Reviewed May 2013
What is the official name of the ABCG8 gene?
The official name of this gene is “ATP binding cassette subfamily G member 8.”
ABCG8 is the gene's official symbol. The ABCG8 gene is also known by other names, listed below.
What is the normal function of the ABCG8 gene?
The ABCG8 gene provides instructions for making sterolin-2, which makes up half of a protein called sterolin. The other half of the sterolin protein, sterolin-1, is produced from a gene called ABCG5. Sterolin is involved in eliminating plant sterols, which are fatty components of plant-based foods that cannot be used by human cells.
Sterolin is a transporter protein, which is a type of protein that moves substances across cell membranes. It is found mostly in cells of the intestines and liver and transports plant sterols. After plant sterols are absorbed from food into intestinal cells, the sterolin transporters in these cells pump them back into the intestinal tract. Sterolin transporters in liver cells pump the plant sterols into a fluid called bile that is released into the intestine. From the intestine, the plant sterols are eliminated with the feces. This process removes most of the dietary plant sterols, and allows only about 5 percent of these substances to get into the bloodstream. Sterolin also helps regulate levels of cholesterol, another fatty substance found in animal products, in a similar fashion; normally about 50 percent of cholesterol in the diet is absorbed by the body.
Does the ABCG8 gene share characteristics with other genes?
The ABCG8 gene belongs to a family of genes called ABC (ATP-binding cassette transporters).
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? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.
How are changes in the ABCG8 gene related to health conditions?
- sitosterolemia - caused by mutations in the ABCG8 gene
At least 28 ABCG8 gene mutations have been identified in people with sitosterolemia, which is a condition caused by accumulation of plant sterols. The mutations result in a defective sterolin transporter and impair the elimination of plant sterols and, to a lesser degree, cholesterol from the body. These fatty substances build up in the arteries, skin, and other tissues, resulting in clogged blood vessels that can impair blood flow (atherosclerosis), fatty skin growths (xanthomas), and the additional signs and symptoms of sitosterolemia. Excess plant sterols in red blood cells likely make their cell membranes stiff and prone to rupture, leading to a reduced number of red blood cells (anemia). Changes in the lipid composition of the membranes of red blood cells and platelets may account for the other blood abnormalities that sometimes occur in sitosterolemia.
- other disorders - increased risk from variations of the ABCG8 gene
Certain normal variations (polymorphisms) in the ABCG8 gene are associated with an increased risk of gallstones, which are small pebble-like deposits in the gallbladder or the bile ducts. Bile ducts carry bile (a fluid that helps digest fats) from the liver, where bile is produced, to the gallbladder, where it is stored, and to the small intestine, where it aids in digestion. Researchers suggest that the ABCG8 gene changes that increase the risk of gallstones may result in a sterolin transporter protein that pumps more cholesterol than usual into bile. This leads to the presence of more cholesterol than can be dissolved in the bile fluid in the bile ducts and gallbladder, resulting in the formation of gallstones.
Where is the ABCG8 gene located?
Cytogenetic Location: 2p21
Molecular Location on chromosome 2: base pairs 43,828,954 to 43,880,189
The ABCG8 gene is located on the short (p) arm of chromosome 2 at position 21.
More precisely, the ABCG8 gene is located from base pair 43,828,954 to base pair 43,880,189 on chromosome 2.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
Where can I find additional information about ABCG8?
You and your healthcare professional may find the following resources about ABCG8 helpful.
Educational resources - Information pages
- Madame Curie Bioscience Database: Fat Absorption and Lipid Metabolism in Cholestasis (http://www.ncbi.nlm.nih.gov/books/NBK6420/)
- The Human ATP-Binding Cassette (ABC) Transporter Superfamily: ABCG Genes (http://www.ncbi.nlm.nih.gov/books/NBK3/)
- Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/books/NBK131810)
Genetic Testing Registry - Repository of genetic test information
- GTR: Genetic tests for ABCG8 (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=64241%5Bgeneid%5D)
You may also be interested in these resources, which are designed for genetics professionals and researchers.
- PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/pubmed?term=%28ABCG8%5BTIAB%5D%29%20AND%20%28%28Genes%5BMH%5D%29%20OR%20%28Genetic%20Phenomena%5BMH%5D%29%29%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%201440%20days%22%5Bdp%5D)
- OMIM - Genetic disorder catalog (http://omim.org/entry/605460)
Research Resources - Tools for researchers
- Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://atlasgeneticsoncology.org/Genes/GC_ABCG8.html)
- HGNC Gene Family: ATP binding cassette subfamily G (http://www.genenames.org/cgi-bin/genefamilies/set/811)
- HGNC Gene Symbol Report (http://www.genenames.org/cgi-bin/gene_symbol_report?q=data/hgnc_data.php&hgnc_id=13887)
- NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/64241)
What other names do people use for the ABCG8 gene or gene products?
