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Reviewed August 2014

What is the official name of the FOXN1 gene?

The official name of this gene is “forkhead box N1.”

FOXN1 is the gene's official symbol. The FOXN1 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 FOXN1 gene?

The FOXN1 gene provides instructions for making a protein that attaches (binds) to specific regions of DNA and regulates the activity of other genes. On the basis of this action, the FOXN1 protein is called a transcription factor.

The FOXN1 protein is important for development of the skin, hair, nails, and immune system. Studies suggest that this protein helps guide the formation of hair follicles and the growth of fingernails and toenails. The FOXN1 protein also plays a critical role in the formation of the thymus, which is a gland located behind the breastbone where immune system cells called T cells mature and become functional. T cells recognize and attack foreign invaders, such as viruses and bacteria, to help prevent infection.

Researchers suspect that the FOXN1 protein is also involved in the development of the brain and spinal cord (central nervous system), although its role is unclear.

Does the FOXN1 gene share characteristics with other genes?

The FOXN1 gene belongs to a family of genes called FOX (forkhead box genes).

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 FOXN1 gene related to health conditions?

T-cell immunodeficiency, congenital alopecia, and nail dystrophy - caused by mutations in the FOXN1 gene

At least one mutation in the FOXN1 gene has been found to cause T-cell immunodeficiency, congenital alopecia, and nail dystrophy, a condition that affects the immune system and growth of the hair and nails. The known mutation, which is written as Arg255Ter or R255X, replaces the protein building block (amino acid) arginine with a signal to stop protein production. No functional FOXN1 protein is produced from the mutated gene.

A lack of FOXN1 protein prevents the formation of the thymus. When this gland is not present, the immune system cannot produce mature, functional T cells to fight infections. As a result, people with T-cell immunodeficiency, congenital alopecia, and nail dystrophy develop recurrent serious infections starting early in life. Loss of the FOXN1 protein also prevents the formation of hair follicles, leading to an absence of hair (alopecia). In addition, a shortage of this protein causes malformations of the fingernails and toenails (nail dystrophy).

Researchers have described abnormalities of the central nervous system in at least two cases of T-cell immunodeficiency, congenital alopecia, and nail dystrophy. However, it is not yet known whether central nervous system abnormalities are a common feature of this condition. It is unclear how a shortage of the FOXN1 protein might contribute to these abnormalities.

Where is the FOXN1 gene located?

Cytogenetic Location: 17q11.2

Molecular Location on chromosome 17: base pairs 28,506,229 to 28,538,900

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

The FOXN1 gene is located on the long (q) arm of chromosome 17 at position 11.2.

The FOXN1 gene is located on the long (q) arm of chromosome 17 at position 11.2.

More precisely, the FOXN1 gene is located from base pair 28,506,229 to base pair 28,538,900 on chromosome 17.

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

Where can I find additional information about FOXN1?

You and your healthcare professional may find the following resources about FOXN1 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 FOXN1 gene or gene products?

  • FKHL20
  • forkhead box protein N1
  • RONU
  • Rowett nude
  • WHN
  • winged helix nude
  • winged-helix nude
  • winged-helix transcription factor nude

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 FOXN1?

alopecia ; amino acid ; arginine ; bacteria ; cell ; central nervous system ; congenital ; DNA ; gene ; immune system ; immunodeficiency ; infection ; mutation ; nervous system ; protein ; thymus ; transcription ; transcription factor

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

See also Understanding Medical Terminology.

References (8 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: August 2014
Published: February 8, 2016