JAK2 mutational status and the contribution of TERT and JAK2 polymorphisms to the occurrence of myeloproliferative neoplasms in Eastern Morocco

Background: The JAK2 V617F somatic mutation is a hallmark of myeloproliferative neoplasms (MPN) and is present in some patients with splanchnic venous thrombosis (SVT). Objectives: We investigated for the first time in Eastern Morocco the JAK2 mutational status and germline risk factors, such as the TERT and JAK2 polymorphisms, in MPN and SVT patients. Methods: This study included 38 patients with MPN, 24 patients presenting with SVT and 60 healthy donors from the BRO Biobank. JAK2 mutations were analyzed using qPCR and Sanger sequencing. Predisposing polymorphisms to MPN were evaluated using Sanger sequencing. Results: JAK2 V617F mutation was positive in 64.5% of patients with MPN and 20.8% of patients with SVT. The JAK2 V617F allelic burden ranged from 2% to 97.53%. We found a strong association between the JAK2 rs56241661 polymorphism of the JAK2 46/1 haplotype and the development of MPN. However, no association was detected between the TERT rs2736100 polymorpism and MPN. Conclusion: The JAK2 mutational status and its allelic burden in Eastern Morocco are consistent with previous studies. The JAK2 46/1 haplotype was strongly associated with MPN. However, unlike other previously studied populations, the TERT polymorphism rs2736100 has no effect on the occurrence of MPN in our population. Keywords: Myeloproliferative neoplasms; JAK2 V617F; TERT and JAK2 polymorphisms; genetic predisposition; Morocco.