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Disease Profile

Familial isolated hypoparathyroidism

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.

<1 / 1 000 000

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



Eye diseases


The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Orpha Number: 2238

Familial isolated hypoparathyroidism (FIH) is a rare heterogeneous group of metabolic disorders characterized by abnormal calcium metabolism due to deficient secretion of parathormone (PTH), without other endocrine disorders or developmental defects.

Clinical description
It can occur at any age (from the newborn period to adulthood) but generally starts within the first decade of life. Diagnosis is made when hypocalcemia, hyperphosphoremia, and low or undetectable PTH levels are observed. The clinical signs are mainly those of hypocalcemia: myopathy, muscular weakness, cramps, tetany, lenticular cataracts, teeth anomalies and short stature.

FIH may be due to an activating mutation of the calcium-sensing receptor (CASR) gene. This is the most common cause of genetic hypoparathyroidism and is transmitted as an autosomal dominant trait. It represents 42% of isolated hypoparathyroidism cases. Thirteen mutations have been described in familial or sporadic cases. In three families, mutations in the PTH gene have been identified. This type of FIH is transmitted as an autosomal recessive or dominant trait. One family has been reported with a mutation in the gene encoding the glial cells missing homolog b (GCMB) transcription factor. In this case, transmission is autosomal recessive.

Genetic counseling
Isolated hypoparathyroidism may be sporadic or familial, with autosomal dominant or recessive inheritance.

Management and treatment
Management consists of symptomatic treatment with supplementary calcium and vitamin D.

Visit the Orphanet disease page for more resources.


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 calcium-phosphate regulating hormone level
Low blood calcium levels
Decreased parathyroid hormone secretion
Muscle tissue disease
Short stature
Decreased body height
Small stature

[ more ]

30%-79% of people have these symptoms
Abnormality of dental enamel
Abnormal tooth enamel
Enamel abnormalities
Enamel abnormality

[ more ]

Abnormal heart rate
Heart rhythm disorders
Irregular heart beat
Irregular heartbeat

[ more ]

Clouding of the lens of the eye
Cloudy lens

[ more ]

Cerebral calcification
Abnormal deposits of calcium in the brain
Delayed eruption of teeth
Delayed eruption
Delayed teeth eruption
Delayed tooth eruption
Eruption, delayed
Late eruption of teeth
Late tooth eruption

[ more ]

Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
Autosomal recessive inheritance
Decreased circulating parathyroid hormone level
High blood phosphate levels
Intermittent involuntary muscle spasm


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

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    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.

    In-Depth Information

    • 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 hypoparathyroidism. Click on the link to view a sample search on this topic.