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TBP gene

TATA-box binding protein

Normal Function

The TBP gene provides instructions for making a protein called the TATA-box binding protein. This protein is active in cells and tissues throughout the body, where it plays an essential role in regulating the activity of most genes.

The TATA-box binding protein attaches (binds) to a particular sequence of DNA known as the TATA box. This sequence occurs in a regulatory region of DNA near the beginning of many genes. Once the protein is attached to the TATA box near a gene, it acts as a landmark to indicate where other enzymes should start reading the gene. The process of reading a gene's DNA and transferring the information to a similar molecule called messenger RNA (mRNA) is known as transcription.

One region of the TBP gene contains a particular DNA segment known as a CAG/CAA trinucleotide repeat. This segment is made up of a series of three DNA building blocks (nucleotides) that appear multiple times in a row. Normally, the CAG/CAA segment is repeated 25 to 40 times within the gene.

Health Conditions Related to Genetic Changes

Huntington's disease-like

A particular type of variant (also called a mutation) in the TBP gene has been found to cause a condition called Huntington's disease-like 4 (HDL4). The signs and symptoms of HDL4 closely resemble those of a more common condition called Huntington's disease. These signs and symptoms include uncontrolled movements, emotional problems, and a loss of thinking ability. HDL4 is sometimes known as spinocerebellar ataxia 17 (SCA17). This diagnosis is typically used when the main signs and symptoms involve difficulties with coordination and movement.

The variants associated with HDL4 and SCA17 increase the size of the CAG/CAA trinucleotide repeat in the TBP gene. Generally, individuals with 41 or more CAG/CAA repeats can develop features of HDL4 or SCA17 in their lifetimes. People with larger repeats are more likely to develop signs and symptoms of these disorders.

An increased number of CAG/CAA repeats in the TBP gene leads to the production of an abnormally long version of the TATA-box binding protein. The abnormal protein builds up in nerve cells (neurons) in the brain and disrupts the normal functions of these cells. The dysfunction and eventual death of neurons in certain areas of the brain cause the signs and symptoms of HDL4 and SCA17. Because the TBP gene is active throughout the body, it is unclear why the effects of variants in this gene are limited to the brain.

More About This Health Condition

Other Names for This Gene

  • GTF2D
  • TAF2A
  • TAFII250
  • TATA-Box Factor
  • TF2D

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Bauer P, Laccone F, Rolfs A, Wullner U, Bosch S, Peters H, Liebscher S, Scheible M, Epplen JT, Weber BH, Holinski-Feder E, Weirich-Schwaiger H, Morris-Rosendahl DJ, Andrich J, Riess O. Trinucleotide repeat expansion in SCA17/TBP in white patients with Huntington's disease-like phenotype. J Med Genet. 2004 Mar;41(3):230-2. doi: 10.1136/jmg.2003.015602. No abstract available. Citation on PubMed or Free article on PubMed Central
  • Gao R, Matsuura T, Coolbaugh M, Zuhlke C, Nakamura K, Rasmussen A, Siciliano MJ, Ashizawa T, Lin X. Instability of expanded CAG/CAA repeats in spinocerebellar ataxia type 17. Eur J Hum Genet. 2008 Feb;16(2):215-22. doi: 10.1038/sj.ejhg.5201954. Epub 2007 Nov 28. Citation on PubMed
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  • Rasmussen A, De Biase I, Fragoso-Benitez M, Macias-Flores MA, Yescas P, Ochoa A, Ashizawa T, Alonso ME, Bidichandani SI. Anticipation and intergenerational repeat instability in spinocerebellar ataxia type 17. Ann Neurol. 2007 Jun;61(6):607-10. doi: 10.1002/ana.21139. Citation on PubMed
  • Rolfs A, Koeppen AH, Bauer I, Bauer P, Buhlmann S, Topka H, Schols L, Riess O. Clinical features and neuropathology of autosomal dominant spinocerebellar ataxia (SCA17). Ann Neurol. 2003 Sep;54(3):367-75. doi: 10.1002/ana.10676. Citation on PubMed
  • Schneider SA, van de Warrenburg BP, Hughes TD, Davis M, Sweeney M, Wood N, Quinn NP, Bhatia KP. Phenotypic homogeneity of the Huntington disease-like presentation in a SCA17 family. Neurology. 2006 Nov 14;67(9):1701-3. doi: 10.1212/01.wnl.0000242740.01273.00. Citation on PubMed
  • van Roon-Mom WM, Reid SJ, Faull RL, Snell RG. TATA-binding protein in neurodegenerative disease. Neuroscience. 2005;133(4):863-72. doi: 10.1016/j.neuroscience.2005.03.024. Citation on PubMed
  • Zuhlke C, Hellenbroich Y, Dalski A, Kononowa N, Hagenah J, Vieregge P, Riess O, Klein C, Schwinger E. Different types of repeat expansion in the TATA-binding protein gene are associated with a new form of inherited ataxia. Eur J Hum Genet. 2001 Mar;9(3):160-4. doi: 10.1038/sj.ejhg.5200617. Citation on PubMed

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.