Polymorphism of the tumour necrosis factor-alpha and lymphotoxin-alpha genes in hairy cell leukaemia

Erythrocytosis arises from a variety of pathogenic mechanisms. We sequenced a 256-bp region 3' to the erythropoietin (Epo) gene which included a 24- to 50-bp minimal hypoxia-responsive element spanning HIF-1- and HNF-4-binding sites in 12 patients with erythrocytosis and 4 normal subjects. Four polymorphisms were found, none of which affected the HIF-1-binding site, although one polymorphism was present in the HNF-4 consensus region. The data indicate that none of these polymorphisms cause erythrocytosis.