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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed November 2012

What is the official name of the ABCA1 gene?

The official name of this gene is “ATP binding cassette subfamily A member 1.”

ABCA1 is the gene's official symbol. The ABCA1 gene is also known by other names, listed below.

What is the normal function of the ABCA1 gene?

The ABCA1 gene belongs to a group of genes called the ATP-binding cassette family, which provides instructions for making proteins that transport molecules across cell membranes. The ABCA1 protein is produced in many tissues, with high amounts found in the liver and in immune system cells called macrophages. This protein moves cholesterol and certain fats called phospholipids across the cell membrane to the outside of the cell. These substances are then picked up by a protein called apolipoprotein A-I (apoA-I), which is produced from the APOA1 gene. ApoA-I, cholesterol, and phospholipids combine to make high-density lipoprotein (HDL), often referred to as "good cholesterol" because high levels of this substance reduce the chances of developing heart and blood vessel (cardiovascular) disease. HDL is a molecule that carries cholesterol and phospholipids through the bloodstream from the body's tissues to the liver. Once in the liver, cholesterol and phospholipids are redistributed to other tissues or removed from the body. The process of removing excess cholesterol from cells is extremely important for balancing cholesterol levels and maintaining cardiovascular health.

Does the ABCA1 gene share characteristics with other genes?

The ABCA1 gene belongs to a family of genes called ABC (ATP-binding cassette transporters). It also 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? ( in the Handbook.

How are changes in the ABCA1 gene related to health conditions?

familial HDL deficiency - caused by mutations in the ABCA1 gene

Mutations in the ABCA1 gene can cause a condition called familial HDL deficiency. People with this condition have reduced levels of HDL in their blood and may experience early-onset cardiovascular disease, often before age 50. While one copy of the altered ABCA1 gene causes familial HDL deficiency, two copies of the altered gene cause a more severe related disorder called Tangier disease (described below).

Most ABCA1 gene mutations that cause familial HDL deficiency change single protein building blocks (amino acids) in the ABCA1 protein. These mutations prevent the release of cholesterol and phospholipids from cells, decreasing the amount of these substances available to form HDL. As a result, the levels of HDL in the blood are low. A shortage (deficiency) of HDL is believed to increase the risk of cardiovascular disease.

Tangier disease - caused by mutations in the ABCA1 gene

More than 30 mutations in the ABCA1 gene have been found to cause Tangier disease. Almost all of these mutations change single amino acids in the ABCA1 protein. These mutations prevent the release of cholesterol and phospholipids from cells. As a result, these substances accumulate within cells, causing certain body tissues to enlarge and the tonsils to acquire a yellowish-orange color. A buildup of cholesterol can be toxic to cells, leading to impaired cell function or cell death. In addition, the inability to transport cholesterol and phospholipids out of cells results in very low HDL levels, which may increase the risk of cardiovascular disease. These combined factors cause the signs and symptoms of Tangier disease.

Where is the ABCA1 gene located?

Cytogenetic Location: 9q31.1

Molecular Location on chromosome 9: base pairs 104,781,002 to 104,928,246

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

The ABCA1 gene is located on the long (q) arm of chromosome 9 at position 31.1.

The ABCA1 gene is located on the long (q) arm of chromosome 9 at position 31.1.

More precisely, the ABCA1 gene is located from base pair 104,781,002 to base pair 104,928,246 on chromosome 9.

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

Where can I find additional information about ABCA1?

You and your healthcare professional may find the following resources about ABCA1 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 ABCA1 gene or gene products?

  • ABC1
  • ATP-binding cassette 1
  • ATP-binding cassette, sub-family A (ABC1), member 1
  • ATP binding cassette transporter 1
  • CERP
  • cholesterol efflux regulatory protein
  • FLJ14958
  • HDLDT1
  • high density lipoprotein deficiency, Tangier type, 1
  • TGD

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

What glossary definitions help with understanding ABCA1?

acids ; apolipoprotein ; apolipoprotein A-I ; ATP ; cardiovascular ; cell ; cell membrane ; cholesterol ; deficiency ; familial ; gene ; HDL ; immune system ; lipoprotein ; molecule ; phospholipids ; protein ; toxic

