[Targeted sequencing analysis of hyper-eosinophilic syndrome and chronic eosinophilic leukemia]

Objective: Analysis of the molecular characteristics of eosinophilia. Methods: Targeting sequence to 24 patients with chronic eosinophilic leukemia (CEL) with rearrangement of PDGFRA, PDGFRB, or FGFR1 and 62 patients with hyper-eosinophilic syndrome (HES). Mutation annotation and analysis of amino acid mutation using authoritative databases to speculate on possible pathogenic mutation. Results: Thirty-seven kinds of clonal variant were detected from 17 patients with CEL, no recurrent mutation site and hot spot region were found. No pathogenic mutation was detected in 19 patients with PDGFRA rearrangement, but pathogenic mutations of ASXL1, RUNX1 and NRAS were detected from 2 patients with FGFR1 rearrangement who progressed to acute myeloid leukemia and 1 patient with PDGFRB rearrangement who progressed to T lymphoblastic lymphoma, respectively. One hundred and two kinds of clonal abnormalities were detected in 49 patients with HES. The main hot spot mutation regions included: CEBPA Exon1, TET2 Exon3, ASXL1 Exon12, IDH1 Y208C, and FGFR3 L164V. CRRLF2 P224L and PDGFRB R370C point mutations were detected separately in 2 patients with HES who treated with imatinib monotherapy and achieved hematologic remission. Conclusion: The pathogenesis of CEL with PDGFRA, PDGFRB or FGFR1 rearrangement is usually single, and the progression of the disease may involve other driver mutation. A variety of genes with hot mutation regions may be involved in the pathogenesis of HES, and some mutation sites are sensitive to tyrosine kinase inhibitors.