I had to go find out what Polycythemia vera is.

Quote:
Polycythemia vera is an acquired disorder of the bone marrow that causes the overproduction of all three blood cell lines: white blood cells, red blood cells, and platelets.

It is a rare disease that occurs more frequently in men than women, and rarely in patients under 40 years old. It is not known what causes polycythemia vera.

The disease usually develops slowly, and most patients do not experience any problems related to the disease after being diagnosed.
We will certainly keep your daughter in our thoughts and prayers and hope that she falls into the group that doesn't have problems. Hopefully with the early diagnosis and medication she will keep it under control.