Normal Function
The GCM2 gene provides instructions for making a protein that is primarily found in the parathyroid glands. These four glands are located in the neck and produce a hormone called parathyroid hormone that regulates the levels of calcium in the blood. The GCM2 protein is needed for the development of the parathyroid glands before birth, and it plays a role in the maintenance of these glands into adulthood.
The GCM2 protein acts as a transcription factor, which means that it binds to specific regions of DNA and helps control the activity of genes. As a transcription factor, it is likely that the GCM2 protein helps produce parathyroid hormone.
Health Conditions Related to Genetic Changes
Familial isolated hyperparathyroidism
Variants (also called mutations) in the GCM2 gene can increase the risk of developing familial isolated hyperparathyroidism, a condition that is characterized by overactive parathyroid glands (hyperparathyroidism). These four glands are located in the neck and release a hormone that helps regulate the levels of calcium in the blood. This regulation is disrupted in people with familial isolated hyperparathyroidism, which can lead to high blood calcium levels (hypercalcemia), kidney stones, thinning of the bones (osteoporosis), nausea, vomiting, high blood pressure (hypertension), weakness, and fatigue.
Most of the GCM2 gene variants that are associated with familial isolated hyperparathyroidism lead to the substitution of one protein building block (amino acid) for another in the GCM2 protein. These changes cause cells to produce an overactive version of the GCM2 protein that likely leads to the overproduction of parathyroid hormone. As a result, more calcium could be released into the blood, causing people to have an increased risk of developing the signs and symptoms of familial isolated hyperparathyroidism.
More About This Health ConditionOther disorders
Variants in the GCM2 gene can also cause isolated hypoparathyroidism, a condition that is characterized by a shortage of parathyroid hormone (hypoparathyroidism). People with isolated hypoparathyroidism often have low levels of calcium in the blood (hypocalemia). Hypocalcemia can cause muscle cramping and other health problems, although many people with this condition have no associated health problems.
Most of the GCM2 gene variants that cause isolated hypoparathyroidism cause cells to produce an altered or abnormally shortened version of the GCM2 protein that does not function properly. As a result, the parathyroid glands produce less parathyroid hormone. Without enough parathyroid hormone, blood levels of calcium are kept low, leading to the signs and symptoms of isolated hypoparathyroidism.
Other Names for This Gene
- GCMB
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
References
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- Guan B, Welch JM, Sapp JC, Ling H, Li Y, Johnston JJ, Kebebew E, Biesecker LG, Simonds WF, Marx SJ, Agarwal SK. GCM2-Activating Mutations in Familial Isolated Hyperparathyroidism. Am J Hum Genet. 2016 Nov 3;99(5):1034-1044. doi: 10.1016/j.ajhg.2016.08.018. Epub 2016 Oct 13. Citation on PubMed
- Vincze S, Peters NV, Kuo CL, Brown TC, Korah R, Murtha TD, Bellizzi J, Riccardi A, Parham K, Carling T, Costa-Guda J, Arnold A. GCM2 Variants in Familial and Multiglandular Primary Hyperparathyroidism. J Clin Endocrinol Metab. 2022 Apr 19;107(5):e2021-e2026. doi: 10.1210/clinem/dgab929. Citation on PubMed
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