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Reviewed May 2010
What is the official name of the FXN gene?
The official name of this gene is “frataxin.”
FXN is the gene's official symbol. The FXN 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 FXN gene?
The FXN gene provides instructions for making a protein called frataxin. This protein is found in cells throughout the body, with the highest levels in the heart, spinal cord, liver, pancreas, and muscles used for voluntary movement (skeletal muscles). Within cells, frataxin is found in energy-producing structures called mitochondria. Although its function is not fully understood, frataxin appears to help assemble clusters of iron and sulfur molecules that are critical for the function of many proteins, including those needed for energy production.
One region of the FXN gene contains a segment of DNA known as a GAA trinucleotide repeat. This segment is made up of a series of three DNA building blocks (one guanine and two adenines) that appear multiple times in a row. In most people, the number of GAA repeats in the FXN gene is fewer than 12 (referred to as short normal). Sometimes, however, the GAA segment is repeated 12 to 33 times (referred to as long normal).
How are changes in the FXN gene related to health conditions?
Where is the FXN gene located?
Cytogenetic Location: 9q21.11
Molecular Location on chromosome 9: base pairs 69,035,563 to 69,100,178
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The FXN gene is located on the long (q) arm of chromosome 9 at position 21.11.
More precisely, the FXN gene is located from base pair 69,035,563 to base pair 69,100,178 on chromosome 9.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about FXN?
You and your healthcare professional may find the following resources about FXN 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 FXN gene or gene products?
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 FXN?
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (11 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.