Familial Essential Thrombocythemia Associated with MPL W515L Mutation in Father and JAK2 V617F Mutation in Daughter

TET2 rs1548483 SNP Associating with Susceptibility to Molecularly Annotated Polycythemia Vera and Primary Myelofibrosis

Background: The complexity of myeloproliferative neoplasms (MPNs) cannot be characterized by acquired somatic mutations alone. Individual genetic background is thought to contribute to the development of MPNs. The aim of our study was to assess the association between the TET2 rs1548483 single nucleotide polymorphism (SNP) and the susceptibility to polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF) or chronic myeloid leukemia (CML). Methods: We evaluated the TET2 rs1548483 SNP through real-time PCR in 1601 MPN patients out of which 431 with PV, 688 with TE, 233 with PMF, 249 with CML and 197 controls. We included only patients with a molecularly proven driver mutation, such as JAK2 V617F, CALR or BCR-ABL1. Results: Significant association between TET2 rs154843 variant allele and JAK2 V617F-positive PV and PMF (OR = 1.70; 95% CI: 1.01–2.91; p-value = 0.046, and OR = 2.04; 95% CI: 1.10–3.77; p-value = 0.024, respectively), and type 2 CALR-positive PMF (OR = 2.98; 95% CI: 1.12–7.93; p-value = 0.035) was noted. Conclusions: The TET2 rs1548483 SNP is associated with the susceptibility to molecularly annotated PV and PMF.

SH2B3 (LNK) rs3184504 polymorphism is correlated with JAK2 V617F-positive myeloproliferative neoplasms

Background: Pathogenesis and phenotypic diversity in myeloproliferative neoplasms (MPN) cannot be fully explained by the currently known acquired mutations alone. Some susceptible germline variants of different genes have been proved to be associated with the development of these diseases. The goal of our study was to evaluate the association between the rs3184504 polymorphism of SH2B3 (LNK) gene (p.R262W, c.784T>C) and the risk of developing the four typical MPN - polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF), and chronic myeloid leukemia (CML).

Material and methods: We investigated the SH2B3 rs3184504 T>C polymorphism by real-time PCR in 1901 MPN patients (575 with PV, 798 with ET, 251 with PMF, and 277 with CML), all of them harboring one of the specific driver mutations - JAK2 V617F or CALR in case of PV, ET and PMF, or BCR-ABL1 in case of CML, and 359 controls.

Results: Overall, the TT homozygous genotype was significantly associated with BCR-ABL1-negative MPN (OR = 1.34; 95% CI = 1.03-1.74; crude p-value = 0.02; adjusted p-value = 0.04). The most significant association was seen in case of PV (OR = 1.54; 95% CI = 1.14-2.06; crude p-value = 0.004; adjusted p-value = 0.024). Also, SH2B3 rs3184504 correlated significantly with JAK2 V617F-positive MPN (OR = 1.36; 95% CI = 1.04-1.77; crude p-value = 0.02; adjusted p-value = 0.08), but not with those CALR-positive. ET (regardless of molecular subtype) and CML were not correlated with SH2B3 rs3184504.

Conclusions: The SH2B3 rs3184504 polymorphism is associated with risk of MPN development, especially PV. This effect is restricted to JAK2 V617F-positive PV and PMF only.

TERT rs2736100 A>C SNP and JAK2 46/1 haplotype significantly contribute to the occurrence of JAK2 V617F and CALR mutated myeloproliferative neoplasms - a multicentric study on 529 patients

Polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF) represent typical myeloproliferative neoplasms (MPN), usually characterized by specific somatic driver mutations (JAK2 V617F, CALR and MPL). JAK2 46/1 haplotype and telomerase reverse transcriptase gene (TERT) rs2736100 A>C single nucleotide polymorphism (SNP) could represent a large fraction of the genetic predisposition seen in MPN. The rs10974944 C>G SNP, tagging the JAK2 46/1 haplotype, and the TERT rs2736100 A>C SNP were genotyped in 529 MPN patients with known JAK2 V617F, CALR and MPL status, and 433 controls. JAK2 46/1 haplotype strongly correlated to JAK2 V617F-positive MPN and, to a lesser extent, CALR-positive MPN. The TERT rs2736100 A>C SNP strongly correlated to all MPN, regardless of the phenotype (PV, ET or PMF) and major molecular subtype (JAK2 V617F- or CALR-positive). While both variants have a significant contribution, they have nuanced consequences, with JAK2 46/1 predisposing essentially to JAK2 V617F-positive MPN, and TERT rs2736100 A>C having a more general, non-specific effect on all MPN, regardless of phenotype or major molecular subtype.