At a center for hematological malignancy molecular diagnostics that receives greater than 2000 JAK2 V617F diagnostic tests per annum, from January 2006 to June 2022 inclusive, 73 requests for JAK2 V617F mutation status were identified with clinical details provided of OSA and either erythrocytosis and/or raised hemoglobin and/or raised hematocrit. Here, JAK2 is linked to polycythemia.