The Comparison of GP1bα genotypes and alleles between patients with negative and positive JAK2 mutations patients in the studied groups showed that positive JAK2 mutation was of no significance difference in all genotypes and alleles in PV and ET patients (P > 0.05) while positive JAK2 mutation was significantly associated with TC and CC genotypes (P = 0.005), TC + CC (P = 0.004) and C allele (P = 0.001) these data were showed in Table 3. Here, JAK2 is linked to essential thrombocythemia.