Correlation of Genomic Characteristic with Disease Progression in Polycythemia Vera

ZHAO Yingxu; BAI Jie; ZHANG Lei; SHENG Mengyao; SHI Hui; XING Wen; YANG Fengchun; AI Limei; ZHOU Yuan

doi:10.3969/j.issn.0253-9896.2014.06.002

Abstract：Objective To screen mutations in genes including ASXL1, TET2, IDH1, IDH2, SETBP1, MPL515, JAK2 exon 12 and JAK2V617 in 135 polycythemia vera (PV) patients. To assess progreasson and genomics characteristics post polycythemic myelofibrosis. Methods DNA sequencing of ASXL1(Exon12),TET2 (Exons 3-11),IDH1(Exon4),IDH2(Ex-on4),SEPBP1(Exon4),JAK2 exon 12 and MPL515 (Exon 10) genes were carried out using Sanger method. JAK2V617 muta-tion was detected by allele-specific PCR in patients with PV. In the mean time, the mutation load of JAK2V617F allele (V617F%) was evaluated by real-time PCR using Tagman MGB probe. Then, the significant of gene mutations and clinical outcomes of post-PV Myelofibrosis(PPMF)was analyzed. To study risk factors of PPMF, logistic regression were employed. Results ASXL1, TET2, IDH1, IDH2 were mutated in 7.69%(8/104), 5.26%(1/19) , 0.08%(1/120) and 0.08%(1/121) of all PV patient respectively. JAK2 was mutated in 82.22%(111/135) of PV patients with mutation rate of exon12 of 2.96%(4/135) and there were no mutation of MPL515 and SETBP1 in PV patients. ASXL1 mutation was found in 31.82%(7/22) PPMF patients. Spearman analysis showed that ASXL1 is correlated with JAK2V617F (V617F%) (rs=0.298,P=0.002). The hemo-globin was lower in patients with ASXL1 mutation than patient without mutation (wild type). Leukocyte count, V617F%>50%rate, thrombosis and PPMF were higher in patients with ASXL1 mutation than that of ASXL1 wild type(P<0.05). ASXL1 mu-tation, V617F%>50% rate and splenomegaly were all risk factors of PPMF. Conclusion ASXL1 mutation is the risk-fac-tor of PPMF and may promote V617F%by some mechanism.