JAK2 p.(V617F) mutation in Tunisian myeloproliferative neoplasms and its genotype-phenotype correlation

Abstract

Myeloproliferative neoplasms (MPNs) comprise polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The relationship between JAK2 p.(V617F) mutation and MPNs was first described in 2005. The purpose of this study was to determine the prevalence of JAK2 p.(V617F) mutation in Tunisian patients assessed for MPNs and try to set a genotype-phenotype correlation. A retrospective study was conducted between January 2015 and April 2019. We collected the clinical data of all patients with MPNs suspicion or atypical splanchnic vein thrombosis (SVT). JAK2 p.(V617F) mutation was detected by allele specific real-time quantitative fluorescence PCR (AS-qPCR). We gathered 974 patients who underwent molecular analysis, 55.5% of them were male and 44.5% were female. The median age of all studied patients was 56 years. JAK2 p.(V617F) was found in 349 (35.8%) of total enrolled cases. It was reported in 44%, 37%, 29% and 25% of all patients diagnosed as having respectively ET, PV, PMF and atypical SVT. JAK2 p.(V617F) was negative in 62.2% of patients addressed for suspicion of PV. There was a significant positive correlation between the JAK2 p.(V617F) mutation status, age, gender, white blood cell counts and platelet counts. To our best knowledge, this is the first vast investigation of JAK2 p.(V617F) variant in Tunisia and North Africa with the lowest mutation rate in entire cohort and MPNs subgroups, underlying a specific presentation of this mutation. It is considered as an essential marker of MPNs' diagnosis and prognosis and is associated with differences in the phenotype of these disorders, helpful for the follow-up of these patients.

Keywords: JAK2 p.(V617F); Myeloproliferative neoplasms; essential thrombocythemia; polycythemia vera; primary myelofibrosis.

Figure 1

age distribution in wild type and mutant JAK2 subgroups (ET: essential thrombocythemia; MPNs: myeloproliferative neoplasms; PMF: Primary myelofibrosis; PV: polycythemia vera; WT: wildtype)

Figure 2

sex-specific differences in Tunisian cohort and wild type or mutant JAK2 subgroups (ET: essential thrombocythemia; PMF: primary myelofibrosis; PV: polycythemia vera)