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


Reviewed June 2015

What is the official name of the PEX1 gene?

The official name of this gene is “peroxisomal biogenesis factor 1.”

PEX1 is the gene's official symbol. The PEX1 gene is also known by other names, listed below.

What is the normal function of the PEX1 gene?

The PEX1 gene provides instructions for making a protein called peroxisomal biogenesis factor 1 (Pex1p), which is part of a group of proteins called peroxins. Peroxins are essential for the formation and normal functioning of cell structures called peroxisomes. Peroxisomes are sac-like compartments that contain enzymes needed to break down many different substances, including fatty acids and certain toxic compounds. They are also important for the production of fats (lipids) used in digestion and in the nervous system. Peroxins assist in the formation (biogenesis) of peroxisomes by producing the membrane that separates the peroxisome from the rest of the cell and by importing enzymes into the peroxisome. Pex1p enables other peroxins to bring enzymes into the peroxisome.

How are changes in the PEX1 gene related to health conditions?

Zellweger spectrum disorder - caused by mutations in the PEX1 gene

At least 114 mutations in the PEX1 gene have been identified in people with Zellweger spectrum disorder, which is a group of conditions that have overlapping signs and symptoms and affect many parts of the body. The conditions' features, which vary in severity, can include weak muscle tone (hypotonia), developmental delay, and vision and hearing problems. Mutations in the PEX1 gene are the most common cause of Zellweger spectrum disorder and are found in nearly 70 percent of affected individuals.

There are two common PEX1 gene mutations found in people with Zellweger spectrum disorder. One mutation replaces the protein building block (amino acid) glycine with the amino acid aspartic acid at position 843 in Pex1p (written as Gly843Asp or G843D). This mutation leads to reduced levels of the protein. Individuals who have the G843D mutation tend to have signs and symptoms that are at the less-severe end of the condition spectrum. The other common mutation, which is known as the 1700fs mutation, leads to the production of an abnormally short, nonfunctional Pex1p. People who have the 1700fs mutation often have signs and symptoms that are at the severe end of the condition spectrum.

Mutations in the PEX1 gene that cause Zellweger spectrum disorder reduce or eliminate the activity of the Pex1p protein. Without enough functional Pex1p, enzymes are not properly imported into peroxisomes. As a result, cells contain empty peroxisomes that cannot carry out their usual functions. The severe end of the condition spectrum is caused by the absence of functional peroxisomes within cells. The less severe end of the condition spectrum results from mutations that allow some peroxisomes to form.

Where is the PEX1 gene located?

Cytogenetic Location: 7q21.2

Molecular Location on chromosome 7: base pairs 92,487,023 to 92,528,531

The PEX1 gene is located on the long (q) arm of chromosome 7 at position 21.2.

The PEX1 gene is located on the long (q) arm of chromosome 7 at position 21.2.

More precisely, the PEX1 gene is located from base pair 92,487,023 to base pair 92,528,531 on chromosome 7.

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

Where can I find additional information about PEX1?

You and your healthcare professional may find the following resources about PEX1 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 PEX1 gene or gene products?

  • peroxin1
  • peroxisome biogenesis disorder protein 1
  • Pex1p
  • ZWS1

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

What glossary definitions help with understanding PEX1?

acids ; amino acid ; aspartic acid ; cell ; developmental delay ; digestion ; fatty acids ; gene ; glycine ; hypotonia ; muscle tone ; mutation ; nervous system ; peroxisomes ; protein ; spectrum ; toxic

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


  • Crane DI, Maxwell MA, Paton BC. PEX1 mutations in the Zellweger spectrum of the peroxisome biogenesis disorders. Hum Mutat. 2005 Sep;26(3):167-75. Review. (
  • Ebberink MS, Mooijer PA, Gootjes J, Koster J, Wanders RJ, Waterham HR. Genetic classification and mutational spectrum of more than 600 patients with a Zellweger syndrome spectrum disorder. Hum Mutat. 2011 Jan;32(1):59-69. doi: 10.1002/humu.21388. (
  • Fujiki Y, Miyata N, Matsumoto N, Tamura S. Dynamic and functional assembly of the AAA peroxins, Pex1p and Pex6p, and their membrane receptor Pex26p involved in shuttling of the PTS1 receptor Pex5p in peroxisome biogenesis. Biochem Soc Trans. 2008 Feb;36(Pt 1):109-13. doi: 10.1042/BST0360109. Review. (
  • Gene Review: Peroxisome Biogenesis Disorders, Zellweger Syndrome Spectrum (
  • NCBI Gene (
  • Rosenkranz K, Birschmann I, Grunau S, Girzalsky W, Kunau WH, Erdmann R. Functional association of the AAA complex and the peroxisomal importomer. FEBS J. 2006 Aug;273(16):3804-15. (
  • Rosewich H, Ohlenbusch A, Gärtner J. Genetic and clinical aspects of Zellweger spectrum patients with PEX1 mutations. J Med Genet. 2005 Sep;42(9):e58. (
  • Thoms S, Erdmann R. Peroxisomal matrix protein receptor ubiquitination and recycling. Biochim Biophys Acta. 2006 Dec;1763(12):1620-8. Epub 2006 Sep 3. Review. (
  • Wanders RJ, Waterham HR. Peroxisomal disorders I: biochemistry and genetics of peroxisome biogenesis disorders. Clin Genet. 2005 Feb;67(2):107-33. 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 2015
Published: November 23, 2015