Health Topics
Normal Function
The SPART gene provides instructions for producing a protein called spartin. Spartin is found in a number of body tissues, including the brain. Research shows that spartin likely plays a role in regulating the activity of endosomes, which are structures inside the cell that are involved in sorting, transporting, and recycling proteins and other materials. Spartin may also play a role in mitochondrial function. Mitochondria are the energy-producing centers inside the cell.
Spartin is also believed to regulate the size and number of lipid droplets inside the cell. Specifically, spartin may be involved in delivering lipid droplets to the cell's recycling center. Lipid droplets help cells use and store fats, which are an important energy source. Spartin may also be involved in transporting materials from the cell surface into the cell (endocytosis).
Health Conditions Related to Genetic Changes
Troyer syndrome
Some variants (also called mutations) in the SPART gene cause Troyer syndrome. Troyer syndrome is a type of hereditary spastic paraplegia (also called hereditary spastic paraparesis), a group of conditions that cause progressive stiffness (spasticity) and weakness of the leg muscles. The first known variant associated with Troyer syndrome was found in the Old Order Amish population in Ohio. This variant deletes a single DNA building block (nucleotide) in the SPART gene. Specifically, this variant deletes the nucleotide adenosine at position 1110 in the gene. This change results in an abnormally short, nonfunctioning spartin protein. Troyer syndrome has since been diagnosed in other populations and additional variants have been found.
The variants that cause Troyer syndrome reduce the amount of functioning protein inside the cell. Cells that do not have enough normal spartin cannot break down lipid droplets properly, which allows fat molecules to build up inside the cell. This buildup of fat molecules in the cells of the brain is believed to contribute to the signs and symptoms of Troyer syndrome.
More About This Health ConditionOther Names for This Gene
- KIAA0610
- SPARTIN
- SPG20
- TAHCCP1
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
References
- Bakowska JC, Jenkins R, Pendleton J, Blackstone C. The Troyer syndrome (SPG20) protein spartin interacts with Eps15. Biochem Biophys Res Commun. 2005 Sep 9;334(4):1042-8. doi: 10.1016/j.bbrc.2005.06.201. Citation on PubMed
- Bakowska JC, Jupille H, Fatheddin P, Puertollano R, Blackstone C. Troyer syndrome protein spartin is mono-ubiquitinated and functions in EGF receptor trafficking. Mol Biol Cell. 2007 May;18(5):1683-92. doi: 10.1091/mbc.e06-09-0833. Epub 2007 Mar 1. Citation on PubMed or Free article on PubMed Central
- Baple E, Crosby A. Troyer Syndrome. 2004 Nov 16 [updated 2019 Jun 6]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from http://www.ncbi.nlm.nih.gov/books/NBK1382/ Citation on PubMed
- Butler S, Helbig KL, Alcaraz W, Seaver LH, Hsieh DT, Rohena L. Three cases of Troyer syndrome in two families of Filipino descent. Am J Med Genet A. 2016 Jul;170(7):1780-5. doi: 10.1002/ajmg.a.37658. Epub 2016 Apr 26. Citation on PubMed
- Chung J, Park J, Lai ZW, Lambert TJ, Richards RC, Zhang J, Walther TC, Farese RV Jr. The Troyer syndrome protein spartin mediates selective autophagy of lipid droplets. Nat Cell Biol. 2023 Aug;25(8):1101-1110. doi: 10.1038/s41556-023-01178-w. Epub 2023 Jul 13. Citation on PubMed
- Edwards TL, Clowes VE, Tsang HT, Connell JW, Sanderson CM, Luzio JP, Reid E. Endogenous spartin (SPG20) is recruited to endosomes and lipid droplets and interacts with the ubiquitin E3 ligases AIP4 and AIP5. Biochem J. 2009 Sep 14;423(1):31-9. doi: 10.1042/BJ20082398. Erratum In: Biochem J. 2009 Nov 1;423(3):442. Citation on PubMed
- Lu J, Rashid F, Byrne PC. The hereditary spastic paraplegia protein spartin localises to mitochondria. J Neurochem. 2006 Sep;98(6):1908-19. doi: 10.1111/j.1471-4159.2006.04008.x. Citation on PubMed
- Patel H, Cross H, Proukakis C, Hershberger R, Bork P, Ciccarelli FD, Patton MA, McKusick VA, Crosby AH. SPG20 is mutated in Troyer syndrome, an hereditary spastic paraplegia. Nat Genet. 2002 Aug;31(4):347-8. doi: 10.1038/ng937. Epub 2002 Jul 22. Citation on PubMed
- Robay D, Patel H, Simpson MA, Brown NA, Crosby AH. Endogenous spartin, mutated in hereditary spastic paraplegia, has a complex subcellular localization suggesting diverse roles in neurons. Exp Cell Res. 2006 Sep 10;312(15):2764-77. doi: 10.1016/j.yexcr.2006.05.003. Epub 2006 May 13. Citation on PubMed
- Wan N, Hong Z, Parson MAH, Korfhage JL, Burke JE, Melia TJ, Reinisch KM. Spartin-mediated lipid transfer facilitates lipid droplet turnover. Proc Natl Acad Sci U S A. 2024 Jan 16;121(3):e2314093121. doi: 10.1073/pnas.2314093121. Epub 2024 Jan 8. Citation on PubMed
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