JAK2 mutations in Asian patients with essential thrombocythaemia

Background/Aim: JAK2V617F is an acquired mutation present in a considerable proportion of patients with chronic myeloproliferative disorders. Its reported prevalence in European and US studies of patients with essential thrombocythaemia (ET) is 23-57%. This study was conducted to determine the prevalence of the JAK2 mutation in Asian ET patients, and to examine their disease profile. Methods: Asian patients with ET were either recruited to the study or registry data were analysed retrospectively. Blood samples were collected for analysis of JAK2 mutation status during routine patient follow up. Clinical data on these patients (including demographics and disease profiles) and complications at diagnosis were recorded. Results: The JAK2 mutation was detected in 35/102 (34%) patients. Females were more likely than males to have JAK2 mutation (P = 0.031). At diagnosis, JAK2-mutated patients were found to be older (P = 0.012), have higher leucocyte counts (P = 0.036) and high-risk disease (P = 0.039). There were no other statistically significant differences between mutated and wild-type JAK2 ET patients. Conclusion: The prevalence of JAK2 mutations in this population of Asian ET patients was 34%. Patients with the JAK2 mutation were significantly more likely to have high-risk disease. Further studies are required to assess the role of JAK2 mutations in risk stratification in ET and compare the phenotype of Asian patients with other populations.