Polycythemia Vera (PV) is a rare, chronic disorder involving the overproduction of blood cells in the bone marrow (myeloproliferation). This overproduction (hyperplasia) of blood cells results in the thickening of the blood (hyperviscosity), leading to symptoms such as dizziness, itchiness (pruritus), and a feeling of fullness in the stomach (satiety). PV primarily affects middle-aged to elderly individuals (age 50-75) and is slightly more common in men than in women.
Polycythemia Vera is generally classified as a type of myeloproliferative neoplasm and is not typically divided into subtypes. However, the disease can manifest in different ways and progress at different rates in different individuals. Some people with PV may experience severe symptoms and complications, while others may have few, if any, symptoms and complications. The disease can also transform into more serious conditions, such as myelofibrosis or acute leukemia, in some cases.
Why do people get Polycythemia Vera?
The exact cause of Polycythemia Vera is unknown. However, most people with PV have a mutation in the JAK2 gene. This gene makes a protein that helps the body produce blood cells. A mutation in the JAK2 gene results in the production of too many blood cells, leading to PV. It's not clear what causes this mutation and it's generally not inherited. Instead, it's acquired, or happens sometime during a person's life. Other risk factors for PV include: being male, being of Jewish descent, and being over 60 years of age.
Who gets Polycythemia Vera?
An estimated number of people in a population with a diagnosis of PV is approximately 22 cases per 100,000 people. It can usually be managed effectively for a long time. Each patient’s risk factors, which affect his or her prognosis, are evaluated individually. In people with PV, median survival approaches or exceeds 20 years. Some people may survive longer after diagnosis, perhaps achieving a near-normal life expectancy.