Skip navigation

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

URL of this page:

EFHC1 gene

EF-hand domain containing 1

Normal Function

The EFHC1 gene provides instructions for making a protein called EF-hand domain containing protein 1 (EFHC1). The EFHC1 protein interacts with another protein that acts as a calcium channel, allowing positively charged calcium atoms (calcium ions) to cross the cell membrane. The movement of these ions is critical for normal signaling between nerve cells (neurons) in the brain and other parts of the nervous system. The role of the EFHC1 protein is not well understood, although it is thought to help regulate the balance of calcium ions inside the cell (calcium homeostasis). Studies also show that the EFHC1 protein may stimulate the self-destruction of cells (apoptosis).

Health Conditions Related to Genetic Changes

Juvenile myoclonic epilepsy

Mutations in the EFHC1 gene have been identified in a small number of people with juvenile myoclonic epilepsy. This condition typically begins in childhood or adolescence and causes recurrent myoclonic seizures, which are characterized by rapid, uncontrolled muscle jerks. Affected individuals can also have other types of seizures called generalized tonic-clonic seizures (or grand mal seizures) and absence seizures. Most gene mutations associated with juvenile myoclonic epilepsy replace single protein building blocks (amino acids) in the EFHC1 protein. The function of the altered protein is thought to be reduced. Although it is unclear how EFHC1 gene mutations lead to juvenile myoclonic epilepsy, researchers have suggested that a decrease in EFHC1 protein function reduces apoptosis, leading to more neurons than normal, and disrupts calcium homeostasis. Together, these changes may lead to overstimulation of the neurons, causing seizures characteristic of juvenile myoclonic epilepsy.

More About This Health Condition

Other Names for This Gene

  • EF-hand domain (C-terminal) containing 1
  • EF-hand domain-containing protein 1
  • myoclonin-1

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


  • Katano M, Numata T, Aguan K, Hara Y, Kiyonaka S, Yamamoto S, Miki T, Sawamura S, Suzuki T, Yamakawa K, Mori Y. The juvenile myoclonic epilepsy-related protein EFHC1 interacts with the redox-sensitive TRPM2 channel linked to cell death. Cell Calcium. 2012 Feb;51(2):179-85. doi: 10.1016/j.ceca.2011.12.011. Epub 2012 Jan 4. Citation on PubMed
  • Medina MT, Suzuki T, Alonso ME, Duron RM, Martinez-Juarez IE, Bailey JN, Bai D, Inoue Y, Yoshimura I, Kaneko S, Montoya MC, Ochoa A, Prado AJ, Tanaka M, Machado-Salas J, Fujimoto S, Ito M, Hamano S, Sugita K, Ueda Y, Osawa M, Oguni H, Rubio-Donnadieu F, Yamakawa K, Delgado-Escueta AV. Novel mutations in Myoclonin1/EFHC1 in sporadic and familial juvenile myoclonic epilepsy. Neurology. 2008 May 27;70(22 Pt 2):2137-44. doi: 10.1212/01.wnl.0000313149.73035.99. Citation on PubMed
  • Suzuki T, Delgado-Escueta AV, Aguan K, Alonso ME, Shi J, Hara Y, Nishida M, Numata T, Medina MT, Takeuchi T, Morita R, Bai D, Ganesh S, Sugimoto Y, Inazawa J, Bailey JN, Ochoa A, Jara-Prado A, Rasmussen A, Ramos-Peek J, Cordova S, Rubio-Donnadieu F, Inoue Y, Osawa M, Kaneko S, Oguni H, Mori Y, Yamakawa K. Mutations in EFHC1 cause juvenile myoclonic epilepsy. Nat Genet. 2004 Aug;36(8):842-9. doi: 10.1038/ng1393. Epub 2004 Jul 18. 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.