Highlights
l Essential thrombocythemia (ET) is one of a related
group of blood cancers known as “myeloproliferative
neoplasms” (MPNs) in which cells in the bone
marrow that produce the blood cells develop and
function abnormally.
l ET begins with one or more acquired changes
(mutations) to the DNA of a single blood-forming
cell. This results in the overproduction of blood cells,
especially platelets, in the bone marrow.
l About half of individuals with ET have a mutation
of the JAK2 (Janus kinase 2) gene. The role that this
mutation plays in the development of the disease,
and the potential implications for new treatments,
are being investigated.
l Individuals with ET may not have symptoms.
Patients with signs or symptoms may have burning
or throbbing pain in the feet or hands, headaches,
dizziness, blood clots or abnormal bleeding episodes.
l ET does not generally shorten life expectancy. Still,
medical supervision of individuals with ET is
important to prevent or treat complications.