Clinical and molecular characterisation of a prospectively collected cohort of children and adolescents with polycythemia vera.

The clinical, haematological, molecular and treatment data of eight paediatric patients with polycythemia vera (PV) were collected prospectively. One patient developed PV after treatment for large-cell anaplastic lymphoma. Budd-Chiari syndrome was diagnosed in two patients, necessitating orthotopic liver transplantation in one and transjugular portosystemic shunting in the other. The remaining patients presented with non-specific symptoms. Endogenous erythroid colonies were detected in all cases examined. The JAK2(V617F) mutation was found in six patients; two patients displayed JAK2 exon 12 mutations, including one novel mutation (JAK2(H538-K539delinsI)). CD177 (PRV-1) mRNA expression was increased in three of five patients tested.