VEGFA rs3025020 Polymorphism Contributes to CALR -Mutation Susceptibility and Is Associated with Low Risk of Deep Vein Thrombosis in Primary Myelofibrosis.

Background  Single nucleotide polymorphisms (SNPs) in vascular endothelial growth factor A ( VEGFA ) are associated with susceptibility to several diseases including cancer. Correlations between VEGFA rs3025020 genotypes with clinical and laboratory features of primary myelofibrosis (PMF) are unstudied. Methods  DNA was analyzed by real-time polymerase chain reaction for VEGFA rs3025020 genotypes in a cohort of 844 subjects with PMF and in two cohorts of normal subjects ( N  = 247 and N  = 107). Results  Frequency of rs3025020 minor allele (T) was not significantly different in subjects with PMF compared with normals; however, the T-allele was more frequent in PMF subjects with a calreticulin ( CALR )-mutated genotype compared with normals (35 vs. 27%; OR = 1.47 [95% CI, 1.09, 1.98] p  = 0.011), especially in subjects with a CALR- type 2/type 2-like mutation (43 vs. 27%; OR = 2.01 [1.25, 3.24] p  = 0.004). CALR mutants with the rs3025020 TT genotype had higher CXCR4 expression on CD34-positive blood cells, and those who carried CT/TT genotypes had lower platelet concentrations compared with other genotypes at diagnosis. Overall, subjects with the rs3025020 CT/TT genotype had a lower cumulative incidence of deep vein thrombosis in typical sites (1.6 vs. 4.2%; OR = 0.37 [0.15, 0.90] p  = 0.029) and longer interval from diagnosis to first thrombosis (HR = 0.37 [0.14, 0.95] p  = 0.039). Conclusion  Persons with PMF and the VEGFA rs3025020 minor T-allele are more likely to have a CALR mutation compared with other somatic driver mutations and lower cumulative incidence and hazard for deep vein thrombosis in typical sites.