In vitro test for EEC
In vitro test for EEC, JAK2 mutations and paraclinical parameters were performed by routine analysis.
Discussion It is always important to make the correct diagnosis – in particular when molecular biological analyses are available. The pursuit of the correct diagnosis was intensified in these AL 8697 patients when signs of clonality were not demonstrated. Since there was a family history with erythrocytosis, and furthermore, because patient 2 was young to develop PV, other reasons for polycythaemia were considered. The inheritance in myeloproliferative disorders is complex and difficult to evaluate in a single family (Fig. 1) . Hereditary erythrocytosis can be associated with mutations in the gene encoding the erythropoietin receptor, defects in the oxygen sensing pathways and abnormal oxygen delivery . Calculation of P50 may be indicative of abnormal oxygen delivery in patients with erythrocytosis . If a low value is found the next step would be sequencing of the globin genes. In the patients reported here P50 was not calculated, specifically due to marcoumar anticoagulation therapy in patient 1. Alternatively, the specific diagnostic analyses were performed. A review of the literature and reported cases show cones erythrocytosis due to high oxygen affinity haemoglobin is usually well tolerated in younger patients, but in the elderly patients the risk of thrombosis is increased . The development of pulmonary embolism in patient 1 seems to be secondary to other causes. Treatment strategy in high affinity hemoglobinopathia should be decided individually [1,2].