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


Reviewed December 2009

What is the official name of the TSEN2 gene?

The official name of this gene is “tRNA splicing endonuclease 2 homolog (S. cerevisiae).”

TSEN2 is the gene's official symbol. The TSEN2 gene is also known by other names, listed below.

What is the normal function of the TSEN2 gene?

The TSEN2 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 known as amino acids into full-length proteins. However, before they can assemble proteins, tRNAs must be processed into mature molecules. In particular, some tRNA molecules contain regions called introns that need to be removed for the tRNAs 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 TSEN2 gene related to health conditions?

pontocerebellar hypoplasia - caused by mutations in the TSEN2 gene

At least one mutation in the TSEN2 gene has been found to cause pontocerebellar hypoplasia type 2 (PCH2). This mutation replaces the amino acid tyrosine with the amino acid cysteine at position 309 in the TSEN2 protein (written as Tyr309Cys or Y309C). It is unclear how mutations in this gene alter the function of the tRNA splicing endonuclease complex and disrupt normal brain development. Researchers believe that TSEN2 gene mutations are probably responsible for only a small percentage of all cases of PCH2.

Where is the TSEN2 gene located?

Cytogenetic Location: 3p25.2

Molecular Location on chromosome 3: base pairs 12,484,431 to 12,539,629

The TSEN2 gene is located on the short (p) arm of chromosome 3 at position 25.2.

The TSEN2 gene is located on the short (p) arm of chromosome 3 at position 25.2.

More precisely, the TSEN2 gene is located from base pair 12,484,431 to base pair 12,539,629 on chromosome 3.

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

Where can I find additional information about TSEN2?

You and your healthcare professional may find the following resources about TSEN2 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 TSEN2 gene or gene products?

  • HsSen2
  • MGC2776
  • MGC4440
  • SEN2
  • SEN2L
  • tRNA-intron nuclease 2

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

What glossary definitions help with understanding TSEN2?

acids ; amino acid ; cysteine ; DNA ; endonuclease ; enzyme ; gene ; hypoplasia ; intron ; messenger RNA ; mRNA ; mutation ; nuclease ; polyadenylation ; protein ; RNA ; splicing ; subunit ; transfer RNA ; tRNA ; tyrosine

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. (
  • Bierhals T, Korenke GC, Uyanik G, Kutsche K. Pontocerebellar hypoplasia type 2 and TSEN2: review of the literature and two novel mutations. Eur J Med Genet. 2013 Jun;56(6):325-30. doi: 10.1016/j.ejmg.2013.03.009. Epub 2013 Apr 3. Review. (
  • 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. (
  • 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 (
  • Paushkin SV, Patel M, Furia BS, Peltz SW, Trotta CR. Identification of a human endonuclease complex reveals a link between tRNA splicing and pre-mRNA 3' end formation. Cell. 2004 Apr 30;117(3):311-21. (


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: October 27, 2014