VKORC1

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What is the official name of the VKORC1 gene?

The official name of this gene is “vitamin K epoxide reductase complex, subunit 1.”

VKORC1 is the gene's official symbol. The VKORC1 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 VKORC1 gene?

The VKORC1 gene provides instructions for making one piece (subunit) of the vitamin K epoxide reductase (VKOR) complex. The VKOR enzyme complex is made primarily in the liver. It spans the membrane of a cellular structure called the endoplasmic reticulum, which is involved with protein processing and transport. The VKOR complex helps turn on (activate) clotting proteins in the pathway that forms blood clots. Specifically, the VKOR complex converts one form of vitamin K into a different form of vitamin K that assists in activating clotting proteins.

How are changes in the VKORC1 gene related to health conditions?

warfarin sensitivity - associated with the VKORC1 gene: Multiple variations (polymorphisms) in the VKORC1 gene have been associated with warfarin sensitivity, a condition in which individuals require lower doses of the drug warfarin than are usually prescribed. Warfarin is a blood thinner, which means that it prevents blood clots from forming. It acts by preventing (inhibiting) the action of the VKOR complex and stopping the activation of the clotting proteins.
The most common VKORC1 gene polymorphism in people with warfarin sensitivity, known asVKORC1A, changes a single DNA building block (nucleotide) in an area near the VKORC1gene, which controls the production of the subunit. Specifically, the nucleotide guanine is replaced with the nucleotide adenine (written as -1639G>A). The VKORC1A polymorphism is particularly common in individuals of Asian and European descent. The gene change causes less of the subunit to be produced and reduces the amount of VKOR complex that is available to convert vitamin K into a form that can help activate clotting proteins. Because there is a decreased amount of VKOR complex, less warfarin is needed to inhibit the actions of the complex, resulting in warfarin sensitivity. If people with warfarin sensitivity take the average dose (or more) of warfarin, they are at risk of an overdose, which can cause abnormal bleeding in the brain, gastrointestinal tract, or other tissues, and may lead to serious health problems or death.

Where is the VKORC1 gene located?

Cytogenetic Location: 16p11.2

Molecular Location on chromosome 16: base pairs 31,090,853 to 31,096,336

The VKORC1 gene is located on the short (p) arm of chromosome 16 at position 11.2.

More precisely, the VKORC1 gene is located from base pair 31,090,853 to base pair 31,096,336 on chromosome 16.

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

Where can I find additional information about VKORC1?

You and your healthcare professional may find the following resources about VKORC1 helpful.

Educational resources - Information pages
Biochemistry (fifth edition, 2002): Blood-Clotting Cascade
Genetic Testing Registry - Repository of genetic test information (1 link)

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

PubMed - Recent literature
OMIM - Genetic disorder catalog
Research Resources - Tools for researchers (3 links)

What other names do people use for the VKORC1 gene or gene products?

FLJ00289
vitamin K 1 2,3-epoxide reductase subunit 1
vitamin K epoxide reductase complex subunit 1
VKOR

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

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 VKORC1?

adenine ; blood thinner ; clotting ; DNA ; endoplasmic reticulum ; enzyme ; gastrointestinal ; gene ;guanine ; nucleotide ; pharmacogenetics ; pharmacogenomics ; polymorphism ; protein ; sensitivity ;subunit ; warfarin

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

References (7 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