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


Reviewed April 2012

What is the official name of the SLC9A6 gene?

The official name of this gene is “solute carrier family 9, subfamily A (NHE6, cation proton antiporter 6), member 6.”

SLC9A6 is the gene's official symbol. The SLC9A6 gene is also known by other names, listed below.

What is the normal function of the SLC9A6 gene?

The SLC9A6 gene provides instructions for making a protein called sodium/hydrogen exchanger 6 (Na+/H+ exchanger 6 or NHE6). Na+/H+ exchangers are found in the membranes that surround cells or compartments within cells. These proteins act as channels that allow positively charged sodium atoms (Na+ ions) into the cell or cellular compartment in exchange for positively charged hydrogen ions (H+, also known as protons), which are removed. The exchange of hydrogen ions helps regulate the relative acidity (pH) of the cell or cellular compartment.

The NHE6 protein is found in the membrane of compartments within the cell known as endosomes, which recycle proteins and other cellular materials. The NHE6 protein controls the pH inside endosomes, which is important for the recycling function of these compartments. The NHE6 protein may have additional functions, such as helping to move proteins to the correct location in the cell (protein trafficking).

Does the SLC9A6 gene share characteristics with other genes?

The SLC9A6 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 SLC9A6 gene related to health conditions?

Christianson syndrome - caused by mutations in the SLC9A6 gene

Mutations in the SLC9A6 gene lead to Christianson syndrome. This condition is characterized by neurological problems, including intellectual disabilities, seizures, and an inability to walk or speak. Mutations in the SLC9A6 gene typically lead to an abnormally short NHE6 protein that is nonfunctional or that is broken down quickly in cells, resulting in the absence of functional NHE6 channels. As a result, the pH in endosomes is not properly maintained. It is unclear how unregulated endosomal pH leads to neurological problems in people with Christianson syndrome. Some studies have shown that protein trafficking by endosomes is important for learning and memory, but the role of endosomal pH or the NHE6 protein in this process has not been identified.

Where is the SLC9A6 gene located?

Cytogenetic Location: Xq26.3

Molecular Location on the X chromosome: base pairs 135,985,424 to 136,047,269

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

The SLC9A6 gene is located on the long (q) arm of the X chromosome at position 26.3.

The SLC9A6 gene is located on the long (q) arm of the X chromosome at position 26.3.

More precisely, the SLC9A6 gene is located from base pair 135,985,424 to base pair 136,047,269 on the X chromosome.

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

Where can I find additional information about SLC9A6?

You and your healthcare professional may find the following resources about SLC9A6 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 SLC9A6 gene or gene products?

  • KIAA0267
  • Na(+)/H(+) exchanger 6
  • NHE6
  • sodium/hydrogen exchanger 6
  • solute carrier family 9 (sodium/hydrogen exchanger), member 6

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

What glossary definitions help with understanding SLC9A6?

acidity ; carrier ; cation ; cell ; disabilities ; endosomes ; gene ; hydrogen ions ; ions ; Na ; neurological ; pH ; protein ; proton ; sodium ; solute ; syndrome

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


  • Brett CL, Wei Y, Donowitz M, Rao R. Human Na(+)/H(+) exchanger isoform 6 is found in recycling endosomes of cells, not in mitochondria. Am J Physiol Cell Physiol. 2002 May;282(5):C1031-41. (
  • Miyazaki E, Sakaguchi M, Wakabayashi S, Shigekawa M, Mihara K. NHE6 protein possesses a signal peptide destined for endoplasmic reticulum membrane and localizes in secretory organelles of the cell. J Biol Chem. 2001 Dec 28;276(52):49221-7. Epub 2001 Oct 18. (
  • Nakamura N, Tanaka S, Teko Y, Mitsui K, Kanazawa H. Four Na+/H+ exchanger isoforms are distributed to Golgi and post-Golgi compartments and are involved in organelle pH regulation. J Biol Chem. 2005 Jan 14;280(2):1561-72. Epub 2004 Nov 2. (
  • NCBI Gene (
  • Ohgaki R, van IJzendoorn SC, Matsushita M, Hoekstra D, Kanazawa H. Organellar Na+/H+ exchangers: novel players in organelle pH regulation and their emerging functions. Biochemistry. 2011 Feb 1;50(4):443-50. doi: 10.1021/bi101082e. Epub 2010 Dec 30. Review. (
  • Park M, Salgado JM, Ostroff L, Helton TD, Robinson CG, Harris KM, Ehlers MD. Plasticity-induced growth of dendritic spines by exocytic trafficking from recycling endosomes. Neuron. 2006 Dec 7;52(5):817-30. (


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: April 2012
Published: February 1, 2016