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


Reviewed June 2006

What is the official name of the PKD2 gene?

The official name of this gene is “polycystin 2, transient receptor potential cation channel.”

PKD2 is the gene's official symbol. The PKD2 gene is also known by other names, listed below.

What is the normal function of the PKD2 gene?

The PKD2 gene provides instructions for making a protein called polycystin-2. This protein is found in the kidneys before birth and in many adult tissues. Although its exact function is not well understood, polycystin-2 can be regulated by a larger, somewhat similar protein called polycystin-1.

Polycystin-2 likely functions as a channel spanning the cell membrane of kidney cells. In conjunction with polycystin-1, the channel transports positively charged atoms (ions), particularly calcium ions, into the cell. This influx of calcium ions triggers a cascade of chemical reactions inside the cell that may instruct the cell to undergo certain changes, such as maturing to take on specialized functions. Polycystin-1 and polycystin-2 likely work together to help regulate cell growth and division (proliferation), cell movement (migration), and interactions with other cells.

Polycystin-2 is also active in other parts of the cell, including cellular structures called primary cilia. Primary cilia are tiny, fingerlike projections that line the small tubes where urine is formed (renal tubules). Researchers believe that primary cilia sense the movement of fluid through these tubules, which appears to help maintain the tubules' size and structure. The interaction of polycystin-1 and polycystin-2 in renal tubules promotes the normal development and function of the kidneys.

Does the PKD2 gene share characteristics with other genes?

The PKD2 gene belongs to a family of genes called EF-hand domain containing (EF-hand domain containing). It also belongs to a family of genes called TRP (transient receptor potential cation channels).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? ( in the Handbook.

How are changes in the PKD2 gene related to health conditions?

polycystic kidney disease - caused by mutations in the PKD2 gene

More than 75 mutations in the PKD2 gene have been identified in people with polycystic kidney disease. These mutations are responsible for about 15 percent of all cases of autosomal dominant polycystic kidney disease (ADPKD), which is the most common type of this disorder. Mutations in the PKD2 gene include changes in single DNA building blocks (base pairs) and deletions or insertions of a small number of base pairs in the gene. Most PKD2 mutations are predicted to result in the production of an abnormally small, nonfunctional version of the polycystin-2 protein. Although researchers are uncertain how a lack of polycystin-2 leads to the formation of cysts, it likely disrupts the protein's interaction with polycystin-1 and alters signaling within the cell and in primary cilia. As a result, cells lining the renal tubules may grow and divide abnormally, leading to the growth of numerous cysts characteristic of polycystic kidney disease.

Where is the PKD2 gene located?

Cytogenetic Location: 4q22.1

Molecular Location on chromosome 4: base pairs 88,007,639 to 88,077,779

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

The PKD2 gene is located on the long (q) arm of chromosome 4 at position 22.1.

The PKD2 gene is located on the long (q) arm of chromosome 4 at position 22.1.

More precisely, the PKD2 gene is located from base pair 88,007,639 to base pair 88,077,779 on chromosome 4.

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

Where can I find additional information about PKD2?

You and your healthcare professional may find the following resources about PKD2 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 PKD2 gene or gene products?

  • APKD2
  • PC2
  • Pc-2
  • PKD4
  • polycystic kidney disease 2 (autosomal dominant)
  • polycystin-2
  • TRPP2

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

What glossary definitions help with understanding PKD2?

autosomal ; autosomal dominant ; calcium ; cation ; cell ; cell membrane ; channel ; cysts ; DNA ; gene ; ions ; kidney ; polycystic kidney ; proliferation ; protein ; receptor ; renal ; transient

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


  • Al-Bhalal L, Akhtar M. Molecular basis of autosomal dominant polycystic kidney disease. Adv Anat Pathol. 2005 May;12(3):126-33. Review. (
  • Bissler JJ, Dixon BP. A mechanistic approach to inherited polycystic kidney disease. Pediatr Nephrol. 2005 May;20(5):558-66. Epub 2005 Feb 18. Review. (
  • Boucher C, Sandford R. Autosomal dominant polycystic kidney disease (ADPKD, MIM 173900, PKD1 and PKD2 genes, protein products known as polycystin-1 and polycystin-2). Eur J Hum Genet. 2004 May;12(5):347-54. Review. (
  • Gene Review: Polycystic Kidney Disease, Autosomal Dominant (
  • Grimm DH, Karihaloo A, Cai Y, Somlo S, Cantley LG, Caplan MJ. Polycystin-2 regulates proliferation and branching morphogenesis in kidney epithelial cells. J Biol Chem. 2006 Jan 6;281(1):137-44. Epub 2005 Nov 8. (
  • Lina F, Satlinb LM. Polycystic kidney disease: the cilium as a common pathway in cystogenesis. Curr Opin Pediatr. 2004 Apr;16(2):171-6. Review. (
  • Nauli SM, Alenghat FJ, Luo Y, Williams E, Vassilev P, Li X, Elia AE, Lu W, Brown EM, Quinn SJ, Ingber DE, Zhou J. Polycystins 1 and 2 mediate mechanosensation in the primary cilium of kidney cells. Nat Genet. 2003 Feb;33(2):129-37. Epub 2003 Jan 6. (
  • NCBI Gene (
  • Ong AC, Harris PC. Molecular pathogenesis of ADPKD: the polycystin complex gets complex. Kidney Int. 2005 Apr;67(4):1234-47. (
  • Wilson PD. Polycystic kidney disease. N Engl J Med. 2004 Jan 8;350(2):151-64. 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: June 2006
Published: February 8, 2016