Molecular genetic analyses in familial and sporadic congenital primary erythrocytosis.

Dominant mutations in the erythropoietin receptor (EPOR) gene account for only about 15% of cases of primary congenital erythrocytosis. To search for molecular alterations in patients with this disorder. Sixteen patients with Epo <10 mU/mL were studied, 3 were related. Analyses included EPOR and JAK2 gene sequencing, quantitative PRV-1 RT-PCR, and erythroid colony assays. A novel sporadic EPOR 1453G->A (Trp439Stop) mutation was detected. All familial cases, varied in phenotype, presented the EPOR 1414C->G (Tyr426Stop) mutation. JAK2 mutations are not involved in the pathogenesis of primary congenital erythrocytosis.