ABSTRACT
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.
Subject(s)
Calreticulin/genetics , Haplotypes/genetics , Janus Kinase 2/genetics , Myeloproliferative Disorders/genetics , Telomerase/genetics , Adult , Aged , Case-Control Studies , Female , Genetic Predisposition to Disease , Humans , Male , Middle Aged , Mutation , Phenotype , Polycythemia Vera/genetics , Polymorphism, Single Nucleotide , Primary Myelofibrosis/genetics , Thrombocythemia, Essential/genetics , Young AdultABSTRACT
OBJECTIVES: To analyze the relationship between six polymorphisms in genes related to oxidative stress, namely CAT-262 C>T, MnSOD Ala16Val, GPX1 Pro198Leu, GSTM1 and GSTT1 null genotypes, and GSTP1 Ile105Val, and the occurrence of BCR-ABL negative myeloproliferative neoplasms (polycythemia vera, essential thrombocythemia, and primary myelofibrosis). METHODS: We genotyped for these polymorphisms 328 patients with a known mutation status for JAK2 V617F, MPL and CALR, and 363 controls, using molecular genetics assays. RESULTS: The CAT-262 C>T and GPX1 Pro198Leu polymorphisms were seen significantly less frequently, while the GSTP1 IleVal105 polymorphism was seen significantly more frequently in patients with BCR-ABL negative myeloproliferative neoplasms, regardless of the molecular sub-type (e.g. JAK2 V617F or CALR mutated). DISCUSSION AND CONCLUSION: Our study provides evidence that variation in genes related to oxidative stress might modulate the risk of developing BCR-ABL negative myeloproliferative neoplasms.
Subject(s)
Fusion Proteins, bcr-abl/genetics , Myeloproliferative Disorders/genetics , Oxidative Stress/genetics , Adult , Aged , Aged, 80 and over , Catalase/genetics , Female , Genes, abl , Genotype , Glutathione Peroxidase/genetics , Glutathione S-Transferase pi/genetics , Glutathione Transferase/genetics , Humans , Male , Middle Aged , Myeloproliferative Disorders/enzymology , Myeloproliferative Disorders/metabolism , Polymorphism, Single Nucleotide , Superoxide Dismutase/genetics , Glutathione Peroxidase GPX1ABSTRACT
The 2016 WHO-CMP classification proposal defines a broad spectrum of JAK2 V617F mutated MPN phenotypes: normocellular ET, hypercellular ET due to increased erythropoiesis (prodromal PV), hypercellular ET with megakaryocytic-granulocytic myeloproliferation and splenomegaly (EMGM or masked PV), erythrocythemic PV, early and overt classical PV, advanced PV with MF and post-PV MF. ET heterozygous for the JAK2 V617F mutation is associated with low JAK2 mutation load and normal life expectance. PV patients are hetero-homozygous versus homozygous for the JAK2 V617F mutation in their early versus advanced stages with increasing JAK2 mutation load from less than 50% to 100% and increase of MPN disease burden during life long follow-up in terms of symptomatic splenomegaly, constitutional symptoms, bone marrow hypercellularity and secondary MF. Pretreatment bone marrow biopsy in prefibrotic MPNs is of diagnostic and prognostic importance. JAK2 exon 12 mutated MPN is a distinct benign early stage PV. CALR mutated hypercellular thrombocythemia show distinct PMGM bone marrow characteristics of clustered larged immature dysmorphic megakaryocytes with bulky (bulbous) hyperchromatic nuclei, which are not seen in JAK2 mutated ET and PV. MPL mutated normocellular thrombocythemia is featured by clustered giant megakaryocytes with hyperlobulated stag-horn-like nuclei without features of PV in blood and bone marrow. Myeloproliferative disease burden in each of the JAK2, CALR and MPL MPNs is best reflected by the degree of anemia, splenomegaly, mutation allele burden, bone marrow cellularity and myelofibrosis.
