Polycythemia vera is not hereditary. While it results from a genetic mutation, or a change in the DNA in a bone marrow cell, the change usually develops during life. It isn’t something you are born with or inherit.

Instead, it results from acquired mutations in specific genes and DNA sequences, usually with Janus kinase-2 (JAK2) signaling. The JAK2 gene makes a protein that promotes cell growth and division. Polycythemia vera results in increased red blood cell production, or erythrocytosis.

Having too many red blood cells can increase the risk of blood clots and other health conditions, such as stroke and heart attack.

While polycythemia vera is not hereditary, a rare form of erythrocytosis can run in families. It is known as primary familial and congenital erythrocytosis (PFCE) and was formerly known as primary familial and congenital polycythemia (PFCP). It has been reported to affect about 125 people from more than 20 families.

Polycythemia vera results from a mutation in a bone marrow stem cell, but researchers haven’t yet determined the underlying cause of that mutation.

While it’s possible that the cell changes may have outside triggers, like similar blood disorders, the cause of polycythemia vera is still unknown.

It’s also possible that the changes may happen in a cell without a particular outside trigger.

Polycythemia vera tends to develop in people over age 60.

PFCE results from mutations in the erythropoietin (EPO) receptor, a part of the bone marrow that helps make red blood cells.

PFCE is hereditary. It is inherited in an autosomal dominant inheritance pattern. Autosomal means that the gene is present on the chromosomes a person receives from each parent. A dominant inheritance pattern means that only one copy of the gene is required to cause the PFCE.

That means if a person has it, their offspring have a 50% chance of receiving the chromosome containing the gene.

If someone in your family has received a diagnosis of polycythemia vera or another similar blood disorder, genetic testing can reveal if PFCE may be a factor.

Polycythemia vera can be managed with treatment like a chronic condition.

Treatment may involve:

  • removing excess blood from your body in a process similar to a blood donation (phlebotomy)
  • taking medications or following certain practices to prevent blood clots
  • medications for other complications and symptoms, such as itching
  • bone marrow transplant for advanced polycythemia vera
  • regular monitoring of your blood cell counts and side effects