Research: JAK2 in trouble again

New mutations with diagnostic potential have been discovered in people with a type of myeloproliferative disorder.

Myeloproliferative disorders are a group of conditions in which an excess of blood cells – red or white cells or platelets – are made in the bone marrow. The diseases are slow-acting and people can often live for many years after diagnosis, but the complications can be serious. A single mutation in a gene called JAK2, which helps the cell respond to growth factors, was recently found in many individuals with a type of myeloproliferative disorder. The mutation leaves the JAK2 protein continuously in an 'on' state.

An international team led by Tony Green at the University of Cambridge has now discovered several new mutations in a completely different region of JAK2. The new mutations also leave the protein in an unregulated state. People with these novel mutations appear to represent a previously unrecognised subtype of myeloproliferative disorder with distinct clinical and laboratory features.

The discovery of JAK2 mutations has already altered the way that myeloproliferative disorders are classified and diagnosed. Researchers now hope it will be possible to develop JAK2 inhibitors as a novel approach to therapy.

External links

• Scott LM et al. JAK2 exon 12 mutations in polycythemia vera and idiopathic erythrocytosis. N Engl J Med 2007;356(5):459–68.