Skip Navigation
Genetics Home Reference: your guide to understanding genetic conditions About   Site Map   Contact Us
Home A service of the U.S. National Library of Medicine®
Printer-friendly version


Reviewed February 2012

What is the official name of the PEPD gene?

The official name of this gene is “peptidase D.”

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

Read more about gene names and symbols on the About page.

What is the normal function of the PEPD gene?

The PEPD gene provides instructions for making the enzyme prolidase, also called peptidase D. Prolidase helps divide certain dipeptides, which are molecules composed of two protein building blocks (amino acids). Specifically, prolidase divides dipeptides containing the amino acids proline or hydroxyproline. By freeing these amino acids, prolidase helps make them available for use in producing proteins that the body needs.

Prolidase is also involved in the final step of the breakdown of some proteins obtained though the diet and proteins that are no longer needed in the body. Prolidase is particularly important in the breakdown of collagens, a family of proteins that are rich in proline and hydroxyproline. Collagens are an important part of the extracellular matrix, which is the lattice of proteins and other molecules outside the cell. The extracellular matrix strengthens and supports connective tissues, such as skin, bone, cartilage, tendons, and ligaments. Collagen breakdown occurs during the maintenance (remodeling) of the extracellular matrix.

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

prolidase deficiency - caused by mutations in the PEPD gene

At least 19 mutations in the PEPD gene have been identified in people with prolidase deficiency, a disorder with a wide variety of signs and symptoms including skin problems and intellectual disability. The PEPD gene mutations identified in people with prolidase deficiency result in the loss of prolidase enzyme activity.

It is not well understood how the absence of prolidase activity results in the various signs and symptoms of prolidase deficiency. Researchers have suggested that accumulation of dipeptides that have not been broken down may lead to cell death. When cells die, their contents are released into the surrounding tissue, which could cause inflammation and lead to the skin problems seen in prolidase deficiency. Impaired collagen breakdown during remodeling of the extracellular matrix may also contribute to the skin problems. The intellectual disability that occurs in prolidase deficiency might result from problems in processing neuropeptides, which are brain signaling proteins that are rich in proline. It is unclear how absence of prolidase activity results in the other features of prolidase deficiency.

Where is the PEPD gene located?

Cytogenetic Location: 19q13.11

Molecular Location on chromosome 19: base pairs 33,386,949 to 33,521,893

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBIThis link leads to a site outside Genetics Home Reference.)

The PEPD gene is located on the long (q) arm of chromosome 19 at position 13.11.

The PEPD gene is located on the long (q) arm of chromosome 19 at position 13.11.

More precisely, the PEPD gene is located from base pair 33,386,949 to base pair 33,521,893 on chromosome 19.

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

Where can I find additional information about PEPD?

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

  • aminoacyl-L-proline hydrolase
  • imidodipeptidase
  • MGC10905
  • proline dipeptidase
  • xaa-Pro dipeptidase
  • X-Pro dipeptidase

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding PEPD?

acids ; breakdown ; cartilage ; cell ; collagen ; deficiency ; disability ; enzyme ; extracellular ; extracellular matrix ; gene ; hydrolase ; inflammation ; L-proline ; Pro ; proline ; protein ; tissue

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

See also Understanding Medical Terminology.

References (10 links)


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: February 2012
Published: February 8, 2016