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


Reviewed June 2015

What is the official name of the SLC6A8 gene?

The official name of this gene is “solute carrier family 6 (neurotransmitter transporter), member 8.”

SLC6A8 is the gene's official symbol. The SLC6A8 gene is also known by other names, listed below.

What is the normal function of the SLC6A8 gene?

The SLC6A8 gene provides instructions for making a protein called sodium- and chloride-dependent creatine transporter 1. This protein transports the compound creatine into cells. Creatine is needed for the body to store and use energy properly.

Does the SLC6A8 gene share characteristics with other genes?

The SLC6A8 gene belongs to a family of genes called SLC (solute carriers).

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 SLC6A8 gene related to health conditions?

X-linked creatine deficiency - caused by mutations in the SLC6A8 gene

At least 80 mutations in the SLC6A8 gene have been identified in people with X-linked creatine deficiency, a disorder that causes intellectual disability, behavioral problems, seizures, and muscle weakness. SLC6A8 gene mutations impair the ability of the transporter protein to bring creatine into cells, resulting in a creatine shortage (deficiency). The effects of creatine deficiency are most severe in organs and tissues that require large amounts of energy, especially the brain.

Where is the SLC6A8 gene located?

Cytogenetic Location: Xq28

Molecular Location on the X chromosome: base pairs 153,688,297 to 153,696,593

The SLC6A8 gene is located on the long (q) arm of the X chromosome at position 28.

The SLC6A8 gene is located on the long (q) arm of the X chromosome at position 28.

More precisely, the SLC6A8 gene is located from base pair 153,688,297 to base pair 153,696,593 on the X chromosome.

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

Where can I find additional information about SLC6A8?

You and your healthcare professional may find the following resources about SLC6A8 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 SLC6A8 gene or gene products?

  • creatine transporter 1
  • creatine transporter SLC6A8
  • CRT
  • CRTR
  • CT1
  • MGC87396
  • sodium- and chloride-dependent creatine transporter 1
  • solute carrier family 6 member 8
  • solute carrier family 6 (neurotransmitter transporter, creatine), member 8

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

What glossary definitions help with understanding SLC6A8?

carrier ; chloride ; compound ; creatine ; deficiency ; disability ; gene ; protein ; sodium ; solute

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


  • Béard E, Braissant O. Synthesis and transport of creatine in the CNS: importance for cerebral functions. J Neurochem. 2010 Oct;115(2):297-313. doi: 10.1111/j.1471-4159.2010.06935.x. Epub 2010 Aug 25. Review. (
  • Braissant O, Henry H, Béard E, Uldry J. Creatine deficiency syndromes and the importance of creatine synthesis in the brain. Amino Acids. 2011 May;40(5):1315-24. doi: 10.1007/s00726-011-0852-z. Epub 2011 Mar 10. Review. (
  • Clark AJ, Rosenberg EH, Almeida LS, Wood TC, Jakobs C, Stevenson RE, Schwartz CE, Salomons GS. X-linked creatine transporter (SLC6A8) mutations in about 1% of males with mental retardation of unknown etiology. Hum Genet. 2006 Jul;119(6):604-10. Epub 2006 Apr 26. (
  • Nasrallah F, Feki M, Kaabachi N. Creatine and creatine deficiency syndromes: biochemical and clinical aspects. Pediatr Neurol. 2010 Mar;42(3):163-71. doi: 10.1016/j.pediatrneurol.2009.07.015. Review. (
  • NCBI Gene (
  • Rosenberg EH, Martínez Muñoz C, Betsalel OT, van Dooren SJ, Fernandez M, Jakobs C, deGrauw TJ, Kleefstra T, Schwartz CE, Salomons GS. Functional characterization of missense variants in the creatine transporter gene (SLC6A8): improved diagnostic application. Hum Mutat. 2007 Sep;28(9):890-6. (
  • Salomons GS, van Dooren SJ, Verhoeven NM, Marsden D, Schwartz C, Cecil KM, DeGrauw TJ, Jakobs C. X-linked creatine transporter defect: an overview. J Inherit Metab Dis. 2003;26(2-3):309-18. Review. (
  • Stockler-Ipsiroglu S, van Karnebeek CD. Cerebral creatine deficiencies: a group of treatable intellectual developmental disorders. Semin Neurol. 2014 Jul;34(3):350-6. doi: 10.1055/s-0034-1386772. Epub 2014 Sep 5. Review. Erratum in: Semin Neurol. 2014 Sep;34(4):479. (
  • Sykut-Cegielska J, Gradowska W, Mercimek-Mahmutoglu S, Stöckler-Ipsiroglu S. Biochemical and clinical characteristics of creatine deficiency syndromes. Acta Biochim Pol. 2004;51(4):875-82. Review. (
  • van de Kamp JM, Betsalel OT, Mercimek-Mahmutoglu S, Abulhoul L, Grünewald S, Anselm I, Azzouz H, Bratkovic D, de Brouwer A, Hamel B, Kleefstra T, Yntema H, Campistol J, Vilaseca MA, Cheillan D, D'Hooghe M, Diogo L, Garcia P, Valongo C, Fonseca M, Frints S, Wilcken B, von der Haar S, Meijers-Heijboer HE, Hofstede F, Johnson D, Kant SG, Lion-Francois L, Pitelet G, Longo N, Maat-Kievit JA, Monteiro JP, Munnich A, Muntau AC, Nassogne MC, Osaka H, Ounap K, Pinard JM, Quijano-Roy S, Poggenburg I, Poplawski N, Abdul-Rahman O, Ribes A, Arias A, Yaplito-Lee J, Schulze A, Schwartz CE, Schwenger S, Soares G, Sznajer Y, Valayannopoulos V, Van Esch H, Waltz S, Wamelink MM, Pouwels PJ, Errami A, van der Knaap MS, Jakobs C, Mancini GM, Salomons GS. Phenotype and genotype in 101 males with X-linked creatine transporter deficiency. J Med Genet. 2013 Jul;50(7):463-72. doi: 10.1136/jmedgenet-2013-101658. Epub 2013 May 3. (
  • van de Kamp JM, Mancini GM, Salomons GS. X-linked creatine transporter deficiency: clinical aspects and pathophysiology. J Inherit Metab Dis. 2014 Sep;37(5):715-33. doi: 10.1007/s10545-014-9713-8. Epub 2014 May 1. 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: June 2015
Published: November 23, 2015