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POLR1D gene

RNA polymerase I and III subunit D

Normal Function

The POLR1D gene provides instructions for making one part (subunit) of two related enzymes called RNA polymerase I and RNA polymerase III. These enzymes are involved in the production (synthesis) of ribonucleic acid (RNA), a chemical cousin of DNA. Both enzymes help synthesize a form of RNA known as ribosomal RNA (rRNA). RNA polymerase III also plays a role in the synthesis of several other forms of RNA, including transfer RNA (tRNA). Ribosomal RNA and transfer RNA assemble protein building blocks (amino acids) into functioning proteins, which is essential for the normal functioning and survival of cells.

Based on its involvement in Treacher Collins syndrome, the POLR1D gene appears to play a critical role in the early development of structures that become bones and other tissues of the face.

Health Conditions Related to Genetic Changes

Treacher Collins syndrome

At least 20 mutations in the POLR1D gene have been identified in people with Treacher Collins syndrome, a condition that affects the development of bones and other tissues of the face. These mutations appear to alter the structure and function of the POLR1D protein, which reduces the amount of functional RNA polymerase I and RNA polymerase III in cells. Consequently, less rRNA is produced. Researchers speculate that a shortage of rRNA may trigger the self-destruction (apoptosis) of certain cells involved in the early development of facial bones and tissues. The abnormal cell death could underlie the specific problems with facial development found in Treacher Collins syndrome. However, it is unclear why the effects of a reduction in rRNA are limited to facial development.

More About This Health Condition


MedlinePlus Genetics provides information about Coloboma

More About This Health Condition

Other Names for This Gene

  • AC19
  • DNA-directed RNA polymerase I subunit D
  • DNA-directed RNA polymerases I and III subunit RPAC2
  • FLJ20616
  • MGC9850
  • polymerase (RNA) I polypeptide D
  • polymerase (RNA) I polypeptide D, 16kDa
  • polymerase (RNA) I subunit D
  • RNA polymerase I subunit D
  • RNA polymerases I and III subunit AC2
  • RPA16
  • RPA9
  • RPAC2
  • RPC16
  • RPO1-3

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Dauwerse JG, Dixon J, Seland S, Ruivenkamp CA, van Haeringen A, Hoefsloot LH, Peters DJ, Boers AC, Daumer-Haas C, Maiwald R, Zweier C, Kerr B, Cobo AM, Toral JF, Hoogeboom AJ, Lohmann DR, Hehr U, Dixon MJ, Breuning MH, Wieczorek D. Mutations in genes encoding subunits of RNA polymerases I and III cause Treacher Collins syndrome. Nat Genet. 2011 Jan;43(1):20-2. doi: 10.1038/ng.724. Epub 2010 Dec 5. Citation on PubMed
  • Fisher E. Exploring the genetic origins of Treacher Collins syndrome. Clin Genet. 2011 Apr;79(4):330-2. doi: 10.1111/j.1399-0004.2011.01632.x. Epub 2011 Feb 7. No abstract available. Citation on PubMed
  • Katsanis SH, Jabs EW. Treacher Collins Syndrome. 2004 Jul 20 [updated 2020 Aug 20]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from Citation on PubMed
  • Yao Y, Yamamoto K, Nishi Y, Nogi Y, Muramatsu M. Mouse RNA polymerase I 16-kDa subunit able to associate with 40-kDa subunit is a homolog of yeast AC19 subunit of RNA polymerases I and III. J Biol Chem. 1996 Dec 20;271(51):32881-5. doi: 10.1074/jbc.271.51.32881. Citation on PubMed

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