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ABCB11

ATP binding cassette subfamily B member 11

The ABCB11 gene provides instructions for the bile salt export pump (BSEP) protein, crucial for bile production and liver health, with pathogenic variants linked to inherited cholestatic liver diseases. The ABCB11 gene encodes the bile salt export pump (BSEP), a protein exclusively found in the liver that is vital for transporting bile salts.

Chromosome 2q31.1 Autosomal recessive HGNC:42 Tier C
ABCB11 2q31.1 p arm q arm 2

ABCB11 is located on the long (q) arm of chromosome 2, at band 2q31.1. Arm ratio per GRCh38 - banding schematic.

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Clinical tests that include this

Carrier Screening panel
ABCB11 is 1 of 1,008 genes on this panel
Expanded carrier screening for recessive and X-linked conditions

Overview

The ABCB11 gene, also known as ATP binding cassette subfamily B member 11, provides the genetic blueprint for a protein called the bile salt export pump (BSEP). This protein is found specifically in the liver and plays a critical role in the formation of bile, a digestive fluid essential for breaking down dietary fats. Pathogenic variants in ABCB11 are associated with several inherited liver conditions characterised by impaired bile flow.

What the gene does

The ABCB11 gene's primary function is to direct the production of the BSEP protein, which is an integral part of liver cells. BSEP is responsible for actively transporting bile salts out of liver cells, where they are then combined with other substances to form bile. This process is crucial for normal digestion and for preventing the accumulation of toxic bile components within the liver. Impaired BSEP function, often due to pathogenic gene variants, can significantly reduce or eliminate this transport, leading to a build-up of bile salts within the liver cells and the development of cholestatic liver diseases.

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Chromosome location

The ABCB11 gene is located on chromosome 2, specifically at position 2q31.1. This genomic location specifies its precise address within the human genome.

Protein structure

The ABCB11 protein, BSEP, is 1321 amino acids long and contains several distinct functional regions and domains. It features a Disordered region at amino acids 16-37, and two ABC transmembrane type-1 domains located at amino acids 62-385 and 755-1043, respectively. Additionally, there are two ABC transporter domains, the first from amino acids 420-656 and the second from amino acids 1078-1316. A specific region from amino acids 651-672 is involved in Interaction with HAX1, and a short segment from amino acids 1311-1314 Mediates internalization from the plasma membrane.

Domain map · 1,321 amino acids
ABC transmembrane type-1 1 (62–385)ABC transporter 1 (420–656)Interaction with HAX1 (651–672)ABC transmembrane type-1 2 (755–1043)ABC transporter 2 (1078–1316)Mediates internalization from the plasma membrane (1311–1314)ABC transmembrane type62–385ABC transmembrane type755–1043ABC transporter 21078–13161~6611,321
Domain - independent functional unit
Region - functional region
🧬 Explore 3D structure on AlphaFold
UniProt:O95342Length:1,321 aaStructure:AlphaFold

Key variants

Variants within the ABCB11 gene can alter the function of the BSEP protein, leading to a range of inherited conditions. These changes can result in either reduced function or complete absence of the BSEP protein, impairing its ability to export bile salts from the liver.

1,870
Total variants catalogued in ClinVar
View all on ClinVar →
318 Pathogenic / Likely pathogenic 468 Uncertain significance 929 Benign / Likely benign 155 Conflicting or other

Sample of pathogenic variants

10 pathogenic / likely-pathogenic variants from ClinVar, ranked by review status (expert-panel-reviewed first). This is a sample; recurrent founder variants in a specific population may not appear here - see the full ClinVar listing via the link above.

Variant (HGVS) Protein change Classification Evidence Associated condition
c.1029C>G
single nucleotide variant
 p.Tyr343Ter Pathogenic/Likely pathogenic ★★☆☆ Benign recurrent intrahepatic cholestasis type 2
c.1029dup
Duplication
 p.Gly344fs Pathogenic/Likely pathogenic ★★☆☆ Benign recurrent intrahepatic cholestasis type 2
c.1062T>A
single nucleotide variant
 p.Tyr354Ter Pathogenic ★★☆☆ Benign recurrent intrahepatic cholestasis type 2
c.1069G>T
single nucleotide variant
 p.Gly357Ter Pathogenic ★★☆☆ not provided
c.1084-2A>G
single nucleotide variant
 - Pathogenic ★★☆☆ Familial intrahepatic cholestasis
c.1101_1102del
Deletion
 p.Val368fs Pathogenic ★★☆☆ Familial intrahepatic cholestasis
c.1156G>T
single nucleotide variant
 p.Gly386Ter Pathogenic ★★☆☆ Familial intrahepatic cholestasis type 2
c.1197+1G>T
single nucleotide variant
 - Pathogenic/Likely pathogenic ★★☆☆ Familial intrahepatic cholestasis
c.1198-1G>C
single nucleotide variant
 - Pathogenic/Likely pathogenic ★★☆☆ Benign recurrent intrahepatic cholestasis type 2
c.1243C>T
single nucleotide variant
 p.Arg415Ter Pathogenic ★★☆☆ not provided

Evidence stars indicate ClinVar review status. Individual variant interpretation should always be performed by a qualified clinical laboratory - many variants remain classified as Variants of Uncertain Significance (VUS) pending more research.

