABL1- like features have gained acknowledgment for their diverse array of genetic abnormalities, including JAK-STAT alterations, ABL1 class fusions, and various other mutations. Mutations in SH2B3, IL7R, and JAK1/2/3 have been linked to JAK-STAT alteration [5]. Moreover, the ICC 2022 classification introduced two distinctive entities characterized by hotspot point mutations: IKZF1 N159Y and PAX5 P80R [6]. In T-cell lymphoblastic leukemia (T-ALL), NOTCH1 activating mutations and CDKN2A/B deletions represented pivotal pathogenic genes, collectively detected in 50–60% of cases, and approximately 30% of T-ALL cases exhibiting NOTCH1 mutations were concomitant with FBXW7 missense mutations [7]. In contrast to T-ALL, early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) were manifested with distinctive genetic anomalies that distinguished it from conventional T-ALL. ETP-ALL lacked the common alterations observed in T-ALL, including NOTCH1 mutations and CDKN2A/B deletions. ETP-ALL was presented with a high incidence of mutations typically associated with acute myeloid leukemia (AML) [8].

In terms of prognosis, certain genes, including TP53 and those associated with chromatin modification such as CREBBP and SETD2, had demonstrated a correlation with an unfavorable prognosis in B-ALL. Moreover, copy number deletions of IKZF1 have been linked to poorer outcomes; in particular, the IKZF1 plus condition, characterized by the deletion of IKZF1 along with co-occurring deletions in CDKN2A, CDKN2B, PAX5, or PAR1 in the absence of ERG deletion, was associated with worse prognostic outcomes, especially in pediatric patients with B-ALL [9]. Moreover, both B-ALL cases exhibiting BCR::ABL1-like features and those characterized as early

Similar to CML, it is essential to test for ABL1 mutations and the PDGFRB C843G mutation, as they confer resistance to the tyrosine kinase inhibitors (TKIs) frequently used in the treatment of individuals with Philadelphia chromosome-positive ALL (ph+-ALL) [12]. Moreover, CREBBP mutations have been identified as contributors to glucocorticoid resistance in B-cell precursor acute lymphoblastic leukemia [9]. It is also crucial to consider the impact of germline variants in drug-metabolizing enzyme genes, specifically TPMT and NUDT15, and on the risk of thiopurine toxicity, which is integral to the successful treatment of ALL [13]. These insights underscore the significance of genetic testing in developing therapeutic strategies and predicting treatment responses in patients with ALL. A comprehensive summary of the genes related to ALL and their clinical significance is provided in Table 2.

The genetic landscape of lymphoma and chronic lymphocytic leukemia (CLL) presents substantial complexity and diversity in most cases. Recent years have witnessed a rapid accumulation of knowledge, revealing a growing catalogue of recurrently mutated genes and their consequential clinical implications, which have been facilitated by advancements in next-generation sequencing technologies. Certain gene mutations within this spectrum have a significant influence on the diagnostic, prognostic, and therapeutic aspects of lymphoid neoplasms. Furthermore, recent multiplatform genomic studies have shed light on genetic subtypes and distinctive genetic features of Diffuse Large B-cell Lymphoma (DLBCL) [14]. These findings improve our understanding of the genetic underpinnings of DLBCL, which is a critical advancement in this field. The genes associated with lymphoma and chronic lymphocytic leukemia, along with their clinical significance encompassing diagnostic, prognostic, and therapeutic impacts, are compiled and presented in Table 3 [3, 7, 14-20] with corresponding references.

The evolution of diagnostic methodologies, risk stratification guidelines, and targeted therapies for hematologic malignancies underscores the escalating significance of thoroughly assessing an extensive array of genetic biomarkers when making informed decisions about front-line patient care. Next-generation sequencing (NGS) has emerged as a valuable tool for the prompt delivery of results across a wide spectrum of genetic targets. Moreover, the expeditious establishment of an NGS test system and its streamlined integration into clinical processes should be considered for efficient patient care.