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

POLR gene family

Reviewed June 2013

What are the POLR genes?

Genes in the POLR family provide instructions for making parts (subunits) of three enzymes called RNA polymerases I, II, and III. These enzymes attach (bind) to DNA and produce (synthesize) RNA (a chemical cousin of DNA) in accordance with the instructions carried by the DNA. This process is known as transcription.

RNA polymerase II transcribes genes that provide instructions for making proteins, yielding messenger RNA (mRNA), which serves as the genetic blueprint for protein production. RNA polymerases I and III help synthesize several forms of RNA, including ribosomal RNA (rRNA) and transfer RNA (tRNA). Molecules of rRNA and tRNA assemble protein building blocks (amino acids) into working proteins; this process is essential for the normal functioning and survival of cells.

Mutations in genes in the POLR family can result in developmental problems affecting a variety of organs and systems in the body.

Which genes are included in the POLR 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 POLR gene family: POLR1C, POLR1D, POLR3A, and POLR3B.

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

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

  • Pol III-related leukodystrophy
  • Treacher Collins syndrome

What glossary definitions help with understanding the POLR gene family?

acids ; DNA ; messenger RNA ; mRNA ; protein ; ribosomal RNA ; RNA ; RNA polymerase ; transcription ; transfer RNA ; tRNA

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 POLR gene family.

  • The Cell: A Molecular Approach (second edition, 2000): Eukaryotic RNA Polymerases and General Transcription Factors (
  • Lane WJ, Darst SA. Molecular evolution of multisubunit RNA polymerases: sequence analysis. J Mol Biol. 2010 Jan 29;395(4):671-85. doi: 10.1016/j.jmb.2009.10.062. Epub 2009 Nov 3. (
  • Wild T, Cramer P. Biogenesis of multisubunit RNA polymerases. Trends Biochem Sci. 2012 Mar;37(3):99-105. doi: 10.1016/j.tibs.2011.12.001. Epub 2012 Jan 17. Review. (
  • Cramer P, Armache KJ, Baumli S, Benkert S, Brueckner F, Buchen C, Damsma GE, Dengl S, Geiger SR, Jasiak AJ, Jawhari A, Jennebach S, Kamenski T, Kettenberger H, Kuhn CD, Lehmann E, Leike K, Sydow JF, Vannini A. Structure of eukaryotic RNA polymerases. Annu Rev Biophys. 2008;37:337-52. doi: 10.1146/annurev.biophys.37.032807.130008. Review. (
  • Archambault J, Friesen JD. Genetics of eukaryotic RNA polymerases I, II, and III. Microbiol Rev. 1993 Sep;57(3):703-24. 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: June 2013
Published: February 1, 2016