National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Familial isolated hypoparathyroidism


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The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
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Orpha Number: 2238

Definition
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.

Etiology
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.
Last updated: 2/1/2005

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.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal calcium-phosphate regulating hormone level 0100530
Hypocalcemia
Low blood calcium levels
0002901
Hypoparathyroidism
Decreased parathyroid hormone secretion
0000829
Myopathy
Muscle tissue disease
0003198
Nephropathy 0000112
Seizure 0001250
Short stature
Decreased body height
Small stature
[ more ] 		0004322
30%-79% of people have these symptoms
Abnormality of dental enamel
Abnormal tooth enamel
Enamel abnormalities
Enamel abnormality
[ more ] 		0000682
Arrhythmia
Abnormal heart rate
Heart rhythm disorders
Irregular heart beat
Irregular heartbeat
[ more ] 		0011675
Cataract
Clouding of the lens of the eye
Cloudy lens
[ more ] 		0000518
Cerebral calcification
Abnormal deposits of calcium in the brain
0002514
Delayed eruption of teeth
Delayed eruption
Delayed teeth eruption
Delayed tooth eruption
Eruption, delayed
Late eruption of teeth
Late tooth eruption
[ more ] 		0000684
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance 0000006
Autosomal recessive inheritance 0000007
Decreased circulating parathyroid hormone level 0031817
Hyperphosphatemia
High blood phosphate levels
0002905
Tetany
Intermittent involuntary muscle spasm
0001281
Showing of 17 |
Last updated: 11/1/2020

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

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

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

  • The Assistance Fund provides various services, including education and financial aid, to help patients with a chronic or serious illness cover the cost of FDA-approved medications. Patients must be U.S citizens or permanent residents.

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.

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