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


Reviewed November 2006

What is the official name of the POU3F4 gene?

The official name of this gene is “POU class 3 homeobox 4.”

POU3F4 is the gene's official symbol. The POU3F4 gene is also known by other names, listed below.

What is the normal function of the POU3F4 gene?

The POU3F4 gene provides instructions for making a protein that helps regulate the activity of other genes. Based on this role, the protein is called a transcription factor. The POU3F4 gene is part of a larger family of genes called POU domain genes, all of which produce transcription factors. POU domain genes play a role in determining cell types in the central nervous system during early development. Each protein in the POU domain family has two regions, called the POU-specific domain and POU homeodomain, that bind to the DNA of other genes.

The POU3F4 gene is likely to be involved in the development of the middle and inner ear, and is also active in certain regions of the brain before birth. Researchers have not determined which genes are regulated by the POU3F4 protein.

Does the POU3F4 gene share characteristics with other genes?

The POU3F4 gene belongs to a family of genes called homeobox (homeoboxes).

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 POU3F4 gene related to health conditions?

nonsyndromic deafness - caused by mutations in the POU3F4 gene

Mutations in or near the POU3F4 gene cause a form of nonsyndromic deafness (hearing loss without related signs and symptoms affecting other parts of the body) called DFN3. This form of hearing loss usually involves abnormalities of both the inner and middle ear (mixed hearing loss). People who have surgery for this form of deafness are at high risk of a complication called a perilymphatic gusher. This complication causes a leakage of fluid from the inner ear that can result in severe dizziness and a total loss of hearing.

More than 15 POU3F4 mutations have been identified. Most of these genetic changes alter single protein building blocks (amino acids) in the POU3F4 protein or delete a small amount of genetic material from the gene. The mutations prevent cells from producing any POU3F4 protein or alter regions of the protein that are critical for binding to DNA. A lack of functional POU3F4 protein probably disrupts the normal development of structures in the middle and inner ear, leading to hearing loss.

In some cases of DFN3, mutations have been found in a section of DNA near the POU3F4 gene. Researchers believe that this region may play a role in regulating the POU3F4 gene.

Where is the POU3F4 gene located?

Cytogenetic Location: Xq21.1

Molecular Location on the X chromosome: base pairs 83,508,260 to 83,509,766

The POU3F4 gene is located on the long (q) arm of the X chromosome at position 21.1.

The POU3F4 gene is located on the long (q) arm of the X chromosome at position 21.1.

More precisely, the POU3F4 gene is located from base pair 83,508,260 to base pair 83,509,766 on the X chromosome.

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

Where can I find additional information about POU3F4?

You and your healthcare professional may find the following resources about POU3F4 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 POU3F4 gene or gene products?

  • BRAIN-4
  • Brain-specific homeobox/POU domain protein 4
  • BRN4
  • Brn-4
  • DFN3
  • DFNX2
  • OTF9
  • PO34_HUMAN

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

What glossary definitions help with understanding POU3F4?

acids ; cell ; central nervous system ; class ; complication ; DNA ; domain ; gene ; homeobox ; homeodomain ; nervous system ; protein ; surgery ; transcription ; transcription factor

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


  • Bitner-Glindzicz M, Turnpenny P, Höglund P, Kääriäinen H, Sankila EM, van der Maarel SM, de Kok YJ, Ropers HH, Cremers FP, Pembrey M, et al. Further mutations in Brain 4 (POU3F4) clarify the phenotype in the X-linked deafness, DFN3. Hum Mol Genet. 1995 Aug;4(8):1467-9. (
  • Cremers CW, Snik AF, Huygen PL, Joosten FB, Cremers FP. X-linked mixed deafness syndrome with congenital fixation of the stapedial footplate and perilymphatic gusher (DFN3). Adv Otorhinolaryngol. 2002;61:161-7. (
  • de Kok YJ, van der Maarel SM, Bitner-Glindzicz M, Huber I, Monaco AP, Malcolm S, Pembrey ME, Ropers HH, Cremers FP. Association between X-linked mixed deafness and mutations in the POU domain gene POU3F4. Science. 1995 Feb 3;267(5198):685-8. (
  • Friedman RA, Bykhovskaya Y, Tu G, Talbot JM, Wilson DF, Parnes LS, Fischel-Ghodsian N. Molecular analysis of the POU3F4 gene in patients with clinical and radiographic evidence of X-linked mixed deafness with perilymphatic gusher. Ann Otol Rhinol Laryngol. 1997 Apr;106(4):320-5. (
  • NCBI Gene (
  • Vore AP, Chang EH, Hoppe JE, Butler MG, Forrester S, Schneider MC, Smith LL, Burke DW, Campbell CA, Smith RJ. Deletion of and novel missense mutation in POU3F4 in 2 families segregating X-linked nonsyndromic deafness. Arch Otolaryngol Head Neck Surg. 2005 Dec;131(12):1057-63. (
  • Wang QJ, Li QZ, Rao SQ, Zhao YL, Yuan H, Yang WY, Han DY, Shen Y. A novel mutation of POU3F4 causes congenital profound sensorineural hearing loss in a large Chinese family. Laryngoscope. 2006 Jun;116(6):944-50. (


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: November 2006
Published: September 28, 2015