OTX2

Reviewed March 2010

What is the official name of the OTX2 gene?

The official name of this gene is “orthodenticle homeobox 2.”

OTX2 is the gene's official symbol. The OTX2 gene is also known by other names, listed below.

What is the normal function of the OTX2 gene?

The OTX2 gene provides instructions for producing a protein that regulates the activity of other genes. On the basis of this action, the OTX2 protein is called a transcription factor. The OTX2 gene is part of a family of homeobox genes, which act during early embryonic development to control the formation of many body structures.

The OTX2 gene plays a critical role in the development of the eyes and related structures, such as the nerves that carry visual information from the eyes to the brain (optic nerves). It is also involved in brain development, including the formation of the pituitary gland at the base of the brain. The pituitary gland produces hormones that help control growth, reproduction, and other critical body functions.

Does the OTX2 gene share characteristics with other genes?

The OTX2 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? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.

How are changes in the OTX2 gene related to health conditions?

septo-optic dysplasia - caused by mutations in the OTX2 gene

At least eight mutations in the OTX2 gene have been identified in people with the major features of septo-optic dysplasia. Some of these mutations prevent the production of a functional OTX2 protein. Other mutations lead to a defective version of the protein that cannot regulate the activity of other genes.

A shortage of the OTX2 protein disrupts the formation and early development of the eyes, the optic nerves, the pituitary gland, and other brain structures. These problems with development lead to the major features of septo-optic dysplasia, including eye abnormalities, underdevelopment of the pituitary gland (pituitary hypoplasia), and learning difficulties. However, the signs and symptoms associated with OTX2 gene mutations vary widely, even among affected members of the same family. Additional features that have been reported in people with OTX2 gene mutations include delayed development, slow growth, and seizures.

Studies suggest that mutations in the OTX2 gene are a rare cause of septo-optic dysplasia.

Where is the OTX2 gene located?

Cytogenetic Location: 14q22.3

Molecular Location on chromosome 14: base pairs 57,267,424 to 57,277,193

The OTX2 gene is located on the long (q) arm of chromosome 14 at position 22.3.

More precisely, the OTX2 gene is located from base pair 57,267,424 to base pair 57,277,193 on chromosome 14.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about OTX2?

You and your healthcare professional may find the following resources about OTX2 helpful.

Educational resources - Information pages
Endocrinology: An Integrated Approach (first edition, 2001): The Pituitary Gland (http://www.ncbi.nlm.nih.gov/books/NBK27/)
Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=anophthalmia-ov)
Genetic Testing Registry - Repository of genetic test information
- GTR: Genetic tests for OTX2 (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=5015%5Bgeneid%5D)

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

PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/pubmed?term=(OTX2%5BTIAB%5D)%20AND%20((Genes%5BMH%5D)%20OR%20(Genetic%20Phenomena%5BMH%5D))%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%201800%20days%22%5Bdp%5D)
OMIM - Genetic disorder catalog (http://omim.org/entry/600037)
Research Resources - Tools for researchers
- Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://atlasgeneticsoncology.org/Genes/GC_OTX2.html)
- Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/5015)
- GeneCards (http://www.genecards.org/cgi-bin/carddisp.pl?id_type=entrezgene&id=5015)
- HUGO Gene Nomenclature Committee (http://www.genenames.org/data/hgnc_data.php?hgnc_id=8522)

What other names do people use for the OTX2 gene or gene products?

homeobox protein OTX2
MCOPS5
MGC45000
orthodenticle homolog 2
OTX2_HUMAN

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding OTX2?

deficiency ; dysplasia ; embryonic ; gene ; homeobox ; hormone ; hypoplasia ; pituitary gland ; protein ; reproduction ; transcription ; transcription factor

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

Dateki S, Fukami M, Sato N, Muroya K, Adachi M, Ogata T. OTX2 mutation in a patient with anophthalmia, short stature, and partial growth hormone deficiency: functional studies using the IRBP, HESX1, and POU1F1 promoters. J Clin Endocrinol Metab. 2008 Oct;93(10):3697-702. doi: 10.1210/jc.2008-0720. Epub 2008 Jul 15. (http://www.ncbi.nlm.nih.gov/pubmed/18628516?dopt=Abstract)
Dateki S, Kosaka K, Hasegawa K, Tanaka H, Azuma N, Yokoya S, Muroya K, Adachi M, Tajima T, Motomura K, Kinoshita E, Moriuchi H, Sato N, Fukami M, Ogata T. Heterozygous orthodenticle homeobox 2 mutations are associated with variable pituitary phenotype. J Clin Endocrinol Metab. 2010 Feb;95(2):756-64. doi: 10.1210/jc.2009-1334. Epub 2009 Dec 4. (http://www.ncbi.nlm.nih.gov/pubmed/19965921?dopt=Abstract)
Diaczok D, Romero C, Zunich J, Marshall I, Radovick S. A novel dominant negative mutation of OTX2 associated with combined pituitary hormone deficiency. J Clin Endocrinol Metab. 2008 Nov;93(11):4351-9. doi: 10.1210/jc.2008-1189. Epub 2008 Aug 26. (http://www.ncbi.nlm.nih.gov/pubmed/18728160?dopt=Abstract)
Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/5015)
Ragge NK, Brown AG, Poloschek CM, Lorenz B, Henderson RA, Clarke MP, Russell-Eggitt I, Fielder A, Gerrelli D, Martinez-Barbera JP, Ruddle P, Hurst J, Collin JR, Salt A, Cooper ST, Thompson PJ, Sisodiya SM, Williamson KA, Fitzpatrick DR, van Heyningen V, Hanson IM. Heterozygous mutations of OTX2 cause severe ocular malformations. Am J Hum Genet. 2005 Jun;76(6):1008-22. Epub 2005 Apr 21. Erratum in: Am J Hum Genet. 2005 Aug;77(2):334. (http://www.ncbi.nlm.nih.gov/pubmed/15846561?dopt=Abstract)
Tajima T, Ohtake A, Hoshino M, Amemiya S, Sasaki N, Ishizu K, Fujieda K. OTX2 loss of function mutation causes anophthalmia and combined pituitary hormone deficiency with a small anterior and ectopic posterior pituitary. J Clin Endocrinol Metab. 2009 Jan;94(1):314-9. doi: 10.1210/jc.2008-1219. Epub 2008 Oct 14. (http://www.ncbi.nlm.nih.gov/pubmed/18854396?dopt=Abstract)
Wyatt A, Bakrania P, Bunyan DJ, Osborne RJ, Crolla JA, Salt A, Ayuso C, Newbury-Ecob R, Abou-Rayyah Y, Collin JR, Robinson D, Ragge N. Novel heterozygous OTX2 mutations and whole gene deletions in anophthalmia, microphthalmia and coloboma. Hum Mutat. 2008 Nov;29(11):E278-83. doi: 10.1002/humu.20869. (http://www.ncbi.nlm.nih.gov/pubmed/18781617?dopt=Abstract)

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.



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