Clinical Impact of Next‐Generation Sequencing–Detected Mutations on Thrombotic Events in Myeloproliferative Neoplasms

ABSTRACT Introduction Myeloproliferative neoplasms (MPNs), encompassing polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are hematologic malignancies characterized by recurrent somatic mutations. Despite advances in next‐generation sequencing (NGS), the genetic basis of thrombotic risk and bone marrow (BM) fibrosis in MPNs remains unclear. Methods Patients diagnosed with classical MPN at Trakya University Faculty of Medicine were retrospectively analyzed (2018–2025). Mutation profiling was conducted on BM aspirates using a 78‐gene panel on the Illumina NextSeq platform, with clinically relevant variants (VAF ≥ 2%) interpreted via Qiagen Clinical Insight. Results Among 91 patients with MPN, the most frequent mutations were JAK2 (71.4%), TET2 (23.1%), DNMT3A (15.4%), ASXL1 (11%), and splicing factor mutations (SFMs; 12%). Arterial events occurred in 45.1% of patients and were associated with age ( p < 0.001), higher Charlson Comorbidity Index (CCI; p < 0.001), ASXL1 (p:0.019), and SFMs (p:0.009). VTE occurred in 38.5% and was associated with JAK2 status and allele burden (p:0.004 and p:0.012 respectively), TET2 ( p < 0.001), and SFMs (p:0.002); the JAK2/TET2 co‐mutant subgroup had the highest risk of VTE risk in multivariable analysis (OR: 2.9, 95% CI: 1.4–5.7; p:0.002). Advanced BM fibrosis was associated with SFMs (p:0.018). Increased mutational burden correlated with both venous and arterial thrombosis (p:0.021 and p:0.044, respectively). In survival analyses, SFMs (HR: 5.2; p:0.008), ASXL1 (HR: 3.8; p:0.030), and PMF diagnosis (HR: 3.8; p:0.045) were associated with inferior overall survival (OS). Conclusion Molecular profiling may provide clinically relevant thrombotic risk stratification in classical MPNs. JAK2/TET2 co‐mutation was linked to VTE, while ASXL1 and SFMs were associated with adverse phenotypes including vascular events, BM fibrosis, and inferior OS.