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


Reviewed November 2014

What is the official name of the TSEN54 gene?

The official name of this gene is “tRNA splicing endonuclease subunit 54.”

TSEN54 is the gene's official symbol. The TSEN54 gene is also known by other names, listed below.

What is the normal function of the TSEN54 gene?

The TSEN54 gene provides instructions for making one part (subunit) of an enzyme called the tRNA splicing endonuclease complex. This complex helps process several types of RNA molecules, which are chemical cousins of DNA.

The tRNA splicing endonuclease complex is particularly important for the normal processing of a form of RNA known as transfer RNA (tRNA). tRNA molecules help assemble protein building blocks called amino acids into full-length proteins. However, before they can assemble proteins, tRNAs must be processed into mature molecules. In particular, regions called introns need to be removed from some tRNAs for the molecules to be functional. The tRNA splicing endonuclease complex recognizes and then removes introns to help produce mature tRNA molecules.

Studies suggest that the tRNA splicing endonuclease complex may also be involved in processing another form of RNA known as messenger RNA (mRNA). mRNA serves as a genetic blueprint for making proteins. Researchers suspect that the tRNA splicing endonuclease complex cuts (cleaves) one end of mRNA molecules so a string of adenines (one of the building blocks of RNA) can be added. This process is known as polyadenylation, and the string of adenines is known as a poly(A) tail. The poly(A) tail signals the stopping point for protein production and protects mRNA from being broken down before protein production occurs.

How are changes in the TSEN54 gene related to health conditions?

pontocerebellar hypoplasia - caused by mutations in the TSEN54 gene

Several mutations in the TSEN54 gene have been identified in people with a disorder of brain development called pontocerebellar hypoplasia. The major features of this condition include delayed development, problems with movement, and intellectual disability. TSEN54 gene mutations are the most frequent cause of a form of the disorder designated pontocerebellar hypoplasia type 2 (PCH2). When PCH2 results from TSEN54 gene mutations, it is sometimes categorized more specifically as PCH2A. Mutations in the TSEN54 gene also cause pontocerebellar hypoplasia type 4 (PCH4) and appear to be a rare cause of pontocerebellar hypoplasia type 1 (PCH1).

The most common mutation in the TSEN54 gene replaces the amino acid alanine with the amino acid serine at position 307 in the TSEN54 protein (written as Ala307Ser or A307S). About 90 percent of all people with PCH2 have this mutation in both copies of the TSEN54 gene in each cell. At least one person diagnosed with PCH1 also had the mutation in both copies of the gene. Most individuals with PCH4 have the common Ala307Ser mutation in one copy of the TSEN54 gene in each cell and a different mutation in the other copy of the gene.

The TSEN54 gene mutations that cause pontocerebellar hypoplasia impair the function of the tRNA splicing endonuclease complex, which likely disrupts the processing of RNA molecules and affects the production of many types of proteins. Before birth, these changes appear to have the most severe impact on fast-growing tissues, such as those in the brain. However, it is unknown exactly how reduced function of the tRNA splicing endonuclease complex leads to abnormal brain development in people with pontocerebellar hypoplasia.

Where is the TSEN54 gene located?

Cytogenetic Location: 17q25.1

Molecular Location on chromosome 17: base pairs 75,515,707 to 75,524,739

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The TSEN54 gene is located on the long (q) arm of chromosome 17 at position 25.1.

The TSEN54 gene is located on the long (q) arm of chromosome 17 at position 25.1.

More precisely, the TSEN54 gene is located from base pair 75,515,707 to base pair 75,524,739 on chromosome 17.

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

Where can I find additional information about TSEN54?

You and your healthcare professional may find the following resources about TSEN54 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 TSEN54 gene or gene products?

  • FLJ37147
  • SEN54
  • SEN54L
  • tRNA-intron endonuclease Sen54
  • tRNA splicing endonuclease 54 homolog
  • tRNA splicing endonuclease 54 homolog (S. cerevisiae)
  • TSEN54 tRNA splicing endonuclease subunit

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

What glossary definitions help with understanding TSEN54?

acids ; alanine ; amino acid ; cell ; disability ; DNA ; endonuclease ; enzyme ; gene ; hypoplasia ; intron ; messenger RNA ; mRNA ; mutation ; polyadenylation ; protein ; RNA ; serine ; splicing ; subunit ; transfer RNA ; tRNA

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


  • Bailey KA, Aldinger KA. Mutations in the tRNA splicing endonuclease complex cause pontocerebellar hypoplasia. Clin Genet. 2009 May;75(5):427-8. doi: 10.1111/j.1399-0004.2009.01186_3.x. (
  • Battini R, D'Arrigo S, Cassandrini D, Guzzetta A, Fiorillo C, Pantaleoni C, Romano A, Alfei E, Cioni G, Santorelli FM. Novel mutations in TSEN54 in pontocerebellar hypoplasia type 2. J Child Neurol. 2014 Apr;29(4):520-5. doi: 10.1177/0883073812470002. Epub 2013 Jan 9. (
  • Budde BS, Namavar Y, Barth PG, Poll-The BT, Nürnberg G, Becker C, van Ruissen F, Weterman MA, Fluiter K, te Beek ET, Aronica E, van der Knaap MS, Höhne W, Toliat MR, Crow YJ, Steinling M, Voit T, Roelenso F, Brussel W, Brockmann K, Kyllerman M, Boltshauser E, Hammersen G, Willemsen M, Basel-Vanagaite L, Krägeloh-Mann I, de Vries LS, Sztriha L, Muntoni F, Ferrie CD, Battini R, Hennekam RC, Grillo E, Beemer FA, Stoets LM, Wollnik B, Nürnberg P, Baas F. tRNA splicing endonuclease mutations cause pontocerebellar hypoplasia. Nat Genet. 2008 Sep;40(9):1113-8. doi: 10.1038/ng.204. (
  • Gene Review: TSEN54-Related Pontocerebellar Hypoplasia (
  • Namavar Y, Barth PG, Kasher PR, van Ruissen F, Brockmann K, Bernert G, Writzl K, Ventura K, Cheng EY, Ferriero DM, Basel-Vanagaite L, Eggens VR, Krägeloh-Mann I, De Meirleir L, King M, Graham JM Jr, von Moers A, Knoers N, Sztriha L, Korinthenberg R; PCH Consortium, Dobyns WB, Baas F, Poll-The BT. Clinical, neuroradiological and genetic findings in pontocerebellar hypoplasia. Brain. 2011 Jan;134(Pt 1):143-56. doi: 10.1093/brain/awq287. Epub 2010 Oct 15. (
  • NCBI Gene (
  • Rudaks LI, Moore L, Shand KL, Wilkinson C, Barnett CP. Novel TSEN54 mutation causing pontocerebellar hypoplasia type 4. Pediatr Neurol. 2011 Sep;45(3):185-8. doi: 10.1016/j.pediatrneurol.2011.05.009. (
  • Simonati A, Cassandrini D, Bazan D, Santorelli FM. TSEN54 mutation in a child with pontocerebellar hypoplasia type 1. Acta Neuropathol. 2011 May;121(5):671-3. doi: 10.1007/s00401-011-0823-1. Epub 2011 Apr 6. (


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: November 2014
Published: February 1, 2016