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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed June 2012

What is the official name of the EFHC1 gene?

The official name of this gene is “EF-hand domain (C-terminal) containing 1.”

EFHC1 is the gene's official symbol. The EFHC1 gene is also known by other names, listed below.

What is the normal function of the EFHC1 gene?

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).

Does the EFHC1 gene share characteristics with other genes?

The EFHC1 gene belongs to a family of genes called EF-hand domain containing (EF-hand domain containing).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? ( in the Handbook.

How are changes in the EFHC1 gene related to health conditions?

juvenile myoclonic epilepsy - associated with the EFHC1 gene

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.

Where is the EFHC1 gene located?

Cytogenetic Location: 6p12.3

Molecular Location on chromosome 6: base pairs 52,420,196 to 52,495,785

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The EFHC1 gene is located on the short (p) arm of chromosome 6 at position 12.3.

The EFHC1 gene is located on the short (p) arm of chromosome 6 at position 12.3.

More precisely, the EFHC1 gene is located from base pair 52,420,196 to base pair 52,495,785 on chromosome 6.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about EFHC1?

You and your healthcare professional may find the following resources about EFHC1 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the EFHC1 gene or gene products?

  • EF-hand domain-containing protein 1
  • myoclonin-1

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding EFHC1?

acids ; apoptosis ; calcium ; cell ; cell membrane ; channel ; domain ; epilepsy ; gene ; homeostasis ; ions ; juvenile ; nervous system ; protein

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • 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. (
  • Medina MT, Suzuki T, Alonso ME, Durón RM, Martínez-Juárez 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. (
  • NCBI Gene (
  • 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. Epub 2004 Jul 18. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: June 2012
Published: February 1, 2016