Prolidase Deficiency - Causes and Genetics

Causes and Genetics

The mutations on the PEPD (peptidase-D) gene result the development of prolidase deficiency. The location of this gene is on chromosome 19 and it contains the instructions on how to make the enzyme prolidase. Prolidase plays a part in destroying and recycling proteins, like collagen. This gene presents information for the creation of prolidase, an enzyme, which is known as peptidase-D. Prolidase assists in the division of specific dipeptides. Dipeptides are molecules that are made up of two components that are, protein building blocks (amino acids). Exclusively, prolidase separates dipeptides that contain proline of hydroxyproline, which are both amino acids. By releasing those amino acids, prolidase can help to prepare them for use in generating proteins which are essential to the body.

Prolidase is associated with the last part of in the breaking down of some proteins that are acquired via diet and the proteins which the body does not find necessary anymore. Prolidase is essential for collagen biosynthesis and its inadequacy causes deterioration in the connective tissue of the skin, capillaries, and lymphatic tissue. Mutations of the prolidase gene results in the activity of prolidase being decreased or completely lost, which causes PD.

It has been proposed that the build up of dipeptides which have not yet been broken down, can induce the death of cells. After cells die, the volume of the cell is expelled within the neighboring tissue and that may result in inflammation and give rise to problems of the skin as seen in PD. Also said that if the breaking down of collagen is defective while the extracellular matrix (ECM) is undergoing alteration, that it could cause problems with the skin as well. Collagen is a protein that is widely scattered throughout the body and it serves to support the structure of internal organs and connective tissues. The mental impairment that can develop in those with PD might arise from complications involving the management of neuropeptides. Neuropeptides are the proteins that have an abundance of proline and help with communication in the brain.

At least 19 mutations in the PEPD gene have been identified in individuals with prolidase deficiency. The mutations on the PEPD gene seen in individuals affected by PD, result in the prolidase enzyme action being lost.

This condition is inherited in an autosomal recessive fashion, meaning that the two copies of the gene in every cell contain mutations. Each of the parents of the person who suffers from an autosomal recessive disorder possesses one copy of the mutant gene, but they usually do not exhibit the signs and symptoms of the disorder.