Heterogeneous group of primary polycythemias. Secondary polycythemias are due to an increased secretion of erythropoietin either in response to hypoxemia, either from a tumoral origin (paraneoplastic syndrome).

A distinction is made between:

-        ECYT1 [MIM 133 100]: autosomal dominant transmission of a mutation of the EPOR gene (19p13.2) resulting in hypersensitivity of the erythropoietin gene with isolated erythrocytosis without risk of leukemia. A somatic mutation of the JAK2 (9p24.1) or QH2B3 (12q24.12) genes can produce the same clinical presentation.

-        ECYT2 [MIM 263 400]: autosomal recessive transmission of a mutation of the VHL gene (3p25) producing Chuvash erythrocytosis (Russia); erythropoietin levels are high; other mutations of the same gene produce von Hippel-Lindau syndrome

-        ECYT3 [MIM 609 820]: autosomal dominant transmission of a mutation of the EGLN1 gene (1q42);

-        ECYT4 [MIM 611 783]: autosomal dominant transmission of a mutation of the EPAS1 gene (2p21); it is sometimes associated with paragangliomas (see Pacak-Zhuang syndrome )

-        ECYT5 [MIM 617 907]: autosomal dominant transmission of a mutation of the EPO gene (7q22)

-        ECYT6 [MIM 617 980]: autosomal dominant transmission of a mutation of the HBB gene (11q5) leading to an increased affinity of the hemoglobin globin β for oxygen

-        ECYT7 [MIM 617 981]: autosomal dominant transmission of a mutation of the HBA1 or HBA2 gene (16p13) resulting in an increased affinity of hemoglobin globin α for oxygen

-        ECYT8 [MIM 222 800]: autosomal recessive transmission of a mutation of the BPGM gene (7q33) resulting in decreased in intra-erythrocytic levels of 2,3-diphosphoglycerate mutase; it is sometimes associated with haemolytic anemia

Anesthetic implications: 

check hemoglobin level and total blood count; increased thromboembolic risk

References : 

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Updated: April 2022