Associated conditions

Pathogenic variants in the ABCB11 gene are primarily associated with conditions that affect bile flow, collectively known as cholestasis. One notable condition is Progressive familial intrahepatic cholestasis type 2, often referred to as BSEP deficiency, which is characterised by chronic and progressive liver disease. Other associated conditions include benign recurrent intrahepatic cholestasis type 2 and intrahepatic cholestasis of pregnancy, both involving episodic or temporary impairments in bile excretion.

  • Progressive familial intrahepatic cholestasis type 2
    Hepatic & GI
    AR
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Inheritance pattern

Conditions caused by pathogenic ABCB11 variants typically follow autosomal recessive inheritance.

♀ Carrier parent 1 altered copy ♂ Carrier parent 1 altered copy Affected Carrier Carrier Unaffected Affected Carrier Unaffected Circles = females · Squares = males

When both parents are carriers, each child has a 25% chance of being affected, 50% of being a carrier, and 25% of being unaffected.

Carrier frequency by population How common is heterozygous ABCB11 carrier status across ancestry groups?

UK clinical status

The ABCB11 gene is recognised within the UK's NHS Genomic Medicine Service. It is included on several PanelApp panels, indicating its clinical relevance for genetic testing in the UK. These panels include Cholestasis, DDG2P, Likely inborn error of metabolism, Neonatal cholestasis, and Undiagnosed metabolic disorders, all showing a 'green' status for gene-disease validity.

Green-listed
High evidence · clinically actionable in NHS testing
Included in NHS GMS signed-off panels
Cholestasis · R171 NHS GMS → Likely inborn error of metabolism · R98 NHS GMS → DDG2P NHS GMS →
NHS Genomic Medicine Service Jeen carrier screening

Sources: NHS GMS PanelApp · Genomics England PanelApp · NHS National Genomic Test Directory

Frequently asked questions

What is the role of the ABCB11 gene?

The ABCB11 gene provides instructions for making the bile salt export pump (BSEP) protein, which is found in liver cells. This protein is essential for moving bile salts out of the liver, a critical step in producing bile and facilitating fat digestion.

What happens if the ABCB11 gene has a pathogenic variant?

Pathogenic variants in the ABCB11 gene can lead to reduced or absent function of the BSEP protein. This results in the accumulation of bile salts within liver cells, causing various forms of cholestasis, such as Progressive Familial Intrahepatic Cholestasis type 2.

Is ABCB11 associated with any specific liver diseases?

Yes, pathogenic variants in ABCB11 are primarily associated with Progressive familial intrahepatic cholestasis type 2 (PFIC2), also known as BSEP deficiency. They can also cause benign recurrent intrahepatic cholestasis type 2 and are implicated in intrahepatic cholestasis of pregnancy.

References

  1. Dixon PH, van Mil SW, Chambers J. Contribution of variant alleles of ABCB11 to susceptibility to intrahepatic cholestasis of pregnancy. Gut. 2009. PMID: 18987030
  2. Davit-Spraul A, Gonzales E, Baussan C. Progressive familial intrahepatic cholestasis. Orphanet journal of rare diseases. 2009. PMID: 19133130
  3. Geenes V, Williamson C. Intrahepatic cholestasis of pregnancy. World journal of gastroenterology. 2009. PMID: 19418576
  4. Meier Y, Zodan T, Lang C. Increased susceptibility for intrahepatic cholestasis of pregnancy and contraceptive-induced cholestasis in carriers of the 1331T>C polymorphism in the bile salt export pump. World journal of gastroenterology. 2008. PMID: 18176959
  5. Strautnieks SS, Byrne JA, Pawlikowska L. Severe bile salt export pump deficiency: 82 different ABCB11 mutations in 109 families. Gastroenterology. 2008. PMID: 18395098
  6. Meier Y, Pauli-Magnus C, Zanger UM. Interindividual variability of canalicular ATP-binding-cassette (ABC)-transporter expression in human liver. Hepatology (Baltimore, Md.). 2006. PMID: 16799996
  7. Pauli-Magnus C, Stieger B, Meier Y. Enterohepatic transport of bile salts and genetics of cholestasis. Journal of hepatology. 2005. PMID: 15975683
  8. Jansen PL, Sturm E. Genetic cholestasis, causes and consequences for hepatobiliary transport. Liver international : official journal of the International Association for the Study of the Liver. 2003. PMID: 14708891
  9. Strautnieks SS, Bull LN, Knisely AS. A gene encoding a liver-specific ABC transporter is mutated in progressive familial intrahepatic cholestasis. Nature genetics. 1998. PMID: 9806540
Educational content. This page is not medical or genetic advice, is not individually reviewed by a clinician for each reader, and should not replace a consultation with a qualified healthcare professional or genetic counsellor. If you are considering genetic testing or acting on a test result, book a consultation.
Data sources Last updated 4 October 2026. Content compiled from HGNC · MedlinePlus Genetics · ClinGen · Genomics England PanelApp · NHS National Genomic Test Directory · ClinVar · UniProt · AlphaFold .