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SPG7 gene

SPG7 matrix AAA peptidase subunit, paraplegin

Normal Function

The SPG7 gene provides instructions for producing a protein called paraplegin, which is a member of the AAA protein family. This protein family plays a role in many cellular activities, including regulation of cell components and proteins. Located within the inner membrane of the energy-producing centers of cells (mitochondria), paraplegin is one of the proteins that form a complex called the m-AAA protease. The m-AAA protease is responsible for assembling ribosomes (cellular structures that process the cell's genetic instructions to create proteins) and removing nonfunctional proteins in the mitochondria.

Health Conditions Related to Genetic Changes

Spastic paraplegia type 7

More than 100 mutations in the SPG7 gene have been found to cause spastic paraplegia type 7. This condition is characterized by muscle weakness, progressive muscle stiffness (spasticity) in the legs, and difficulty walking. Most of the SPG7 gene mutations change single protein building blocks (amino acids) in the paraplegin protein. When paraplegin is altered, it cannot organize with other proteins within the mitochondria to form the m-AAA protease. The buildup of unusable proteins in nerve cells, caused by the nonfunctional m-AAA protease, can impair mitochondrial functioning and diminish nerve cell signaling, leading to the major signs and symptoms of spastic paraplegia type 7.

More About This Health Condition

Progressive external ophthalmoplegia

MedlinePlus Genetics provides information about Progressive external ophthalmoplegia

More About This Health Condition

Other Names for This Gene

  • CAR
  • cell adhesion regulator
  • CMAR
  • FLJ37308
  • MGC126331
  • MGC126332
  • paraplegin, isoform 1
  • PGN
  • spastic paraplegia 7
  • spastic paraplegia 7 (pure and complicated autosomal recessive)
  • SPG5C

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Atorino L, Silvestri L, Koppen M, Cassina L, Ballabio A, Marconi R, Langer T, Casari G. Loss of m-AAA protease in mitochondria causes complex I deficiency and increased sensitivity to oxidative stress in hereditary spastic paraplegia. J Cell Biol. 2003 Nov 24;163(4):777-87. doi: 10.1083/jcb.200304112. Epub 2003 Nov 17. Citation on PubMed or Free article on PubMed Central
  • Casari G, Marconi R. Spastic Paraplegia 7. 2006 Aug 24 [updated 2018 Oct 25]. 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
  • Coarelli G, Schule R, van de Warrenburg BPC, De Jonghe P, Ewenczyk C, Martinuzzi A, Synofzik M, Hamer EG, Baets J, Anheim M, Schols L, Deconinck T, Masrori P, Fontaine B, Klockgether T, D'Angelo MG, Monin ML, De Bleecker J, Migeotte I, Charles P, Bassi MT, Klopstock T, Mochel F, Ollagnon-Roman E, D'Hooghe M, Kamm C, Kurzwelly D, Papin M, Davoine CS, Banneau G, Tezenas du Montcel S, Seilhean D, Brice A, Duyckaerts C, Stevanin G, Durr A. Loss of paraplegin drives spasticity rather than ataxia in a cohort of 241 patients with SPG7. Neurology. 2019 Jun 4;92(23):e2679-e2690. doi: 10.1212/WNL.0000000000007606. Epub 2019 May 8. Citation on PubMed or Free article on PubMed Central
  • Patron M, Sprenger HG, Langer T. m-AAA proteases, mitochondrial calcium homeostasis and neurodegeneration. Cell Res. 2018 Mar;28(3):296-306. doi: 10.1038/cr.2018.17. Epub 2018 Feb 16. Citation on PubMed or Free article on PubMed Central
  • Settasatian C, Whitmore SA, Crawford J, Bilton RL, Cleton-Jansen AM, Sutherland GR, Callen DF. Genomic structure and expression analysis of the spastic paraplegia gene, SPG7. Hum Genet. 1999 Jul-Aug;105(1-2):139-44. doi: 10.1007/s004399900087. Citation on PubMed
  • SPG7 mutations are a common cause of undiagnosed ataxia. Neurology. 2015 May 5;84(18):1911. doi: 10.1212/WNL.0000000000001628. No abstract available. Citation on PubMed or Free article on PubMed Central
  • Wilkinson PA, Crosby AH, Turner C, Bradley LJ, Ginsberg L, Wood NW, Schapira AH, Warner TT. A clinical, genetic and biochemical study of SPG7 mutations in hereditary spastic paraplegia. Brain. 2004 May;127(Pt 5):973-80. doi: 10.1093/brain/awh125. Epub 2004 Feb 25. Erratum In: Brain. 2004 Sep;127(Pt 9):2148. Citation on PubMed

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