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


  • Albrecht C, Viturro E. The ABCA subfamily--gene and protein structures, functions and associated hereditary diseases. Pflugers Arch. 2007 Feb;453(5):581-9. Epub 2006 Apr 4. Review. (
  • Batal R, Tremblay M, Krimbou L, Mamer O, Davignon J, Genest J Jr, Cohn JS. Familial HDL deficiency characterized by hypercatabolism of mature apoA-I but not proapoA-I. Arterioscler Thromb Vasc Biol. 1998 Apr;18(4):655-64. (
  • Bodzioch M, Orsó E, Klucken J, Langmann T, Böttcher A, Diederich W, Drobnik W, Barlage S, Büchler C, Porsch-Ozcürümez M, Kaminski WE, Hahmann HW, Oette K, Rothe G, Aslanidis C, Lackner KJ, Schmitz G. The gene encoding ATP-binding cassette transporter 1 is mutated in Tangier disease. Nat Genet. 1999 Aug;22(4):347-51. (
  • Brooks-Wilson A, Marcil M, Clee SM, Zhang LH, Roomp K, van Dam M, Yu L, Brewer C, Collins JA, Molhuizen HO, Loubser O, Ouelette BF, Fichter K, Ashbourne-Excoffon KJ, Sensen CW, Scherer S, Mott S, Denis M, Martindale D, Frohlich J, Morgan K, Koop B, Pimstone S, Kastelein JJ, Genest J Jr, Hayden MR. Mutations in ABC1 in Tangier disease and familial high-density lipoprotein deficiency. Nat Genet. 1999 Aug;22(4):336-45. (
  • Brunham LR, Kruit JK, Iqbal J, Fievet C, Timmins JM, Pape TD, Coburn BA, Bissada N, Staels B, Groen AK, Hussain MM, Parks JS, Kuipers F, Hayden MR. Intestinal ABCA1 directly contributes to HDL biogenesis in vivo. J Clin Invest. 2006 Apr;116(4):1052-62. Epub 2006 Mar 16. (
  • Iatan I, Alrasadi K, Ruel I, Alwaili K, Genest J. Effect of ABCA1 mutations on risk for myocardial infarction. Curr Atheroscler Rep. 2008 Oct;10(5):413-26. Review. (
  • Kolovou GD, Mikhailidis DP, Anagnostopoulou KK, Daskalopoulou SS, Cokkinos DV. Tangier disease four decades of research: a reflection of the importance of HDL. Curr Med Chem. 2006;13(7):771-82. Review. (
  • Marcil M, Brooks-Wilson A, Clee SM, Roomp K, Zhang LH, Yu L, Collins JA, van Dam M, Molhuizen HO, Loubster O, Ouellette BF, Sensen CW, Fichter K, Mott S, Denis M, Boucher B, Pimstone S, Genest J Jr, Kastelein JJ, Hayden MR. Mutations in the ABC1 gene in familial HDL deficiency with defective cholesterol efflux. Lancet. 1999 Oct 16;354(9187):1341-6. (
  • Mott S, Yu L, Marcil M, Boucher B, Rondeau C, Genest J Jr. Decreased cellular cholesterol efflux is a common cause of familial hypoalphalipoproteinemia: role of the ABCA1 gene mutations. Atherosclerosis. 2000 Oct;152(2):457-68. (
  • NCBI Gene (
  • Oram JF. HDL apolipoproteins and ABCA1: partners in the removal of excess cellular cholesterol. Arterioscler Thromb Vasc Biol. 2003 May 1;23(5):720-7. Epub 2003 Jan 9. Review. (
  • Rust S, Rosier M, Funke H, Real J, Amoura Z, Piette JC, Deleuze JF, Brewer HB, Duverger N, Denèfle P, Assmann G. Tangier disease is caused by mutations in the gene encoding ATP-binding cassette transporter 1. Nat Genet. 1999 Aug;22(4):352-5. (
  • Tall AR, Yvan-Charvet L, Terasaka N, Pagler T, Wang N. HDL, ABC transporters, and cholesterol efflux: implications for the treatment of atherosclerosis. Cell Metab. 2008 May;7(5):365-75. doi: 10.1016/j.cmet.2008.03.001. Review. (
  • Tang C, Oram JF. The cell cholesterol exporter ABCA1 as a protector from cardiovascular disease and diabetes. Biochim Biophys Acta. 2009 Jul;1791(7):563-72. doi: 10.1016/j.bbalip.2009.03.011. Epub 2009 Apr 1. 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: November 2012
Published: February 8, 2016