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Reviewed May 2010

What is the official name of the TOR1A gene?

The official name of this gene is “torsin family 1 member A.”

TOR1A is the gene's official symbol. The TOR1A gene is also known by other names, listed below.

Read more about gene names and symbols on the About page.

What is the normal function of the TOR1A gene?

The TOR1A gene (also known as DYT1) provides instructions for making a protein called torsinA. This protein is found in the space between two neighboring structures within cells, the nuclear envelope and the endoplasmic reticulum. The nuclear envelope surrounds the nucleus and separates it from the rest of the cell. The endoplasmic reticulum processes proteins and other molecules and helps transport them to specific destinations either inside or outside the cell. Although little is known about the function of torsinA, studies suggest that it may help process and transport other proteins. TorsinA may also participate in the movement of membranes associated with the nuclear envelope and endoplasmic reticulum.

TorsinA is active in many of the body's tissues, and it is particularly important for the normal function of nerve cells in the brain. For example, researchers have found high levels of torsinA in a part of the brain called the substantia nigra. This region contains nerve cells that produce dopamine, a chemical messenger that transmits signals within the brain to produce smooth physical movements.

How are changes in the TOR1A gene related to health conditions?

early-onset primary dystonia - caused by mutations in the TOR1A gene

A particular mutation in the TOR1A gene causes most cases of early-onset primary dystonia. This mutation, which is often called the GAG deletion or delta GAG, deletes three DNA building blocks (base pairs) from the TOR1A gene. The resulting torsinA protein is missing one protein building block (amino acid) in a critical region. The altered protein's effect on the function of nerve cells in the brain is unclear. People with early-onset primary dystonia do not have a loss of nerve cells or obvious changes in the structure of the brain that would explain the abnormal muscle contractions seen with this condition. Instead, the altered torsinA protein may have subtle effects on the connections between nerve cells and likely disrupts chemical signaling between nerve cells that control movement. Researchers are working to determine how a change in this protein leads to the characteristic features of this disorder.

benign essential blepharospasm - associated with the TOR1A gene

Several studies have examined a possible relationship between common variations (polymorphisms) in the TOR1A gene and several forms of adult-onset dystonia, including benign essential blepharospasm. The results of these studies have been mixed. Some research has suggested that certain polymorphisms increase a person's risk of developing benign essential blepharospasm. However, other studies have found no connection between changes in the TOR1A gene and risk of this disorder. Researchers are still working to clarify whether variants of the TOR1A gene are related to benign essential blepharospasm and other adult-onset dystonias.

Where is the TOR1A gene located?

Cytogenetic Location: 9q34

Molecular Location on chromosome 9: base pairs 129,812,942 to 129,824,245

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBIThis link leads to a site outside Genetics Home Reference.)

The TOR1A gene is located on the long (q) arm of chromosome 9 at position 34.

The TOR1A gene is located on the long (q) arm of chromosome 9 at position 34.

More precisely, the TOR1A gene is located from base pair 129,812,942 to base pair 129,824,245 on chromosome 9.

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

Where can I find additional information about TOR1A?

You and your healthcare professional may find the following resources about TOR1A 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 TOR1A gene or gene products?

  • DQ2
  • Dystonia 1 protein
  • dystonia 1, torsion (autosomal dominant; torsinA)
  • DYT1
  • Torsin-1A
  • torsinA
  • torsin family 1, member A (torsin A)

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding TOR1A?

amino acid ; autosomal ; autosomal dominant ; benign ; cell ; chaperone ; critical region ; deletion ; DNA ; dopamine ; dystonia ; endoplasmic reticulum ; gene ; mutation ; neuron ; nuclear envelope ; nucleus ; protein ; substantia nigra

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

See also Understanding Medical Terminology.

References (12 links)


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: May 2010
Published: February 8, 2016