Polycythemia is a rare condition in which an increase in erythrocyte mass is observed. It can be primary or secondary. Primary polycythemia occurs as a result of congenital or acquired mutations that regulate erythroid development. Although secondary polycythemia is mostly seen secondary to hypoxia due to cardiac/pulmonary reasons, it also develops as a result of congenital mutations. Globin gene mutations that increase the affinity of hemoglobin for oxygen are one of these rare causes.

We present a male case who was referred to us for polycythemia.

A 15-year-old male patient with no known disease was referred to us after his school screening revealed high hemoglobin (18 g/dL). In complete blood count, other series were normal (wbc 5.8 × 103/µL neu 3.3 × 103/µL plt 174 × 103/µL), bilirubins and liver functions were within normal limits. On physical examination, conjunctiva and hands were pletoric, there was no hepatosplenomegaly, intermittent headaches were present, and neurological examination was normal. The patient was examined for the etiology of polycythemia. Hyperchromic erythrocytes were found in peripheral smear, no signs of hemolysis were observed. EPO level (8 mIU/ml) was in the normal range and JAK2 (V617F) mutation was negative. The patient's cardiac and pulmonary functions were within normal limits. Hemoglobin electrophoresis was sent from the patient. HbA was determined as 59.2, HbA2 2.8, Variant Hb 38. c.435G>T mutation was detected in the HBB genetic analysis, and this was considered to be compatible with Hemoglobin Andrew-Minneapolis. It was learned that the patient's mother and her cousins had similar findings, and some of them had undergone phlebotomy. Phlebotomy was planned in the presence of the patient's hemoglobin value > 18 g/dL and clinical findings. Phlebotomy was performed 3 times, aspirin was not started because there was no history of thromboembolism. In our 1-year follow-up, the hemoglobin value was 17-17.5 g/dL.

More than a hundred globin gene mutations associated with erythrocytosis have been described. Hemoglobin Andrew-Minneapolis mutation is one of them. Hemoglobin's affinity for oxygen has increased and EPO level is normal/increased. Due to the low number of cases, treatment recommendations were prepared based on polycythemia vera guidelines. Patients should be closely monitored in terms of hyperviscosity and thromboembolism, aspirin prophylaxis and phlebotomy are recommended according to symptoms. While investigating the etiology of polycythemia, hemoglobin electrophoresis is necessary, although it is very rare.