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RPS6KA3 gene

ribosomal protein S6 kinase A3

Normal Function

The RPS6KA3 gene provides instructions for making a protein that is part of a family called ribosomal S6 kinases (RSKs). These proteins help regulate the activity of certain genes and are involved in signaling within cells. RSK proteins are thought to play a role in several important cellular processes including cell growth and division (proliferation), cell specialization (differentiation), and the self-destruction of cells (apoptosis).

The protein made by the RPS6KA3 gene appears to play an important role in the brain. The protein is involved in cell signaling pathways that are required for learning, the formation of long-term memories, and the survival of nerve cells.

Health Conditions Related to Genetic Changes

Coffin-Lowry syndrome

More than 125 mutations in the RPS6KA3 gene have been identified in people with Coffin-Lowry syndrome, a condition associated with intellectual disability and skeletal abnormalities. All of these mutations severely reduce or eliminate the activity of the RPS6KA3 protein. Some mutations insert or delete genetic material in the gene or change how the gene's instructions are used to build the protein. Other mutations change single protein building blocks (amino acids) in the RPS6KA3 protein.

Researchers do not fully understand how mutations in the RPS6KA3 gene lead to the signs and symptoms of Coffin-Lowry syndrome. A functional RPS6KA3 protein appears to be important for learning and memory, but its role in the skeleton is unknown.

More About This Health Condition

Other disorders

RPS6KA3 mutations have been identified in some people who have intellectual disability, but do not have most of the other characteristic features of Coffin-Lowry syndrome (described above). Because the RPS6KA3 gene is on the X chromosome, this condition is known as X-linked intellectual disability. Researchers believe that RPS6KA3 mutations are a rare cause of intellectual disability because only a few affected families have mutations in this gene.

Other Names for This Gene

  • HU-2
  • HU-3
  • Insulin-stimulated protein kinase 1
  • ISPK-1
  • MAP kinase-activated protein kinase 1b
  • MRX19
  • p90(rsk)
  • ribosomal protein S6 kinase, 90kDa, polypeptide 3
  • Ribosomal S6 kinase 2
  • RSK-2
  • RSK2

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


  • Delaunoy J, Abidi F, Zeniou M, Jacquot S, Merienne K, Pannetier S, Schmitt M, Schwartz C, Hanauer A. Mutations in the X-linked RSK2 gene (RPS6KA3) in patients with Coffin-Lowry syndrome. Hum Mutat. 2001 Feb;17(2):103-16. doi: 10.1002/1098-1004(200102)17:23.0.CO;2-N. Citation on PubMed
  • Delaunoy JP, Dubos A, Marques Pereira P, Hanauer A. Identification of novel mutations in the RSK2 gene (RPS6KA3) in patients with Coffin-Lowry syndrome. Clin Genet. 2006 Aug;70(2):161-6. doi: 10.1111/j.1399-0004.2006.00660.x. Citation on PubMed
  • Field M, Tarpey P, Boyle J, Edkins S, Goodship J, Luo Y, Moon J, Teague J, Stratton MR, Futreal PA, Wooster R, Raymond FL, Turner G. Mutations in the RSK2(RPS6KA3) gene cause Coffin-Lowry syndrome and nonsyndromic X-linked mental retardation. Clin Genet. 2006 Dec;70(6):509-15. doi: 10.1111/j.1399-0004.2006.00723.x. Citation on PubMed or Free article on PubMed Central
  • Guimiot F, Delezoide AL, Hanauer A, Simonneau M. Expression of the RSK2 gene during early human development. Gene Expr Patterns. 2004 Jan;4(1):111-4. doi: 10.1016/j.modgep.2003.06.001. Citation on PubMed
  • Hanauer A, Young ID. Coffin-Lowry syndrome: clinical and molecular features. J Med Genet. 2002 Oct;39(10):705-13. doi: 10.1136/jmg.39.10.705. Citation on PubMed or Free article on PubMed Central
  • Raymond FL. X linked mental retardation: a clinical guide. J Med Genet. 2006 Mar;43(3):193-200. doi: 10.1136/jmg.2005.033043. Epub 2005 Aug 23. Citation on PubMed or Free article on PubMed Central
  • Zeniou M, Ding T, Trivier E, Hanauer A. Expression analysis of RSK gene family members: the RSK2 gene, mutated in Coffin-Lowry syndrome, is prominently expressed in brain structures essential for cognitive function and learning. Hum Mol Genet. 2002 Nov 1;11(23):2929-40. doi: 10.1093/hmg/11.23.2929. Citation on PubMed
  • Zeniou M, Gattoni R, Hanauer A, Stevenin J. Delineation of the mechanisms of aberrant splicing caused by two unusual intronic mutations in the RSK2 gene involved in Coffin-Lowry syndrome. Nucleic Acids Res. 2004 Feb 18;32(3):1214-23. doi: 10.1093/nar/gkh272. Print 2004. Citation on PubMed or Free article on PubMed Central

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.