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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 2014

What is the official name of the COG5 gene?

The official name of this gene is “component of oligomeric golgi complex 5.”

COG5 is the gene's official symbol. The COG5 gene is also known by other names, listed below.

What is the normal function of the COG5 gene?

The COG5 gene provides instructions for making a protein called component of oligomeric Golgi complex 5 (COG5). As its name suggests, COG5 is one piece of a group of proteins known as the conserved oligomeric Golgi (COG) complex. This complex functions in the Golgi apparatus, which is a cell structure in which newly produced proteins are modified. One process that occurs in the Golgi apparatus is glycosylation, by which sugar molecules (oligosaccharides) are attached to proteins and fats. Glycosylation modifies proteins so they can perform a wider variety of functions.

The COG complex takes part in the transport of proteins, including the enzymes that perform glycosylation, within the Golgi apparatus. COG is specifically involved in retrograde transport, which moves proteins backward through the Golgi apparatus. Retrograde transport is important for recycling Golgi proteins and ensuring that they are in the correct location in the structure, which is key to proper glycosylation. The proteins are transported in sac-like structures called vesicles that attach to the Golgi membrane and release the contents into the Golgi apparatus. The COG complex controls the attachment (tethering) of the vesicles to the Golgi membrane.

How are changes in the COG5 gene related to health conditions?

COG5-congenital disorder of glycosylation - caused by mutations in the COG5 gene

At least eight mutations in the COG5 gene are known to cause COG5-congenital disorder of glycosylation (COG5-CDG). This condition often leads to developmental delay and intellectual disability and causes other abnormalities. Mutations in the COG5 gene reduce the amount of COG5 protein or eliminate it completely, which disrupts retrograde transport in the Golgi apparatus. This disruption results in abnormal protein glycosylation, which can affect multiple body systems, leading to the signs and symptoms of COG5-CDG. The severity of the condition is related to the amount of COG5 protein that remains in cells.

Where is the COG5 gene located?

Cytogenetic Location: 7q31

Molecular Location on chromosome 7: base pairs 107,201,744 to 107,564,514

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

The COG5 gene is located on the long (q) arm of chromosome 7 at position 31.

The COG5 gene is located on the long (q) arm of chromosome 7 at position 31.

More precisely, the COG5 gene is located from base pair 107,201,744 to base pair 107,564,514 on chromosome 7.

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

Where can I find additional information about COG5?

You and your healthcare professional may find the following resources about COG5 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 COG5 gene or gene products?

  • 13S golgi transport complex 1 90 kDa subunit
  • CDG2I
  • COG complex subunit 5
  • conserved oligomeric Golgi complex protein 5
  • conserved oligomeric Golgi complex subunit 5
  • GOLTC1
  • GTC90

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

What glossary definitions help with understanding COG5?

cell ; congenital ; developmental delay ; disability ; gene ; glycosylation ; Golgi apparatus ; Golgi complex ; oligosaccharides ; protein ; subunit

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


  • Fung CW, Matthijs G, Sturiale L, Garozzo D, Wong KY, Wong R, Wong V, Jaeken J. COG5-CDG with a Mild Neurohepatic Presentation. JIMD Rep. 2012;3:67-70. doi: 10.1007/8904_2011_61. Epub 2011 Sep 22. (
  • Miller VJ, Sharma P, Kudlyk TA, Frost L, Rofe AP, Watson IJ, Duden R, Lowe M, Lupashin VV, Ungar D. Molecular insights into vesicle tethering at the Golgi by the conserved oligomeric Golgi (COG) complex and the golgin TATA element modulatory factor (TMF). J Biol Chem. 2013 Feb 8;288(6):4229-40. doi: 10.1074/jbc.M112.426767. Epub 2012 Dec 13. (
  • NCBI Gene (
  • Oka T, Vasile E, Penman M, Novina CD, Dykxhoorn DM, Ungar D, Hughson FM, Krieger M. Genetic analysis of the subunit organization and function of the conserved oligomeric golgi (COG) complex: studies of COG5- and COG7-deficient mammalian cells. J Biol Chem. 2005 Sep 23;280(38):32736-45. Epub 2005 Jul 28. (
  • Reynders E, Foulquier F, Annaert W, Matthijs G. How Golgi glycosylation meets and needs trafficking: the case of the COG complex. Glycobiology. 2011 Jul;21(7):853-63. doi: 10.1093/glycob/cwq179. Epub 2010 Nov 26. Review. (
  • Rymen D, Keldermans L, Race V, Régal L, Deconinck N, Dionisi-Vici C, Fung CW, Sturiale L, Rosnoblet C, Foulquier F, Matthijs G, Jaeken J. COG5-CDG: expanding the clinical spectrum. Orphanet J Rare Dis. 2012 Dec 10;7:94. doi: 10.1186/1750-1172-7-94. Erratum in: Orphanet J Rare Dis. 2013;8:120. (
  • Smith RD, Lupashin VV. Role of the conserved oligomeric Golgi (COG) complex in protein glycosylation. Carbohydr Res. 2008 Aug 11;343(12):2024-31. doi: 10.1016/j.carres.2008.01.034. Epub 2008 Feb 2. 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 2014
Published: February 1, 2016