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STXBP1 gene

syntaxin binding protein 1
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Normal Function

The STXBP1 gene provides instructions for making syntaxin-binding protein 1. In nerve cells (neurons), this protein helps regulate the release of chemical messengers called neurotransmitters from compartments known as synaptic vesicles. The release of neurotransmitters relays signals between neurons and is critical for normal brain function.

To release its neurotransmitters, a synaptic vesicle must join (fuse) with the outer membrane of the neuron. The syntaxin-binding protein 1 regulates the formation of a group (complex) of proteins that allows vesicle fusion.

Health Conditions Related to Genetic Changes

STXBP1 encephalopathy with epilepsy

At least 85 mutations in the STXBP1 gene have been found to cause STXBP1 encephalopathy with epilepsy. This condition is characterized by recurrent seizures (epilepsy) that begin in infancy, abnormal brain function (encephalopathy), and intellectual disability. The mutations can alter the structure of the syntaxin-binding protein 1, result in an abnormally short protein, or add or delete small sections of the protein.

The gene mutations that cause STXBP1 encephalopathy with epilepsy reduce the amount of functional syntaxin-binding protein 1 produced from the gene. A shortage of this protein impairs the formation of the protein complex that allows vesicle fusion and the release of neurotransmitters from neurons. A change in neurotransmitter levels can lead to uncontrolled activation (excitation) of neurons, which causes seizures. This altered neuronal activity does not appear to impair the development or survival of neurons; the cause of the encephalopathy and other neurological problems in this condition is unclear.

More About This Health Condition

Lennox-Gastaut syndrome

MedlinePlus Genetics provides information about Lennox-Gastaut syndrome

More About This Health Condition

Other disorders

At least three mutations in the STXBP1 gene have been found to cause a condition characterized by difficulty coordinating movements (ataxia), involuntary trembling (tremors), intellectual disability, and developmental delay. Unlike, STXBP1 encephalopathy with epilepsy (described above), individuals with this condition do not develop seizures. It is unclear why STXBP1 gene mutations cause seizures in some individuals and not in others.

Other Names for This Gene

  • hUNC18
  • MUNC18-1
  • N-Sec1
  • neuronal SEC1
  • NSEC1
  • RBSEC1
  • unc-18A
  • UNC18
  • unc18-1

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Research Resources


  • Di Meglio C, Lesca G, Villeneuve N, Lacoste C, Abidi A, Cacciagli P, Altuzarra C, Roubertie A, Afenjar A, Renaldo-Robin F, Isidor B, Gautier A, Husson M, Cances C, Metreau J, Laroche C, Chouchane M, Ville D, Marignier S, Rougeot C, Lebrun M, de Saint Martin A, Perez A, Riquet A, Badens C, Missirian C, Philip N, Chabrol B, Villard L, Milh M. Epileptic patients with de novo STXBP1 mutations: Key clinical features based on 24 cases. Epilepsia. 2015 Dec;56(12):1931-40. doi: 10.1111/epi.13214. Epub 2015 Oct 29. Citation on PubMed
  • Gburek-Augustat J, Beck-Woedl S, Tzschach A, Bauer P, Schoening M, Riess A. Epilepsy is not a mandatory feature of STXBP1 associated ataxia-tremor-retardation syndrome. Eur J Paediatr Neurol. 2016 Jul;20(4):661-5. doi: 10.1016/j.ejpn.2016.04.005. Epub 2016 Apr 28. Citation on PubMed
  • Patzke C, Han Y, Covy J, Yi F, Maxeiner S, Wernig M, Südhof TC. Analysis of conditional heterozygous STXBP1 mutations in human neurons. J Clin Invest. 2015 Sep;125(9):3560-71. doi: 10.1172/JCI78612. Epub 2015 Aug 17. Citation on PubMed or Free article on PubMed Central
  • Rizo J, Rosenmund C. Synaptic vesicle fusion. Nat Struct Mol Biol. 2008 Jul;15(7):665-74. Review. Citation on PubMed or Free article on PubMed Central
  • Stamberger H, Nikanorova M, Willemsen MH, Accorsi P, Angriman M, Baier H, Benkel-Herrenbrueck I, Benoit V, Budetta M, Caliebe A, Cantalupo G, Capovilla G, Casara G, Courage C, Deprez M, Destrée A, Dilena R, Erasmus CE, Fannemel M, Fjær R, Giordano L, Helbig KL, Heyne HO, Klepper J, Kluger GJ, Lederer D, Lodi M, Maier O, Merkenschlager A, Michelberger N, Minetti C, Muhle H, Phalin J, Ramsey K, Romeo A, Schallner J, Schanze I, Shinawi M, Sleegers K, Sterbova K, Syrbe S, Traverso M, Tzschach A, Uldall P, Van Coster R, Verhelst H, Viri M, Winter S, Wolff M, Zenker M, Zoccante L, De Jonghe P, Helbig I, Striano P, Lemke JR, Møller RS, Weckhuysen S. STXBP1 encephalopathy: A neurodevelopmental disorder including epilepsy. Neurology. 2016 Mar 8;86(10):954-62. doi: 10.1212/WNL.0000000000002457. Epub 2016 Feb 10. Review. Citation on PubMed
  • Yamamoto T, Shimojima K, Yano T, Ueda Y, Takayama R, Ikeda H, Imai K. Loss-of-function mutations of STXBP1 in patients with epileptic encephalopathy. Brain Dev. 2016 Mar;38(3):280-4. doi: 10.1016/j.braindev.2015.09.004. Epub 2015 Sep 16. Citation on PubMed
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