Skip navigation
URL of this page: https://medlineplus.gov/genetics/gene/fancg/

FANCG gene

FA complementation group G

Normal Function

The FANCG gene provides instructions for making a protein that is involved in a process known as the Fanconi anemia (FA) pathway. The FA pathway turns on (activates) when the process of making new copies of DNA, called DNA replication, is blocked due to DNA damage. The FA pathway works to prevent a certain type of DNA damage known as interstrand cross-links (ICLs). ICLs are abnormal connections between two DNA building blocks (nucleotides) on opposite strands of DNA. These cross-links stop the process of DNA replication and can be caused by a buildup of toxic substances produced in the body or by treatment with certain cancer therapy drugs (sometimes known as DNA cross-linking agents).

The FANCG protein is one of several proteins that form a group known as the FA core complex. The FA core complex is composed of eight FA proteins (including FANCG) and two proteins called Fanconi anemia-associated proteins (FAAPs). This complex activates two proteins, called FANCD2 and FANCI, by attaching a single molecule called ubiquitin to each of them (a process called monoubiquitination). The activation of FANCD2 and FANCI attracts DNA repair proteins to the area of DNA damage so the cross-link can be corrected and DNA replication can continue.

Health Conditions Related to Genetic Changes

Fanconi anemia

Many variants (also called mutations) in the FANCG gene have been found to cause Fanconi anemia, a disorder that is characterized by a decrease in bone marrow function, an increased cancer risk, and physical differences. About 10 percent of all cases of Fanconi anemia are caused by variants in the FANCG gene. When Fanconi anemia results from variants in this gene, it is often associated with a more severe shortage of blood cells and a greater risk of developing cancer of the blood-forming cells (leukemia) than when the condition is caused by variants in other genes.

Most variants in the FANCG gene that cause Fanconi anemia lead to the production of a protein that does not function well or at all. This impacts the function of the FA core complex and disrupts the entire FA pathway. As a result, DNA damage is not repaired efficiently and ICLs build up over time. The ICLs impair DNA replication, which leads to either abnormal cell death due to an inability to make new DNA molecules or uncontrolled cell growth due to a lack of DNA repair. 

Cells that divide quickly, such as bone marrow cells and cells of the developing fetus, are particularly sensitive to problems with DNA replication. The death of these cells results in the decrease in blood cells and the physical differences that are seen in people with Fanconi anemia. When the buildup of errors in DNA leads to uncontrolled cell growth, affected individuals can develop leukemia or other cancers.

More About This Health Condition

Other Names for This Gene

  • FANCG_HUMAN
  • Fanconi anemia, complementation group G
  • XRCC9

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases

References

  • de Winter JP, Joenje H. The genetic and molecular basis of Fanconi anemia. Mutat Res. 2009 Jul 31;668(1-2):11-9. doi: 10.1016/j.mrfmmm.2008.11.004. Epub 2008 Nov 14. Citation on PubMed
  • Deakyne JS, Mazin AV. Fanconi anemia: at the crossroads of DNA repair. Biochemistry (Mosc). 2011 Jan;76(1):36-48. doi: 10.1134/s0006297911010068. Citation on PubMed
  • Kee Y, D'Andrea AD. Expanded roles of the Fanconi anemia pathway in preserving genomic stability. Genes Dev. 2010 Aug 15;24(16):1680-94. doi: 10.1101/gad.1955310. Citation on PubMed or Free article on PubMed Central
  • Kitao H, Takata M. Fanconi anemia: a disorder defective in the DNA damage response. Int J Hematol. 2011 Apr;93(4):417-424. doi: 10.1007/s12185-011-0777-z. Epub 2011 Feb 18. Citation on PubMed
  • Mathew CG. Fanconi anaemia genes and susceptibility to cancer. Oncogene. 2006 Sep 25;25(43):5875-84. doi: 10.1038/sj.onc.1209878. Citation on PubMed
  • Mehta PA, Ebens C. Fanconi Anemia. 2002 Feb 14 [updated 2021 Jun 3]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2025. Available from http://www.ncbi.nlm.nih.gov/books/NBK1401/ Citation on PubMed
  • Taniguchi T, D'Andrea AD. Molecular pathogenesis of Fanconi anemia: recent progress. Blood. 2006 Jun 1;107(11):4223-33. doi: 10.1182/blood-2005-10-4240. Epub 2006 Feb 21. Citation on PubMed

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.