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


Reviewed August 2008

What is the official name of the TBP gene?

The official name of this gene is “TATA box binding protein.”

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

What is the normal function of the TBP gene?

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 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 42 times within the gene.

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

Huntington disease-like syndrome - caused by mutations in the TBP gene

A particular type of mutation in the TBP gene has been found to cause a progressive brain disorder known as Huntington disease-like 4 (HDL4) or spinocerebellar ataxia type 17 (SCA17). The features of this disorder vary widely among affected individuals. The condition was first described as HDL4 in people whose signs and symptoms closely resembled those of Huntington disease, including uncontrolled movements, emotional problems, and loss of thinking ability. The disorder is now more commonly known as SCA17 because difficulty coordinating movements (ataxia) and other movement problems are the most frequent signs and symptoms. It is unknown why some people with TBP mutations have a disorder resembling Huntington disease, while others have more prominent ataxia.

The mutation associated with HDL4/SCA17 increases the size of the CAG/CAA trinucleotide repeat in the TBP gene. People with this condition have 43 to 66 CAG/CAA repeats. People with 43 to 48 CAG/CAA repeats may or may not have signs and symptoms, while people with 49 or more repeats almost always develop the disorder.

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 underlie the signs and symptoms of HDL4/SCA17. Because the TBP gene is active throughout the body, it is unclear why the effects of a mutation in this gene are limited to the brain.

Where is the TBP gene located?

Cytogenetic Location: 6q27

Molecular Location on chromosome 6: base pairs 170,554,332 to 170,572,869

The TBP gene is located on the long (q) arm of chromosome 6 at position 27.

The TBP gene is located on the long (q) arm of chromosome 6 at position 27.

More precisely, the TBP gene is located from base pair 170,554,332 to base pair 170,572,869 on chromosome 6.

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

Where can I find additional information about TBP?

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

  • CCG1 Protein
  • CCGS
  • Cell Cycle Gene 1 Protein
  • DYT3 protein, human
  • GTF2D
  • GTF2D1
  • RNA Polymerase IIA 250kD
  • RNA Polymerase II TATA-Binding Protein
  • SCA17
  • TAF1 RNA Polymerase II TATA Box Binding Protein
  • TAF2A
  • TAFII250
  • TAF(II)250
  • TATA-Binding Protein
  • TATA-Box Factor
  • TATA Sequence-Binding Protein
  • TF2D
  • Transcription Factor IID
  • Transcription Factor TBP
  • Transcription Initiation Factor TFIID 250 kDa Subunit

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

What glossary definitions help with understanding TBP?

ataxia ; cell ; cell cycle ; DNA ; gene ; molecule ; mRNA ; mutation ; promoter ; protein ; RNA ; RNA polymerase ; subunit ; syndrome ; transcription ; transcription factor ; trinucleotide repeat

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


  • Bauer P, Laccone F, Rolfs A, Wüllner U, Bösch 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. (
  • Gao R, Matsuura T, Coolbaugh M, Zühlke 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. Epub 2007 Nov 28. (
  • NCBI Gene (
  • Rasmussen A, De Biase I, Fragoso-Benítez M, Macías-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. (
  • Rolfs A, Koeppen AH, Bauer I, Bauer P, Buhlmann S, Topka H, Schöls L, Riess O. Clinical features and neuropathology of autosomal dominant spinocerebellar ataxia (SCA17). Ann Neurol. 2003 Sep;54(3):367-75. (
  • 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. (
  • van Roon-Mom WM, Reid SJ, Faull RL, Snell RG. TATA-binding protein in neurodegenerative disease. Neuroscience. 2005;133(4):863-72. Review. (
  • Zühlke 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. (


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 2008
Published: March 23, 2015