Skip Navigation
Genetics Home Reference: your guide to understanding genetic conditions
http://ghr.nlm.nih.gov/     A service of the U.S. National Library of Medicine®

ABCA4

Reviewed November 2010

What is the official name of the ABCA4 gene?

The official name of this gene is “ATP-binding cassette, sub-family A (ABC1), member 4.”

ABCA4 is the gene's official symbol. The ABCA4 gene is also known by other names, listed below.

What is the normal function of the ABCA4 gene?

The ABCA4 gene provides instructions for making a protein that is found in the retina, the specialized light-sensitive tissue that lines the back of the eye. Specifically, the ABCA4 protein is produced in the retina's specialized light receptor cells (photoreceptors). The ABCA4 protein is active following phototransduction, the process by which light entering the eye is converted into electrical signals that are transmitted to the brain. Phototransduction leads to the formation of potentially toxic substances. The ABCA4 protein removes one of these substances, called N-retinylidene-PE, from photoreceptor cells.

Does the ABCA4 gene share characteristics with other genes?

The ABCA4 gene belongs to a family of genes called ABC (ATP-binding cassette transporters).

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 ABCA4 gene related to health conditions?

Stargardt macular degeneration - caused by mutations in the ABCA4 gene

More than 500 mutations in the ABCA4 gene have been found to cause Stargardt macular degeneration. Most of these mutations change single protein building blocks (amino acids) in the ABCA4 protein. A malfunctioning ABCA4 protein cannot remove N-retinylidene-PE from photoreceptor cells. As a result, N-retinylidene-PE combines with another substance to produce a fatty yellow pigment called lipofuscin, which builds up in retinal cells. The buildup of lipofuscin is toxic to the cells of the retina and causes progressive vision loss in people with Stargardt macular degeneration. In most cases, Stargardt macular degeneration is caused by mutations in the ABCA4 gene.

other retinal dystrophies - associated with the ABCA4 gene

Mutations in the ABCA4 gene have also been found to cause a vision disorder called cone-rod dystrophy. The vision problems associated with this condition include a loss of sharpness (reduced acuity), an increased sensitivity to light (photophobia), nearsightedness (myopia), and impaired color vision. These vision problems tend to worsen over time. Most of the ABCA4 gene mutations that cause cone-rod dystrophy change single amino acids in the ABCA4 protein. It is estimated that ABCA4 gene mutations account for 30 to 60 percent of cases of cone-rod dystrophy.

Some studies have suggested that ABCA4 gene mutations are associated with an increased risk for developing age-related macular degeneration. This eye disease is a leading cause of vision loss among older people worldwide. It is characterized by damage to the retina and a loss of visual acuity. While some studies have found an association between ABCA4 gene mutations and age-related macular degeneration, other studies have not found this association. A combination of genetic and environmental factors likely determines the risk of developing this disease.

Where is the ABCA4 gene located?

Cytogenetic Location: 1p22

Molecular Location on chromosome 1: base pairs 94,458,392 to 94,586,704

The ABCA4 gene is located on the short (p) arm of chromosome 1 at position 22.

The ABCA4 gene is located on the short (p) arm of chromosome 1 at position 22.

More precisely, the ABCA4 gene is located from base pair 94,458,392 to base pair 94,586,704 on chromosome 1.

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 ABCA4?

You and your healthcare professional may find the following resources about ABCA4 helpful.

  • Educational resources - Information pages

    • The Human ATP-Binding Cassette (ABC) Transporter Superfamily (2002): ABCA4 (http://www.ncbi.nlm.nih.gov/books/NBK31/)
    • Webvision: The Organization of the Retina and Visual System (2007): Photoreceptors (http://www.ncbi.nlm.nih.gov/books/NBK11522/)
  • Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/books/NBK1417/)

  • Genetic Testing Registry - Repository of genetic test information

    • GTR: Genetic tests for ABCA4 (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=24%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=(ABCA4%5BTIAB%5D)%20AND%20((Genes%5BMH%5D)%20OR%20(Genetic%20Phenomena%5BMH%5D))%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%201080%20days%22%5Bdp%5D)

  • OMIM - Genetic disorder catalog

    • CONE-ROD DYSTROPHY 3 (http://omim.org/entry/604116)
    • MACULAR DEGENERATION, AGE-RELATED, 2 (http://omim.org/entry/153800)
    • ATP-BINDING CASSETTE, SUBFAMILY A, MEMBER 4 (http://omim.org/entry/601691)
    • RETINITIS PIGMENTOSA 19 (http://omim.org/entry/601718)
    • STARGARDT DISEASE 1 (http://omim.org/entry/248200)

  • Research Resources - Tools for researchers

    • Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/24)
    • GeneCards (http://www.genecards.org/cgi-bin/carddisp.pl?id_type=entrezgene&id=24)
    • HUGO Gene Nomenclature Committee (http://www.genenames.org/data/hgnc_data.php?hgnc_id=34)

What other names do people use for the ABCA4 gene or gene products?

  • ABCA4_HUMAN
  • ABCR
  • ATP-binding cassette sub-family A member 4
  • ATP-binding cassette transporter, retinal-specific
  • photoreceptor rim protein
  • retinal-specific ATP-binding cassette transporter
  • retina-specific ABC transporter
  • RIM ABC transporter
  • RIM protein
  • RMP

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 ABCA4?

acids ; ATP ; gene ; lipofuscin ; macular degeneration ; myopia ; nearsightedness ; photophobia ; photoreceptor ; pigment ; protein ; receptor ; retina ; sensitivity ; tissue ; toxic ; visual acuity

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

References

  • Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/24)
  • Molday RS, Zhang K. Defective lipid transport and biosynthesis in recessive and dominant Stargardt macular degeneration. Prog Lipid Res. 2010 Oct;49(4):476-92. doi: 10.1016/j.plipres.2010.07.002. Epub 2010 Jul 13. Review. (http://www.ncbi.nlm.nih.gov/pubmed/20633576?dopt=Abstract)
  • Molday RS, Zhong M, Quazi F. The role of the photoreceptor ABC transporter ABCA4 in lipid transport and Stargardt macular degeneration. Biochim Biophys Acta. 2009 Jul;1791(7):573-83. doi: 10.1016/j.bbalip.2009.02.004. Epub 2009 Feb 20. Review. (http://www.ncbi.nlm.nih.gov/pubmed/19230850?dopt=Abstract)
  • OMIM: ATP-BINDING CASSETTE, SUBFAMILY A, MEMBER 4 (http://omim.org/entry/601691)
  • Tsybovsky Y, Molday RS, Palczewski K. The ATP-binding cassette transporter ABCA4: structural and functional properties and role in retinal disease. Adv Exp Med Biol. 2010;703:105-25. doi: 10.1007/978-1-4419-5635-4_8. Review. (http://www.ncbi.nlm.nih.gov/pubmed/20711710?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.

 
Reviewed: November 2010
Published: May 20, 2013