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

GPC gene family

Reviewed February 2008

What are the GPC genes?

The GPC genes provide instructions for making proteins called glypicans. These proteins are part of a larger group of proteins (superfamily) called proteoglycans. Proteoglycans consist of a core protein attached to one or more long, straight sugar molecules called glycosaminoglycan (GAG) chains. Some functions of proteoglycans are determined by their GAG chains.

Six glypican genes (designated GPC1 through GPC6) have been identified in humans. The proteins produced from these genes are each attached to molecules of heparan sulfate, which are a type of GAG chain. Heparan sulfate allows glypicans to bind to a variety of other proteins. Because glypicans have heparan sulfate as their GAG chains, they are described as heparan sulfate proteoglycans (HSPGs).

Glypicans are anchored to the cell membrane, where they interact with growth factors, immune system proteins called cytokines, and other proteins outside the cell. Glypicans appear to play important roles in development before birth. These proteins are involved in numerous cell functions including regulating cell growth and division (cell proliferation), cell survival, cell movement (migration), and the process by which cells mature to carry out specific functions (differentiation).

Changes in glypican structure and function are associated with several human diseases. For example, mutations in the GPC3 gene underlie a condition called Simpson-Golabi-Behmel syndrome, which is characterized by overgrowth of the body and other birth defects. Additionally, increased and decreased activity of some glypican genes (including GPC1 and GPC3) have been found in certain forms of cancer.

Which genes are included in the GPC gene family?

The HUGO Gene Nomenclature Committee (HGNC) provides an index of gene families ( and their member genes.

Genetics Home Reference summarizes the normal function and health implications of this member of the GPC gene family: GPC3.

What conditions are related to genes in the GPC gene family?

Genetics Home Reference includes these conditions related to genes in the GPC gene family:

  • Simpson-Golabi-Behmel syndrome

Where can I find additional information about the GPC gene family?

You may find the following resources about the GPC gene family helpful.

  • Essentials of Glycobiology (1999): Proteoglycans and Glycosaminoglycans Are Components of Extracellular Matrices and Cell Surfaces ( (U.S. National Library of Medicine)
  • Molecular Biology of the Cell (fourth edition, 2002): Proteoglycans Are Composed of GAG Chains Covalently Linked to a Core Protein ( (U.S. National Library of Medicine)

What glossary definitions help with understanding the GPC gene family?

cancer ; cell ; cell membrane ; cell proliferation ; differentiation ; gene ; glycosylphosphatidylinositol ; heparan sulfate ; immune system ; proliferation ; protein ; proteoglycan ; sulfate ; syndrome

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


These sources were used to develop the Genetics Home Reference summary for the GPC gene family.

  • Filmus J, Selleck SB. Glypicans: proteoglycans with a surprise. J Clin Invest. 2001 Aug;108(4):497-501. Review. (
  • Fransson LA. Glypicans. Int J Biochem Cell Biol. 2003 Feb;35(2):125-9. Review. (
  • Fransson LA, Belting M, Cheng F, Jönsson M, Mani K, Sandgren S. Novel aspects of glypican glycobiology. Cell Mol Life Sci. 2004 May;61(9):1016-24. Review. (
  • Fico A, Maina F, Dono R. Fine-tuning of cell signaling by glypicans. Cell Mol Life Sci. 2011 Mar;68(6):923-9. Epub 2011 Feb 22. Review. (
  • Filmus J. Glypicans in growth control and cancer. Glycobiology. 2001 Mar;11(3):19R-23R. Review. (
  • Song HH, Filmus J. The role of glypicans in mammalian development. Biochim Biophys Acta. 2002 Dec 19;1573(3):241-6. 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: February 2008
Published: February 8, 2016