ATP8B1

Reviewed April 2012

What is the official name of the ATP8B1 gene?

The official name of this gene is “ATPase, aminophospholipid transporter, class I, type 8B, member 1.”

ATP8B1 is the gene's official symbol. The ATP8B1 gene is also known by other names, listed below.

What is the normal function of the ATP8B1 gene?

The ATP8B1 gene (also known as FIC1) provides instructions for making a protein that is found throughout the body. It is thought to control the distribution of certain fat molecules known as aminophospholipids on the inner surface of liver cell membranes. Based on this role, the ATP8B1 protein is sometimes known as an aminophospholipid translocase. In particular, this protein performs its function in the membranes of liver cells that transport fat-digesting acids called bile acids into bile, and it likely plays a role in maintaining an appropriate balance of bile acids. This process, known as bile acid homeostasis, is critical for the normal secretion of bile and the proper functioning of liver cells.

Does the ATP8B1 gene share characteristics with other genes?

The ATP8B1 gene belongs to a family of genes called ATP (ATPase superfamily).

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 ATP8B1 gene related to health conditions?

benign recurrent intrahepatic cholestasis - caused by mutations in the ATP8B1 gene: Mutations in the ATP8B1 gene can cause benign recurrent intrahepatic cholestasis type 1 (BRIC1). People with BRIC1 have occasional episodes of impaired bile secretion that lead to severe itching (pruritus), and yellowing of the skin and whites of the eyes (jaundice). Most ATP8B1 gene mutations that cause BRIC1 change single protein building blocks (amino acids) in the ATP8B1 protein. These mutations likely alter the structure or function of the ATP8B1 protein only moderately. Through unknown mechanisms, mutations in the ATP8B1 gene result in the buildup of bile acids in liver cells, which leads to the signs and symptoms of BRIC1. It is unclear what causes the episodes to begin or end. On occasion, people with BRIC1 have been later diagnosed with a more severe condition called progressive familial intrahepatic cholestasis (described below) when their symptoms worsened.
progressive familial intrahepatic cholestasis - caused by mutations in the ATP8B1 gene: More than 50 mutations in the ATP8B1 gene have been found to cause a severe form of liver disease called progressive familial intrahepatic cholestasis type 1 (PFIC1). Most mutations in the ATP8B1 gene that cause PFIC1 remove large portions of the gene or lead to an abnormally short protein. These mutations are likely to severely alter the structure or function of the ATP8B1 protein. These mutations cause bile acids to build up in liver cells, damaging these cells and causing liver disease. Although the ATP8B1 protein is found throughout the body, it is unclear how a lack of this protein causes short stature, deafness, diarrhea, and other signs and symptoms of PFIC1.

Where is the ATP8B1 gene located?

Cytogenetic Location: 18q21.31

Molecular Location on chromosome 18: base pairs 55,313,657 to 55,470,326

The ATP8B1 gene is located on the long (q) arm of chromosome 18 at position 21.31.

More precisely, the ATP8B1 gene is located from base pair 55,313,657 to base pair 55,470,326 on chromosome 18.

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 ATP8B1?

You and your healthcare professional may find the following resources about ATP8B1 helpful.

Educational resources - Information pages
- Madame Curie Bioscience Database: Fat Absorption and Lipid Metabolism in Cholestasis (http://www.ncbi.nlm.nih.gov/books/NBK6420/)
- Madame Curie Bioscience Database: Genetics of Cholestatic Disorders (http://www.ncbi.nlm.nih.gov/books/NBK6475/)
Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/books/NBK1297/)
Genetic Testing Registry - Repository of genetic test information
- GTR: Genetic tests for ATP8B1 (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=5205%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=(ATP8B1%5BTIAB%5D)%20OR%20(FIC1%5BTIAB%5D)%20AND%20((Genes%5BMH%5D)%20OR%20(Genetic%20Phenomena%5BMH%5D))%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%203600%20days%22%5Bdp%5D)
OMIM - Genetic disorder catalog (http://omim.org/entry/602397)
Research Resources - Tools for researchers
- Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://atlasgeneticsoncology.org/Genes/GC_ATP8B1.html)
- Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/5205)
- GeneCards (http://www.genecards.org/cgi-bin/carddisp.pl?id_type=entrezgene&id=5205)
- HUGO Gene Nomenclature Committee (http://www.genenames.org/data/hgnc_data.php?hgnc_id=3706)

What other names do people use for the ATP8B1 gene or gene products?

AT8B1_HUMAN
BRIC
FIC1
PFIC
PFIC1

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 ATP8B1?

acids ; benign ; bile ; cell ; class ; familial ; gene ; homeostasis ; jaundice ; protein ; secretion ; short stature ; stature

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

Cai SY, Gautam S, Nguyen T, Soroka CJ, Rahner C, Boyer JL. ATP8B1 deficiency disrupts the bile canalicular membrane bilayer structure in hepatocytes, but FXR expression and activity are maintained. Gastroenterology. 2009 Mar;136(3):1060-9. doi: 10.1053/j.gastro.2008.10.025. Epub 2008 Nov 1. (http://www.ncbi.nlm.nih.gov/pubmed/19027009?dopt=Abstract)
Davit-Spraul A, Gonzales E, Baussan C, Jacquemin E. Progressive familial intrahepatic cholestasis. Orphanet J Rare Dis. 2009 Jan 8;4:1. doi: 10.1186/1750-1172-4-1. Review. (http://www.ncbi.nlm.nih.gov/pubmed/19133130?dopt=Abstract)
Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/5205)
Folmer DE, van der Mark VA, Ho-Mok KS, Oude Elferink RP, Paulusma CC. Differential effects of progressive familial intrahepatic cholestasis type 1 and benign recurrent intrahepatic cholestasis type 1 mutations on canalicular localization of ATP8B1. Hepatology. 2009 Nov;50(5):1597-605. doi: 10.1002/hep.23158. (http://www.ncbi.nlm.nih.gov/pubmed/19731236?dopt=Abstract)
Jansen PL, Sturm E. Genetic cholestasis, causes and consequences for hepatobiliary transport. Liver Int. 2003 Oct;23(5):315-22. Review. (http://www.ncbi.nlm.nih.gov/pubmed/14708891?dopt=Abstract)
Klomp LW, Vargas JC, van Mil SW, Pawlikowska L, Strautnieks SS, van Eijk MJ, Juijn JA, Pabón-Peña C, Smith LB, DeYoung JA, Byrne JA, Gombert J, van der Brugge G, Berger R, Jankowska I, Pawlowska J, Villa E, Knisely AS, Thompson RJ, Freimer NB, Houwen RH, Bull LN. Characterization of mutations in ATP8B1 associated with hereditary cholestasis. Hepatology. 2004 Jul;40(1):27-38. (http://www.ncbi.nlm.nih.gov/pubmed/15239083?dopt=Abstract)
OMIM: ATPase, CLASS I, TYPE 8B, MEMBER 1 (http://omim.org/entry/602397)
Pauli-Magnus C, Stieger B, Meier Y, Kullak-Ublick GA, Meier PJ. Enterohepatic transport of bile salts and genetics of cholestasis. J Hepatol. 2005 Aug;43(2):342-57. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15975683?dopt=Abstract)
Paulusma CC, de Waart DR, Kunne C, Mok KS, Elferink RP. Activity of the bile salt export pump (ABCB11) is critically dependent on canalicular membrane cholesterol content. J Biol Chem. 2009 Apr 10;284(15):9947-54. doi: 10.1074/jbc.M808667200. Epub 2009 Feb 19. (http://www.ncbi.nlm.nih.gov/pubmed/19228692?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 healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.



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