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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 2015

What is the official name of the ARHGAP31 gene?

The official name of this gene is “Rho GTPase activating protein 31.”

ARHGAP31 is the gene's official symbol. The ARHGAP31 gene is also known by other names, listed below.

What is the normal function of the ARHGAP31 gene?

The ARHGAP31 gene provides instructions for making a protein classified as a Rho GTPase activating protein (GAP). GAPs turn off (inactivate) proteins called GTPases, which play an important role in chemical signaling within cells. Often referred to as molecular switches, GTPases can be turned on and off. They are turned on (active) when they are attached (bound) to a molecule called GTP and are turned off when they are bound to another molecule called GDP. The ARHGAP31 protein inactivates GTPases known as Cdc42 and Rac1 by stimulating a reaction that turns the attached GTP into GDP. When active, Cdc42 and Rac1 transmit signals that are critical for various aspects of embryonic development. The ARHGAP31 protein appears to regulate these GTPases specifically during development of the limbs, skull, and heart.

Does the ARHGAP31 gene share characteristics with other genes?

The ARHGAP31 gene belongs to a family of genes called ARHGAP (Rho GTPase activating proteins).

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 ARHGAP31 gene related to health conditions?

Adams-Oliver syndrome - caused by mutations in the ARHGAP31 gene

At least three mutations in the ARHGAP31 gene are known to cause Adams-Oliver syndrome, a condition characterized by areas of missing skin (aplasia cutis congenita), usually on the scalp, and malformations of the hands and feet. These mutations lead to production of an abnormally short ARHGAP31 protein that is more active than normal. The increased GAP activity leads to a reduction in Cdc42 and Rac1 signaling, which impairs proper development of the skin on the top of the head and the bones in the hands and feet.

Where is the ARHGAP31 gene located?

Cytogenetic Location: 3q13.33

Molecular Location on chromosome 3: base pairs 119,294,289 to 119,419,476

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

The ARHGAP31 gene is located on the long (q) arm of chromosome 3 at position 13.33.

The ARHGAP31 gene is located on the long (q) arm of chromosome 3 at position 13.33.

More precisely, the ARHGAP31 gene is located from base pair 119,294,289 to base pair 119,419,476 on chromosome 3.

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

Where can I find additional information about ARHGAP31?

You and your healthcare professional may find the following resources about ARHGAP31 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 ARHGAP31 gene or gene products?

  • AOS1
  • Cdc42 GTPase-activating protein
  • rho GTPase-activating protein 31

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

What glossary definitions help with understanding ARHGAP31?

embryonic ; gene ; GTP ; hydrolysis ; molecule ; protein ; syndrome

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


  • Isrie M, Wuyts W, Van Esch H, Devriendt K. Isolated terminal limb reduction defects: extending the clinical spectrum of Adams-Oliver syndrome and ARHGAP31 mutations. Am J Med Genet A. 2014 Jun;164A(6):1576-9. doi: 10.1002/ajmg.a.36486. Epub 2014 Mar 25. (
  • NCBI Gene (
  • Raftopoulou M, Hall A. Cell migration: Rho GTPases lead the way. Dev Biol. 2004 Jan 1;265(1):23-32. Review. (
  • Southgate L, Machado RD, Snape KM, Primeau M, Dafou D, Ruddy DM, Branney PA, Fisher M, Lee GJ, Simpson MA, He Y, Bradshaw TY, Blaumeiser B, Winship WS, Reardon W, Maher ER, FitzPatrick DR, Wuyts W, Zenker M, Lamarche-Vane N, Trembath RC. Gain-of-function mutations of ARHGAP31, a Cdc42/Rac1 GTPase regulator, cause syndromic cutis aplasia and limb anomalies. Am J Hum Genet. 2011 May 13;88(5):574-85. doi: 10.1016/j.ajhg.2011.04.013. (
  • Tcherkezian J, Lamarche-Vane N. Current knowledge of the large RhoGAP family of proteins. Biol Cell. 2007 Feb;99(2):67-86. 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 2015
Published: February 8, 2016