Clinical Characteristic of "triple-negative" Essential Thrombocythaemia Patients and Mutation Analysis by Targeted Sequencing

Abstract

BACKGROUND: Essential thrombocythemia is a subgroup of myeloproliferative neoplasms. Previous studies identified mutations of JAK2, CALR, and MPL that are closely related with the pathogenesis of myeloproliferative neoplasms. All these mutations contribute to the hyperactivation of JAK2/STAT pathway. However, a small proportion of essential thrombocythemia patients does not display such mutations. The pathogenesis of "triple-negative" form of essential thrombocythemia remains unknown. OBJECTIVE: To investigate the clinical characteristics of triple-negative essential thrombocythemia and related mutation genes. METHODS: To identify the mutations associated with triple-negative essential thrombocythemia, next-generation sequencing was used to conduct targeted sequencing of 360 genes in samples from 68 patients. RESULTS: At least one missense mutation was detected in all the patients and all the detected genes. After screening the data, it was observed that 10 genes with the 10 highest mutation were follows: FLT3, SH2B3, ASXL1, ADAMTS1, TET2, TP53, EGFR, CUX1, GATA2, and MPL.When only rare genes (i.e., with a frequency in Asian populations lower than 5%, as estimated by the 1000 Genomes Project) were analyzed, the most frequently mutated genes in the patients were TET2 (33.82%), SH2B3(29.41%), and ASXL1 (23.53%). Our study identified some mutations that did not previously reported. Although all these mutations need further validation, high incidence rates may indicate relevance of the respective mutations to essential thrombocythemia pathogenesis. Some of the detected mutations have been previously reported; these mutations were also found in a large proportion of our subjects. CONCLUSION: whole-exon sequencing can provide a higher level of accuracy for gene mutation analysis and assist in identifying mutations that contribute to illustrate the pathogenesis of essential thrombocythemia.