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


Reviewed August 2012

What is the official name of the SLC52A3 gene?

The official name of this gene is “solute carrier family 52 (riboflavin transporter), member 3.”

SLC52A3 is the gene's official symbol. The SLC52A3 gene is also known by other names, listed below.

What is the normal function of the SLC52A3 gene?

The SLC52A3 gene (previously called the C20orf54 gene) provides instructions for making the riboflavin transporter 2 (RFT2) protein. This protein transports a vitamin called riboflavin (or vitamin B2) across the cell membrane. Riboflavin cannot be made by the body, so it must be obtained from the food a person eats. The RFT2 protein is found at especially high levels in cells of the small intestine and is important for absorbing riboflavin from the small intestine after digestion so that the vitamin can be used in the body.

Riboflavin is the core component of molecules called flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN). These molecules function as coenzymes, which means they help enzymes carry out chemical reactions. FAD and FMN are involved in many different chemical reactions and are required for a variety of cellular processes. One important role of these coenzymes is in the production of energy for cells. FAD and FMN are also involved in the breakdown (metabolism) of carbohydrates, fats, and proteins.

Does the SLC52A3 gene share characteristics with other genes?

The SLC52A3 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 SLC52A3 gene related to health conditions?

Brown-Vialetto-Van Laere syndrome - caused by mutations in the SLC52A3 gene

Mutations in the SLC52A3 gene can cause Brown-Vialetto-Van Laere syndrome (BVVLS), a neurological condition characterized by nerve paralysis, hearing loss, muscle weakness, and breathing problems. The gene mutations involved in this condition lead to an abnormal RFT2 protein with impaired ability to transport riboflavin. Consequently, there is a reduction of riboflavin available in the body. However, it is unclear how these changes lead to the nerve problems characteristic of BVVLS.

other disorders - caused by mutations in the SLC52A3 gene

Mutations in the SLC52A3 gene are involved in a condition similar to Brown-Vialetto-Van Laere syndrome (BVVLS, discussed above) called Fazio-Londe disease. People with this condition have signs and symptoms similar to those of BVVLS but without hearing loss. Typically, people with Fazio-Londe disease have breathing problems, drooping eyelids (ptosis), and muscle weakness in the face and limbs, which worsen rapidly. As in BVVLS, mutations in the SLC52A3 gene that cause Fazio-Londe disease impair the absorption of riboflavin from the small intestine. Some researchers believe that these disorders are not two separate conditions; instead, they are forms of a single disorder with varying signs and symptoms.

Where is the SLC52A3 gene located?

Cytogenetic Location: 20p13

Molecular Location on chromosome 20: base pairs 760,080 to 775,985

The SLC52A3 gene is located on the short (p) arm of chromosome 20 at position 13.

The SLC52A3 gene is located on the short (p) arm of chromosome 20 at position 13.

More precisely, the SLC52A3 gene is located from base pair 760,080 to base pair 775,985 on chromosome 20.

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

Where can I find additional information about SLC52A3?

You and your healthcare professional may find the following resources about SLC52A3 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 SLC52A3 gene or gene products?

  • bA371L19.1
  • C20orf54
  • hRFT2
  • MGC10698
  • RFT2
  • RFVT3
  • riboflavin transporter 2
  • solute carrier family 52, riboflavin transporter, member 3

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

What glossary definitions help with understanding SLC52A3?

adenine ; breakdown ; carrier ; cell ; cell membrane ; digestion ; gene ; intestine ; metabolism ; neurological ; protein ; ptosis ; solute ; syndrome

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


  • Bosch AM, Abeling NG, Ijlst L, Knoester H, van der Pol WL, Stroomer AE, Wanders RJ, Visser G, Wijburg FA, Duran M, Waterham HR. Brown-Vialetto-Van Laere and Fazio Londe syndrome is associated with a riboflavin transporter defect mimicking mild MADD: a new inborn error of metabolism with potential treatment. J Inherit Metab Dis. 2011 Feb;34(1):159-64. doi: 10.1007/s10545-010-9242-z. Epub 2010 Nov 26. (
  • Dipti S, Childs AM, Livingston JH, Aggarwal AK, Miller M, Williams C, Crow YJ. Brown-Vialetto-Van Laere syndrome; variability in age at onset and disease progression highlighting the phenotypic overlap with Fazio-Londe disease. Brain Dev. 2005 Sep;27(6):443-6. Epub 2004 Dec 15. (
  • Fujimura M, Yamamoto S, Murata T, Yasujima T, Inoue K, Ohta KY, Yuasa H. Functional characteristics of the human ortholog of riboflavin transporter 2 and riboflavin-responsive expression of its rat ortholog in the small intestine indicate its involvement in riboflavin absorption. J Nutr. 2010 Oct;140(10):1722-7. doi: 10.3945/jn.110.128330. Epub 2010 Aug 19. (
  • Green P, Wiseman M, Crow YJ, Houlden H, Riphagen S, Lin JP, Raymond FL, Childs AM, Sheridan E, Edwards S, Josifova DJ. Brown-Vialetto-Van Laere syndrome, a ponto-bulbar palsy with deafness, is caused by mutations in c20orf54. Am J Hum Genet. 2010 Mar 12;86(3):485-9. doi: 10.1016/j.ajhg.2010.02.006. Epub 2010 Mar 4. (
  • McShane MA, Boyd S, Harding B, Brett EM, Wilson J. Progressive bulbar paralysis of childhood. A reappraisal of Fazio-Londe disease. Brain. 1992 Dec;115 ( Pt 6):1889-900. (
  • Nabokina SM, Subramanian VS, Said HM. Effect of clinical mutations on functionality of the human riboflavin transporter-2 (hRFT-2). Mol Genet Metab. 2012 Apr;105(4):652-7. doi: 10.1016/j.ymgme.2011.12.021. Epub 2012 Jan 5. (
  • NCBI Gene (
  • Subramanian VS, Subramanya SB, Rapp L, Marchant JS, Ma TY, Said HM. Differential expression of human riboflavin transporters -1, -2, and -3 in polarized epithelia: a key role for hRFT-2 in intestinal riboflavin uptake. Biochim Biophys Acta. 2011 Dec;1808(12):3016-21. doi: 10.1016/j.bbamem.2011.08.004. Epub 2011 Aug 11. (


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: August 2012
Published: November 23, 2015