Normal Function
The TGIF1 gene provides instructions for making a protein called TG-interacting factor. This protein is important for normal development of the front part of the brain (forebrain). TG-interacting factor is a transcription factor, which means that it regulates the activity of certain genes. This protein turns off genes by attaching (binding) to specific regions of DNA or by interacting with other DNA-binding proteins.
TG-interacting factor regulates signaling pathways that are important for embryonic development. This protein blocks the signals of the transforming growth factor beta (TGF-β) pathway. This signaling pathway transmits chemical signals from the cell surface to the nucleus, which allows the environment outside the cell to affect how the cell produces other proteins. TG-interacting factor also blocks a molecule called retinoic acid from regulating gene activity. Retinoic acid, a form of vitamin A, binds to a group of transcription factors that regulate a number of genes important for early development. By blocking these signaling pathways, TG-interacting factor ensures that certain genes are turned off at the proper time.
Health Conditions Related to Genetic Changes
Nonsyndromic holoprosencephaly
At least 13 mutations in the TGIF1 gene have been found to cause nonsyndromic holoprosencephaly. This condition occurs when the brain fails to divide into two halves (hemispheres) during early development. TGIF1 gene mutations are the fourth most common cause of nonsyndromic holoprosencephaly. These mutations disrupt the protein's ability to bind with DNA or interact with other proteins. As a result, TG-interacting factor cannot block the signals of the TGF-β pathway and retinoic acid. If the signals involved in forebrain development are not properly regulated, the brain does not separate into two hemispheres. The signs and symptoms of nonsyndromic holoprosencephaly are caused by abnormal development of the brain and face.
More About This Health ConditionOther Names for This Gene
- 5'-TG-3' interacting factor
- 5'-TG-3'-interacting factor 1
- homeobox protein TGIF
- homeobox protein TGIF1
- HPE4
- MGC39747
- MGC5066
- TALE homeobox TG-interacting factor
- TGFB-induced factor homeobox 1
- TGIF
- TGIF1_HUMAN
- transforming growth factor-beta-induced factor
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
References
- Aguilella C, Dubourg C, Attia-Sobol J, Vigneron J, Blayau M, Pasquier L, Lazaro L, Odent S, David V. Molecular screening of the TGIF gene in holoprosencephaly: identification of two novel mutations. Hum Genet. 2003 Feb;112(2):131-4. doi: 10.1007/s00439-002-0862-8. Epub 2002 Nov 21. Citation on PubMed
- Dubourg C, Bendavid C, Pasquier L, Henry C, Odent S, David V. Holoprosencephaly. Orphanet J Rare Dis. 2007 Feb 2;2:8. doi: 10.1186/1750-1172-2-8. Citation on PubMed or Free article on PubMed Central
- El-Jaick KB, Powers SE, Bartholin L, Myers KR, Hahn J, Orioli IM, Ouspenskaia M, Lacbawan F, Roessler E, Wotton D, Muenke M. Functional analysis of mutations in TGIF associated with holoprosencephaly. Mol Genet Metab. 2007 Jan;90(1):97-111. doi: 10.1016/j.ymgme.2006.07.011. Epub 2006 Sep 7. Citation on PubMed or Free article on PubMed Central
- Gripp KW, Wotton D, Edwards MC, Roessler E, Ades L, Meinecke P, Richieri-Costa A, Zackai EH, Massague J, Muenke M, Elledge SJ. Mutations in TGIF cause holoprosencephaly and link NODAL signalling to human neural axis determination. Nat Genet. 2000 Jun;25(2):205-8. doi: 10.1038/76074. Citation on PubMed
- Roessler E, Muenke M. The molecular genetics of holoprosencephaly. Am J Med Genet C Semin Med Genet. 2010 Feb 15;154C(1):52-61. doi: 10.1002/ajmg.c.30236. Citation on PubMed or Free article on PubMed Central
- Solomon BD, Mercier S, Velez JI, Pineda-Alvarez DE, Wyllie A, Zhou N, Dubourg C, David V, Odent S, Roessler E, Muenke M. Analysis of genotype-phenotype correlations in human holoprosencephaly. Am J Med Genet C Semin Med Genet. 2010 Feb 15;154C(1):133-41. doi: 10.1002/ajmg.c.30240. Citation on PubMed or Free article on PubMed Central
- Tekendo-Ngongang C, Muenke M, Kruszka P. Holoprosencephaly Overview. 2000 Dec 27 [updated 2020 Mar 5]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from http://www.ncbi.nlm.nih.gov/books/NBK1530/ Citation on PubMed
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