What Causes Polycythemia Vera?
Polycythemia vera (PV) is also known as primary
polycythemia. It begins with a change to the DNA, a molecule present in every
living cell, which forms genes-the hereditary material of the cell. This change
is called a mutation. A mutation in the JAK 2 gene causes PV. The JAK 2 gene
produces an important protein involved in blood production. Doctors and
researchers do not know what causes the JAK 2 gene to change. The mutation of
the JAK 2 gene occurs after conception. It is not passed from parent to child.
The mutation of the JAK 2 gene cannot be reversed.
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. |