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

IFT gene family

Reviewed July 2008

What are the IFT genes?

Genes in the intraflagellar transport homolog (IFT) family provide instructions for making proteins that are found in cell structures called cilia. Cilia are microscopic, finger-like projections that stick out from the surface of cells. They are involved in cell movement and many different chemical signaling pathways. Cilia also play an important role in the perception of sensory input (such as sight, hearing, and smell).

The movement of substances within cilia and similar structures called flagella is known as intraflagellar transport. This process is essential for the assembly and maintenance of these cell structures. During intraflagellar transport, cells use molecules called IFT particles to carry materials to and from the tips of cilia. IFT particles are made of proteins produced from genes in the IFT family. Each IFT particle is made up of two groups of IFT proteins: complex A, which includes at least 6 proteins, and complex B, which includes at least 15 proteins.

The discovery of mutations in the IFT80 gene that cause asphyxiating thoracic dystrophy (also known as Jeune syndrome) was the first association of an IFT protein with a human disease.

Which genes are included in the IFT 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 IFT gene family: IFT80, IFT122, and IFT140.

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

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

  • asphyxiating thoracic dystrophy
  • cranioectodermal dysplasia
  • Mainzer-Saldino syndrome

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

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

  • WormBook: An Online Review of C. elegans Biology: Cilium biogenesis and intraflagellar transport (IFT) ( (U.S. National Library of Medicine)
  • The Cell: A Molecular Approach (second edition, 2000): Cilia and Flagella ( (U.S. National Library of Medicine)

What glossary definitions help with understanding the IFT gene family?

cell ; gene ; homologs ; perception ; protein ; syndrome

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 IFT gene family.

  • Rosenbaum JL, Witman GB. Intraflagellar transport. Nat Rev Mol Cell Biol. 2002 Nov;3(11):813-25. Review. (
  • Blacque OE, Cevik S, Kaplan OI. Intraflagellar transport: from molecular characterisation to mechanism. Front Biosci. 2008 Jan 1;13:2633-52. Review. (
  • Beales PL, Bland E, Tobin JL, Bacchelli C, Tuysuz B, Hill J, Rix S, Pearson CG, Kai M, Hartley J, Johnson C, Irving M, Elcioglu N, Winey M, Tada M, Scambler PJ. IFT80, which encodes a conserved intraflagellar transport protein, is mutated in Jeune asphyxiating thoracic dystrophy. Nat Genet. 2007 Jun;39(6):727-9. Epub 2007 Apr 29. (


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: July 2008
Published: February 1, 2016