What Causes Polycythemia Vera?
Polycythemia vera (PV) also is known as primary
polycythemia. A mutation, or change, in the body's JAK 2 gene causes PV. The
JAK 2 gene makes an important protein that helps the body produce blood cells.
What causes the change in the JAK 2 gene isn't known. PV isn't passed from
parent to child. However, in some families, there may be a tendency for the JAK
2 gene to mutate.
There is another kind of polycythemia not related to
the JAK 2 gene. This is called secondary polycythemia. The cause of secondary
polycythemia is known. It is caused by long-term exposure to low levels of
oxygen. Long-term lack of oxygen can cause your body to produce more of the
hormone erythropoietin (EPO). EPO increases the production of red blood cells
above normal levels, leading to thickening of the blood as in PV. People who
smoke, spend long hours at high altitudes (such as mountaineers and pilots), or
have severe lung or heart disease may develop secondary polycythemia. In some
cases, secondary polycythemia can be cured, depending on whether the underlying
cause can be controlled or cured. |