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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.

Read more about gene names and symbols on the About page.

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) (NCBIThis link leads to a site outside Genetics Home Reference.)

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

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

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.

See also Understanding Medical Terminology.

References (14 links)


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