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Disease Profile

Familial isolated hyperparathyroidism

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






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)

Hyperparathyroidism 1; HRPT1; Hyperparathyroidism, familial isolated primary;


Familial isolated hyperparathyroidism (FIHP) is an inherited form of primary hyperparathyroidism that is not associated with other features.[1] The age of diagnosis varies from childhood to adulthood. In FIHP, tumors involving the parathyroid glands cause the production and release of excess parathyroid hormone, which in turn causes increased calcium in the blood (hypercalcemia). The tumors are usually benign, but a cancerous tumor can develop in rare cases. Abnormal levels of calcium cause many of the symptoms of FIHP, including kidney stones, nausea, vomiting, high blood pressure (hypertension), weakness, and fatigue. Osteoporosis often also develops. FIHP may be caused by mutations in the MEN1, CDC73 (also known as the HRPT2 gene), or CASR genes and is typically inherited in an autosomal dominant manner. In some cases, the cause is unknown. Mutations in the MEN1 and CDC73 genes cause other conditions in which hyperparathyroidism is one of many features, but some people with mutations in these genes have only isolated hyperparathyroidism. FIHP can also represent an early stage of other syndromes.[2] Treatment for FIHP often includes surgical removal of the affected gland(s).[3]


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:
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
High blood calcium levels
Increased calcium in blood

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Primary hyperparathyroidism


The diagnosis of familial isolated hyperparathyroidism (FIHP) is primarily a diagnosis of exclusion. This means that it is diagnosed when no symptoms or genetic features of other forms of familial hyperparathyroidism are present. FIHP may be the only feature of another condition that is not manifesting completely, or it may be a distinct condition due to mutations in genes that have not yet been identified. Clinical exams, laboratory tests, and histological (microscopic) findings are needed before making a diagnosis of FIHP.[4]

A diagnosis of FIHP may include the findings of:

In the majority of people with FIHP, genetic mutations are not found. However, in some people, mutations in
the MEN1, CASR, and CDC73 (HRPT2) genes have been reported. At this time, no gene has been associated exclusively with FIHP.[4]


FDA-Approved Treatments

The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.

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

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.
  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • 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 Familial isolated hyperparathyroidism. Click on the link to view a sample search on this topic.


  1. Thereasa A Rich, Mimi I Hu, Jack W Martin, Nancy D Perrier, and Steven G Waguespack. CDC73-Related Disorders. GeneReviews. May 24, 2012; https://www.ncbi.nlm.nih.gov/books/NBK3789/. Accessed 12/22/2014.
  2. Familial isolated hyperparathyroidism. Genetics Home Reference. August, 2012; https://ghr.nlm.nih.gov/condition/familial-isolated-hyperparathyroidism. Accessed 12/22/2014.
  3. Lawrence Kim. Hyperparathyroidism. Medscape. April 28, 2014; https://emedicine.medscape.com/article/127351-overview#aw2aab6b4. Accessed 12/22/2014.
  4. Pontikides N, et. al. Genetic basis of familial isolated hyperparathyroidism: a case series and a narrative review of the literature. J Bone Miner Metab. July 2014; 32(4):351-366.

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