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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.
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.
The ATP8B1 gene belongs to a family of genes called ATP (ATPases).
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.
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.
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.
Cytogenetic Location: 18q21.31
Molecular Location on chromosome 18: base pairs 57,646,425 to 57,803,309
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 57,646,425 to base pair 57,803,309 on chromosome 18.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
You and your healthcare professional may find the following resources about ATP8B1 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
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).
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.