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SLC52A3 gene

solute carrier family 52 member 3

Normal Function

The SLC52A3 gene (previously called the C20orf54 gene) provides instructions for making a riboflavin transporter protein called RFVT3 (formerly known as RFT2). This protein moves (transports) a vitamin called riboflavin (also called 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 RFVT3 protein is found at especially high levels in cells of the small intestine and is important for absorbing riboflavin during digestion so that the vitamin can be used in the body.

In the cells of 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.

Health Conditions Related to Genetic Changes

Riboflavin transporter deficiency neuronopathy

More than two dozen mutations in the SLC52A3 gene have been found to cause riboflavin transporter deficiency neuronopathy. This neurological condition encompasses two disorders that were previously considered to be separate: Brown-Vialetto-Van Laere syndrome and Fazio-Londe disease. The gene mutations involved in this condition lead to production of abnormal RFVT3 proteins. Some mutations lead to the production of an altered protein that cannot get to the cell membrane, so it is unable to transport riboflavin into the cell. Other mutations lead to a version of the protein that can get to the cell membrane, but its function as a transporter is impaired. These changes impair the absorption of riboflavin in the small intestine. The resulting shortage of riboflavin leads to a reduction of FAD and FMN. However, it is unclear how these changes lead to the nerve problems that cause hearing loss, muscle weakness in the face and limbs, and breathing problems in people with the disorder.

More About This Health Condition

Other Names for This Gene

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

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Gene and Variant Databases


  • 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. Citation on PubMed or Free article on PubMed Central
  • Cali E, Dominik N, Manole A, Houlden H. Riboflavin Transporter Deficiency. 2015 Jun 11 [updated 2021 Apr 8]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from Citation on PubMed
  • 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. doi: 10.1016/j.braindev.2004.10.003. Epub 2004 Dec 15. Citation on PubMed
  • 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. Citation on PubMed or Free article on PubMed Central
  • 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. doi: 10.1093/brain/115.6.1889. Citation on PubMed
  • 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. Citation on PubMed or Free article on PubMed Central
  • 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. Citation on PubMed or Free article on PubMed Central
  • Yonezawa A, Inui K. Novel riboflavin transporter family RFVT/SLC52: identification, nomenclature, functional characterization and genetic diseases of RFVT/SLC52. Mol Aspects Med. 2013 Apr-Jun;34(2-3):693-701. doi: 10.1016/j.mam.2012.07.014. Citation on PubMed

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.