- ATP-binding cassette, subfamily G, member 8
- ATP-binding cassette sub-family G member 8
- ATP-binding cassette, sub-family G (WHITE), member 8
- sterolin 2
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
What glossary definitions help with understanding ABCG8?
You may find definitions for these and many other terms in the Genetics Home Reference
- OMIM: ATP-BINDING CASSETTE, SUBFAMILY G, MEMBER 8 (http://omim.org/entry/605460)
- Calandra S, Tarugi P, Speedy HE, Dean AF, Bertolini S, Shoulders CC. Mechanisms and genetic determinants regulating sterol absorption, circulating LDL levels, and sterol elimination: implications for classification and disease risk. J Lipid Res. 2011 Nov;52(11):1885-926. doi: 10.1194/jlr.R017855. Epub 2011 Aug 23. Review. (http://www.ncbi.nlm.nih.gov/pubmed/21862702?dopt=Abstract)
- Chan J, Vandeberg JL. Hepatobiliary transport in health and disease. Clin Lipidol. 2012 Apr;7(2):189-202. (http://www.ncbi.nlm.nih.gov/pubmed/22859919?dopt=Abstract)
- Fitzgerald ML, Mujawar Z, Tamehiro N. ABC transporters, atherosclerosis and inflammation. Atherosclerosis. 2010 Aug;211(2):361-70. doi: 10.1016/j.atherosclerosis.2010.01.011. Epub 2010 Jan 21. Review. (http://www.ncbi.nlm.nih.gov/pubmed/20138281?dopt=Abstract)
- Gene Review: Sitosterolemia (http://www.ncbi.nlm.nih.gov/books/NBK131810)
- Kerr ID, Haider AJ, Gelissen IC. The ABCG family of membrane-associated transporters: you don't have to be big to be mighty. Br J Pharmacol. 2011 Dec;164(7):1767-79. doi: 10.1111/j.1476-5381.2010.01177.x. Review. (http://www.ncbi.nlm.nih.gov/pubmed/21175590?dopt=Abstract)
- Kidambi S, Patel SB. Cholesterol and non-cholesterol sterol transporters: ABCG5, ABCG8 and NPC1L1: a review. Xenobiotica. 2008 Jul;38(7-8):1119-39. doi: 10.1080/00498250802007930 . Review. (http://www.ncbi.nlm.nih.gov/pubmed/18668442?dopt=Abstract)
- Kuo KK, Shin SJ, Chen ZC, Yang YH, Yang JF, Hsiao PJ. Significant association of ABCG5 604Q and ABCG8 D19H polymorphisms with gallstone disease. Br J Surg. 2008 Aug;95(8):1005-11. doi: 10.1002/bjs.6178. (http://www.ncbi.nlm.nih.gov/pubmed/18457353?dopt=Abstract)
- NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/64241)
- Niu DM, Chong KW, Hsu JH, Wu TJ, Yu HC, Huang CH, Lo MY, Kwok CF, Kratz LE, Ho LT. Clinical observations, molecular genetic analysis, and treatment of sitosterolemia in infants and children. J Inherit Metab Dis. 2010 Aug;33(4):437-43. doi: 10.1007/s10545-010-9126-2. Epub 2010 Jun 3. (http://www.ncbi.nlm.nih.gov/pubmed/20521169?dopt=Abstract)
- Rudkowska I, Jones PJ. Polymorphisms in ABCG5/G8 transporters linked to hypercholesterolemia and gallstone disease. Nutr Rev. 2008 Jun;66(6):343-8. doi: 10.1111/j.1753-4887.2008.00042.x. Review. (http://www.ncbi.nlm.nih.gov/pubmed/18522623?dopt=Abstract)
- Sabeva NS, Liu J, Graf GA. The ABCG5 ABCG8 sterol transporter and phytosterols: implications for cardiometabolic disease. Curr Opin Endocrinol Diabetes Obes. 2009 Apr;16(2):172-7. Review. (http://www.ncbi.nlm.nih.gov/pubmed/19306529?dopt=Abstract)
- Stender S, Frikke-Schmidt R, Nordestgaard BG, Tybjaerg-Hansen A. Sterol transporter adenosine triphosphate-binding cassette transporter G8, gallstones, and biliary cancer in 62,000 individuals from the general population. Hepatology. 2011 Feb;53(2):640-8. doi: 10.1002/hep.24046. Epub 2010 Dec 28. (http://www.ncbi.nlm.nih.gov/pubmed/21274884?dopt=Abstract)
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
See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.