[Clinical and genetic characteristics of young patients with myeloproliferative neoplasms].

To investigate the clinical and genetic features of young Chinese patients with myeloproliferative neoplasms (MPN). In this cross-sectional study, anonymous questionnaires were distributed to patients with MPN patients nationwide. The respondents were divided into 3 groups based on their age at diagnosis: young (≤40 years) , middle-aged (41-60 years) , and elderly (>60 years) . We compared the clinical and genetic characteristics of three groups of MPN patients. 1727 assessable questionnaires were collected. There were 453 (26.2%) young respondents with MPNs, including 274 with essential thrombocythemia (ET) , 80 with polycythemia vera (PV) , and 99 with myelofibrosis. Among the young group, 178 (39.3%) were male, and the median age was 31 (18-40) years. In comparison to middle-aged and elderly respondents, young respondents with MPN were more likely to present with a higher proportion of unmarried status (all <0.001) , a higher education level (all <0.001) , less comorbidity (ies) , fewer medications (all <0.001) , and low-risk stratification (all <0.001) . Younger respondents experienced headache (ET, <0.001; PV, =0.007; MF, =0.001) at diagnosis, had splenomegaly at diagnosis (PV, <0.001) , and survey (ET, =0.052; PV, =0.063) . Younger respondents had fewer thrombotic events at diagnosis (ET, <0.001; PV, =0.011) and during the survey (ET, <0.001; PV, =0.003) . JAK2 mutations were found in fewer young people (ET, <0.001; PV, <0.001; MF, =0.013) ; however, CALR mutations were found in more young people (ET, <0.001; MF, =0.015) . Furthermore, mutations in non-driver genes (ET, =0.042; PV, =0.043; MF, =0.004) and high-molecular risk mutations (ET, =0.024; PV, =0.023; MF, =0.001) were found in fewer young respondents. Compared with middle-aged and elderly patients, young patients with MPN had unique clinical and genetic characteristics.