JAK2 and hypercalcemia disease: Of 20,086 and 9,570 diagnostic requests for the JAK2 V617F mutation and BCR-ABL1 fusion respectively, 59 requests (0.2 %) were received for investigation of either JAK2 V617F (n=35), BCR-ABL1 (n=12) or both (n=12), with the sole clinical details provided of hypercalcemia.