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

TTC gene family

Reviewed October 2013

What are the TTC genes?

The tetratricopeptide (TTC) repeat domain containing family includes genes that provide instructions for proteins containing regions (domains) of repeating sequences called tetratricopeptides. These regions are known as tetratricopeptide repeats or TPR domains.

Within a protein, a TPR domain takes the shape of a large spiral (superhelix) with each strand made up of smaller coils. The large surface area of this structure enables proteins with TPR domains to serve as scaffolds upon which protein complexes can be built and other biochemical interactions can take place.

Proteins with TPR domains are involved in many processes in the body, such as protein production, protein transport, and the cycle of cell division. As a result, mutations in genes that belong to this family can cause many types of disorders, including developmental disorders, immune system-related diseases, and neurological problems.

Which genes are included in the TTC 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 TTC gene family: KDM6A, NCF2, SH3TC2, and TTC37.

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

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

  • Charcot-Marie-Tooth disease
  • chronic granulomatous disease
  • Kabuki syndrome
  • systemic lupus erythematosus
  • trichohepatoenteric syndrome

What glossary definitions help with understanding the TTC gene family?

cell ; cell division ; domain ; immune system ; lysine ; neurological ; protein

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 TTC gene family.

  • D'Andrea LD, Regan L. TPR proteins: the versatile helix. Trends Biochem Sci. 2003 Dec;28(12):655-62. Review. (
  • Allan RK, Ratajczak T. Versatile TPR domains accommodate different modes of target protein recognition and function. Cell Stress Chaperones. 2011 Jul;16(4):353-67. doi: 10.1007/s12192-010-0248-0. Epub 2010 Dec 9. Review. (
  • Blatch GL, Lässle M. The tetratricopeptide repeat: a structural motif mediating protein-protein interactions. Bioessays. 1999 Nov;21(11):932-9. Review. (
  • Groves MR, Barford D. Topological characteristics of helical repeat proteins. Curr Opin Struct Biol. 1999 Jun;9(3):383-9. Review. (
  • Andrade MA, Perez-Iratxeta C, Ponting CP. Protein repeats: structures, functions, and evolution. J Struct Biol. 2001 May-Jun;134(2-3):117-31. Review. (


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: October 2013
Published: February 8, 2016