Mutations in Triple-Negative Patients with Myeloproliferative Neoplasms

Background Myeloproliferative neoplasms (MPNs) are chronic hematopoietic stem cell disorders, including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (MF). JAK2, MPL, and CALR mutations are considered as “driver mutations” and are directly implicated in the disease pathogenesis by activation of JAK/STAT signaling. However, some patients do not harbor any of these mutations. Since such triple-negative MPNs are very rare, no specific molecular markers were established to use for a precise differential diagnosis yet. So far, the introduction of next generation sequencing (NGS) technologies in research of myeloid neoplasms has provided valuable contributions on the identification of new molecular biomarkers, establishing more accurate risk rating and selection of more specific therapeutic interventions. This study aimed to identify, through targeted deep sequencing, specific genetic variants in patients with triple-negative MPNs. Methods We performed NGS targeted sequencing in 18 Brazilian triple-negative patients (11 MF and 7 ET). The median age at diagnosis was 64 years for primary myelofibrosis (range 42-78), and 52 years for essential thrombocythemia (range 19-79). In 14 cases, we used the Illumina TruSight Myeloid Panel covering 54 genes and in 4 cases we used a custom Sure Select Agilent panel containing more than 300 genes previously reported to be related to myeloid neoplasm. The inclusion criteria for variant filtering was quality score>30, read count>50, minor allele frequency