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

BIRC gene family

Reviewed August 2010

What are the BIRC genes?

Genes in the BIRC family provide instructions for making inhibitors of apoptosis proteins (IAPs). IAPs help protect cells from self-destructing (undergoing apoptosis) by blocking (inhibiting) the action of certain enzymes called caspases, which are necessary for apoptosis.

IAPs each contain between one and three regions called baculovirus inhibitor repeat (BIR) domains, which attach (bind) to particular caspases. Some IAPs also have a region called a RING domain. The RING domain, in conjunction with other enzymes, can label target proteins with molecules called ubiquitins. This labeling can mark the target protein for destruction by a cellular mechanism called the ubiquitin-proteasome system.

Which genes are included in the BIRC gene family?

The HUGO Gene Nomenclature Committee (HGNC) provides an index of gene families ( and their member genes.

Genetics Home Reference summarizes the normal function and health implications of this member of the BIRC gene family: XIAP.

What conditions are related to genes in the BIRC gene family?

Genetics Home Reference includes these conditions related to genes in the BIRC gene family:

  • X-linked lymphoproliferative disease

What glossary definitions help with understanding the BIRC gene family?

apoptosis ; domain ; ligase ; proteasome ; protein ; ubiquitin

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


These sources were used to develop the Genetics Home Reference summary for the BIRC gene family.

  • Srinivasula SM, Ashwell JD. IAPs: what's in a name? Mol Cell. 2008 Apr 25;30(2):123-35. doi: 10.1016/j.molcel.2008.03.008. Review. (
  • Dubrez-Daloz L, Dupoux A, Cartier J. IAPs: more than just inhibitors of apoptosis proteins. Cell Cycle. 2008 Apr 15;7(8):1036-46. Epub 2008 Feb 11. Review. (
  • Ni T, Li W, Zou F. The ubiquitin ligase ability of IAPs regulates apoptosis. IUBMB Life. 2005 Dec;57(12):779-85. Review. (
  • Eckelman BP, Drag M, Snipas SJ, Salvesen GS. The mechanism of peptide-binding specificity of IAP BIR domains. Cell Death Differ. 2008 May;15(5):920-8. doi: 10.1038/cdd.2008.6. Epub 2008 Feb 1. (
  • Madame Curie Bioscience Database (2000-2010): Inhibitors of Apoptosis Proteins (IAPs) (


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: August 2010
Published: February 8, 2016