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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed August 2012

What is the official name of the CDC73 gene?

The official name of this gene is “cell division cycle 73.”

CDC73 is the gene's official symbol. The CDC73 gene is also known by other names, listed below.

What is the normal function of the CDC73 gene?

The CDC73 gene (also known as the HRPT2 gene) provides instructions for making a protein called parafibromin. This protein is primarily found in the nucleus of cells and is likely involved in regulating gene transcription, which is the first step in protein production. Parafibromin is also thought to play a role in cell growth and division (proliferation), either promoting or inhibiting cell proliferation depending on signals within the cell. When parafibromin is found outside the nucleus, it appears to be involved in the organization of the cell's structural framework (the cytoskeleton).

How are changes in the CDC73 gene related to health conditions?

familial isolated hyperparathyroidism - caused by mutations in the CDC73 gene

Inherited mutations in the CDC73 gene have been found in some families with familial isolated hyperparathyroidism, a condition characterized by overactivity of the parathyroid glands (primary hyperparathyroidism). These glands release a hormone that helps control the normal balance of calcium in the blood. Primary hyperparathyroidism disrupts this balance, 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 in people with familial isolated hyperparathyroidism. Primary hyperparathyroidism is a characteristic feature of hyperparathyroidism-jaw tumor syndrome (described below); however, familial isolated hyperparathyroidism is diagnosed in people with hyperparathyroidism but not the other features of hyperparathyroidism-jaw tumor syndrome.

CDC73 gene mutations that cause familial isolated hyperparathyroidism likely result in decreased activity of the parafibromin protein. Reduced parafibromin activity can cause increased cell proliferation, leading to the the formation of tumors involving the parathyroid glands. Parathyroid tumors in people with familial isolated hyperparathyroidism are usually noncancerous. The resulting overactivity of the parathyroid glands causes the signs and symptoms of the condition. The mutations associated with familial isolated hyperparathyroidism are thought to have a less severe effect on protein function than those that cause hyperparathyroidism-jaw tumor syndrome. Occasionally, individuals with familial isolated hyperparathyroidism later develop features of hyperparathyroidism-jaw tumor syndrome, although some never do. Familial isolated hyperparathyroidism caused by CDC73 gene mutations may be an early or mild form of hyperparathyroidism-jaw tumor syndrome.

hyperparathyroidism-jaw tumor syndrome - caused by mutations in the CDC73 gene

More than 40 mutations in the CDC73 gene have been found to cause hyperparathyroidism-jaw tumor syndrome. Most of these mutations result in a parafibromin protein that is abnormally short and nonfunctional. Without functional parafibromin, cell proliferation is not properly regulated. Uncontrolled cell division resulting from the loss of parafibromin function can lead to the formation of tumors in the parathyroid glands, jaw, uterus, and kidneys in people with hyperparathyroidism-jaw tumor syndrome. Parathyroid tumors, which can be cancerous or noncancerous, interfere with the gland's normal function and lead to primary hyperparathyroidism, a characteristic feature of hyperparathyroidism-jaw tumor syndrome.

cancers - associated with the CDC73 gene

Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are called somatic mutations, are not inherited. Somatic changes in the CDC73 gene have been identified in many parathyroid cancers. These mutations prevent parafibromin from effectively regulating cell proliferation, leading to uncontrolled cell growth and tumor development. It is unclear why these mutations are associated with cancer in the parathyroid glands but not in other tissues in the body.

Where is the CDC73 gene located?

Cytogenetic Location: 1q25

Molecular Location on chromosome 1: base pairs 193,121,958 to 193,254,815

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The CDC73 gene is located on the long (q) arm of chromosome 1 at position 25.

The CDC73 gene is located on the long (q) arm of chromosome 1 at position 25.

More precisely, the CDC73 gene is located from base pair 193,121,958 to base pair 193,254,815 on chromosome 1.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about CDC73?

You and your healthcare professional may find the following resources about CDC73 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the CDC73 gene or gene products?

  • C1orf28
  • cell division cycle 73, Paf1/RNA polymerase II complex component, homolog (S. cerevisiae)
  • cell division cycle protein 73 homolog
  • HRPT2
  • hyperparathyroidism 2 protein
  • hyrax
  • HYX
  • parafibromin

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding CDC73?

calcium ; cancer ; cell ; cell division ; cell division cycle ; cell proliferation ; cytoskeleton ; familial ; gene ; gene transcription ; hormone ; hypercalcemia ; hyperparathyroidism ; hypertension ; inherited ; kidney ; kidney stones ; nucleus ; osteoporosis ; parathyroid ; proliferation ; protein ; RNA ; RNA polymerase ; syndrome ; transcription ; tumor

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Bradley KJ, Cavaco BM, Bowl MR, Harding B, Cranston T, Fratter C, Besser GM, Conceição Pereira M, Davie MW, Dudley N, Leite V, Sadler GP, Seller A, Thakker RV. Parafibromin mutations in hereditary hyperparathyroidism syndromes and parathyroid tumours. Clin Endocrinol (Oxf). 2006 Mar;64(3):299-306. (
  • Fernandez-Ranvier GG, Khanafshar E, Tacha D, Wong M, Kebebew E, Duh QY, Clark OH. Defining a molecular phenotype for benign and malignant parathyroid tumors. Cancer. 2009 Jan 15;115(2):334-44. doi: 10.1002/cncr.24037. (
  • Masi G, Barzon L, Iacobone M, Viel G, Porzionato A, Macchi V, De Caro R, Favia G, Palù G. Clinical, genetic, and histopathologic investigation of CDC73-related familial hyperparathyroidism. Endocr Relat Cancer. 2008 Dec;15(4):1115-26. doi: 10.1677/ERC-08-0066. Epub 2008 Aug 28. (
  • NCBI Gene (
  • Newey PJ, Bowl MR, Cranston T, Thakker RV. Cell division cycle protein 73 homolog (CDC73) mutations in the hyperparathyroidism-jaw tumor syndrome (HPT-JT) and parathyroid tumors. Hum Mutat. 2010 Mar;31(3):295-307. doi: 10.1002/humu.21188. (
  • Newey PJ, Bowl MR, Thakker RV. Parafibromin--functional insights. J Intern Med. 2009 Jul;266(1):84-98. doi: 10.1111/j.1365-2796.2009.02107.x. Review. (
  • Villablanca A, Calender A, Forsberg L, Höög A, Cheng JD, Petillo D, Bauters C, Kahnoski K, Ebeling T, Salmela P, Richardson AL, Delbridge L, Meyrier A, Proye C, Carpten JD, Teh BT, Robinson BG, Larsson C. Germline and de novo mutations in the HRPT2 tumour suppressor gene in familial isolated hyperparathyroidism (FIHP). J Med Genet. 2004 Mar;41(3):e32. (
  • Wang PF, Tan MH, Zhang C, Morreau H, Teh BT. HRPT2, a tumor suppressor gene for hyperparathyroidism-jaw tumor syndrome. Horm Metab Res. 2005 Jun;37(6):380-3. Review. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: August 2012
Published: February 1, 2016