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Disease Profile

Primary familial and congenital polycythemia

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset

All ages





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Familial erythrocytosis; Primary congenital erythrocytosis; Familial erythrocytosis type 1;


Blood Diseases; Congenital and Genetic Diseases


Primary familial and congenital polycythemia (PFCP) is an inherited blood disease that causes uncontrolled production of red blood cells (erythrocytes). This leads to an increased volume of red blood cells compared to the total blood volume (erythrocytosis). It may also lead to increased total blood volume or increased blood thickness (hyperviscosity), both of which can cause symptoms. The disease is present at birth, but symptoms (if they develop) may arise any time during childhood or adulthood. Possible symptoms may include headaches, dizziness, fatigue, nosebleeds, difficulty breathing after physical activity, muscle pain, a reddish complexion, and altered mental status. Some people develop blood clots that can block various blood vessels, preventing adequate blood flow (thromboembolic events). Most people have mild symptoms, but some people experience life-threatening complications such as heart attack or stroke.[1][2] The risk of thrombosis and severe complications increases with age.[2]

PFCP is diagnosed by blood tests detecting isolated erythrocytosis and low EPO levels, in the absence of spleen abnormalities and other underlying diseases that can cause erythrocytosis (such as certain blood diseases and blood cancers).[1][2]

PFCP is inherited in an autosomal dominant manner, but some people with PFCP have no relatives with the disease. In about 12-15% of people with PFCP, it is caused by mutations in the EPOR gene. However in most people, the genetic cause is not yet known.[1][2][3]

Most people with PFCP do not need ongoing treatment. Some people with high blood volume need to have blood drawn periodically (phlebotomy) to treat symptoms or to maintain close-to-normal hematocrit levels. Some people with PFCP need medicines to lower blood pressure (antihypertensive therapy).[1]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Abnormal hemoglobin
Bloody nose
Frequent nosebleeds
Nose bleed
Nose bleeding

[ more ]


[ more ]

Increased red blood cells
Venous thrombosis
Blood clot in vein
Dizzy spell
30%-79% of people have these symptoms
Abdominal pain
Pain in stomach
Stomach pain

[ more ]

Joint pain
Itchy skin
Skin itching

[ more ]

5%-29% of people have these symptoms
Exertional dyspnea
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
Cerebral hemorrhage
Bleeding in brain
Increased hematocrit
Increased hemoglobin
Increased red blood cell mass
Myocardial infarction
Heart attack
Peripheral thrombosis
Peripheral blood clot
Increased spleen size


Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.


    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Social Networking Websites

        Learn more

        These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

        Where to Start

        • Genetics Home Reference (GHR) contains information on Primary familial and congenital polycythemia. This website is maintained by the National Library of Medicine.

          In-Depth Information

          • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
          • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
          • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
          • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
          • PubMed is a searchable database of medical literature and lists journal articles that discuss Primary familial and congenital polycythemia. Click on the link to view a sample search on this topic.


            1. Bento C, McMullin MF, Percy M, Cario H. Primary Familial and Congenital Polycythemia. GeneReviews. November 10, 2016; https://www.ncbi.nlm.nih.gov/books/NBK395975/.
            2. Briere J. Primary familial polycythemia. Orphanet. July, 2010; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=90042.
            3. Bocchini CA. Erythrocytosis, Familial, 1; ECYT1. Online Mendelian Inheritance in Man (OMIM). April 14, 2014; https://www.omim.org/entry/133100.