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

TBX gene family

Reviewed December 2009

What are the TBX genes?

Genes in the TBX gene family provide instructions for making proteins called T-box proteins that play critical roles during embryonic development. These proteins are especially important for normal development of the arms, hands, and heart. T-box proteins regulate the activity of other genes by attaching (binding) to specific regions of DNA. On the basis of this action, T-box proteins are called transcription factors. Genes in the T-box family are grouped together because the proteins produced from these genes share a similar segment called a T box. The T box is the part of the protein that binds to DNA. T-box proteins often interact with one another or with other transcription factors that regulate gene activity.

Researchers have identified at least 17 genes in the TBX gene family. Mutations in these genes lead to disorders that involve the abnormal development of tissues in which a particular T-box gene is active (expressed). Many genetic disorders caused by T-box gene mutations are characterized by heart problems and/or skeletal abnormalities of the hands and arms.

Which genes are included in the TBX gene family?

The HUGO Gene Nomenclature Committee (HGNC) provides an index of gene families ( and their member genes.

Genetics Home Reference summarizes the normal function and health implications of these members of the TBX gene family: T, TBX1, and TBX5.

What conditions are related to genes in the TBX gene family?

Genetics Home Reference includes these conditions related to genes in the TBX gene family:

  • 22q11.2 deletion syndrome
  • chordoma
  • Holt-Oram syndrome

Where can I find additional information about the TBX gene family?

You may find the following resources about the TBX gene family helpful.

  • Developmental Biology (sixth edition, 2000): Specification of Forelimb or Hindlimb: Tbx4 and Tbx5 ( (U.S. National Library of Medicine)

What glossary definitions help with understanding the TBX gene family?

DNA ; embryonic ; expressed ; gene ; protein ; transcription ; transcription factor

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


These sources were used to develop the Genetics Home Reference summary for the TBX gene family.

  • Hoogaars WM, Barnett P, Moorman AF, Christoffels VM. T-box factors determine cardiac design. Cell Mol Life Sci. 2007 Mar;64(6):646-60. Review. (
  • King M, Arnold JS, Shanske A, Morrow BE. T-genes and limb bud development. Am J Med Genet A. 2006 Jul 1;140(13):1407-13. Review. (
  • Hatcher CJ, Basson CT. Specification of the cardiac conduction system by transcription factors. Circ Res. 2009 Sep 25;105(7):620-30. doi: 10.1161/CIRCRESAHA.109.204123. Review. (
  • Yutzey KE. Teed off: cardiac conduction system development requires T-box transcription factors. Circ Res. 2008 Jun 6;102(11):1295-7. doi: 10.1161/CIRCRESAHA.108.178061. (


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: December 2009
Published: February 8, 2016