Skip navigation

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

URL of this page:

PRDX1 gene

peroxiredoxin 1

Normal Function

The PRDX1 gene provides instructions for making the peroxiredoxin-1 (PRDX1) protein. This protein is part of a family of peroxiredoxin proteins that are primarily involved in chemical reactions that protect cells from damage caused by unstable oxygen-containing molecules known as reactive oxygen species (ROS).

The PRDX1 protein breaks down hydrogen peroxide. Hydrogen peroxide is produced through chemical reactions within cells. At low levels, it is involved in several chemical signaling pathways that control cell functions like growth, maturation, and survival. By regulating the amount of hydrogen peroxide in cells, the PRDX1 protein appears to help control these chemical signaling pathways, playing a role in important cellular functions.

At high levels hydrogen peroxide, an ROS, is toxic to cells. If hydrogen peroxide is not broken down, it can damage DNA, proteins, and cell membranes. The PRDX1 protein helps protect cells from this damage.

The PRDX1 gene is close to another gene on chromosome 1 called MMACHC. These two genes have unrelated roles in cells. The protein produced from the MMACHC gene is involved in processing vitamin B12 (also known as cobalamin).

Health Conditions Related to Genetic Changes

Methylmalonic acidemia with homocystinuria

Variants (also known as mutations) in the PRDX1 gene are involved in methylmalonic acidemia with homocystinuria, epi-cblC type (shortened to epi-cblC), which is one form of a disorder that causes developmental delay, eye defects, neurological problems, and blood abnormalities. 

Variants in the PRDX1 gene cause epi-cblC by leading to a genetic change called promoter hypermethylation. (This genetic change is also called an epimutation). The promoter is a region of DNA near a gene that controls gene activity (expression). Hypermethylation occurs when too many small molecules called methyl groups are attached to the promoter region. PRDX1 gene variants involved in epi-cblC alter the DNA in such a way that the promoter of the nearby MMACHC gene becomes hypermethylated. The extra methyl groups reduce the expression of the MMACHC gene, which means that less MMACHC protein is produced.

People with epi-cblC with a PRDX1 gene variant on one copy of the chromosome usually have an MMACHC gene variant on the other copy. (Very rarely, an affected individual has  a PRDX1 gene variant on both copies of the chromosome and no MMACHC gene variant.) As a result, cells make little to no functional MMACHC protein. A reduction in this protein's function prevents normal processing of vitamin B12. This vitamin is usually converted to two important molecules. A shortage of both molecules leads to the signs and symptoms of methylmalonic acidemia with homocystinuria. 

Research suggests that PRDX1 gene variants may also lead to hypermethylation of other gene promoters. It is unclear if reduced expression of other genes plays a role in the development of epi-cblC. In addition, the effect of PRDX1 gene variants on the production or function of the peroxiredoxin-1 protein is unclear. More studies are needed to understand if hypermethylation of additional promoters or changes to peroxiredoxin-1 contribute to methylmalonic acidemia with homocystinuria or cause additional signs or symptoms in affected individuals.

More About This Health Condition

Other Names for This Gene

  • MSP23
  • natural killer-enhancing factor A
  • NKEF-A
  • PAG
  • PAGA
  • PAGB
  • proliferation-associated gene A
  • PRX1
  • PRXI
  • TDPX2

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


  • Cavicchi C, Oussalah A, Falliano S, Ferri L, Gozzini A, Gasperini S, Motta S, Rigoldi M, Parenti G, Tummolo A, Meli C, Menni F, Furlan F, Daniotti M, Malvagia S, la Marca G, Chery C, Morange PE, Tregouet D, Donati MA, Guerrini R, Gueant JL, Morrone A. PRDX1 gene-related epi-cblC disease is a common type of inborn error of cobalamin metabolism with mono- or bi-allelic MMACHC epimutations. Clin Epigenetics. 2021 Jul 2;13(1):137. doi: 10.1186/s13148-021-01117-2. Citation on PubMed
  • Gueant JL, Chery C, Oussalah A, Nadaf J, Coelho D, Josse T, Flayac J, Robert A, Koscinski I, Gastin I, Filhine-Tresarrieu P, Pupavac M, Brebner A, Watkins D, Pastinen T, Montpetit A, Hariri F, Tregouet D, Raby BA, Chung WK, Morange PE, Froese DS, Baumgartner MR, Benoist JF, Ficicioglu C, Marchand V, Motorin Y, Bonnemains C, Feillet F, Majewski J, Rosenblatt DS. APRDX1 mutant allele causes a MMACHC secondary epimutation in cblC patients. Nat Commun. 2018 Jan 4;9(1):67. doi: 10.1038/s41467-017-02306-5. Erratum In: Nat Commun. 2018 Feb 2;9(1):554. Citation on PubMed
  • Neumann CA, Cao J, Manevich Y. Peroxiredoxin 1 and its role in cell signaling. Cell Cycle. 2009 Dec 15;8(24):4072-8. doi: 10.4161/cc.8.24.10242. Epub 2009 Dec 5. Citation on PubMed
  • Oussalah A, Siblini Y, Hergalant S, Chery C, Rouyer P, Cavicchi C, Guerrini R, Morange PE, Tregouet D, Pupavac M, Watkins D, Pastinen T, Chung WK, Ficicioglu C, Feillet F, Froese DS, Baumgartner MR, Benoist JF, Majewski J, Morrone A, Rosenblatt DS, Gueant JL. Epimutations in both the TESK2 and MMACHC promoters in the Epi-cblC inherited disorder of intracellular metabolism of vitamin B12. Clin Epigenetics. 2022 Apr 19;14(1):52. doi: 10.1186/s13148-022-01271-1. Citation on PubMed

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.