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The official name of this gene is “peripherin.”
PRPH is the gene's official symbol. The PRPH gene is also known by other names, listed below.
The PRPH gene provides instructions for making a protein called peripherin. Several molecules of peripherin attach (bind) together to form intermediate filaments, which provide support and strength to cells. Intermediate filaments also assist in determining the placement of the nucleus and other specialized structures within the cell. In addition, these filaments appear to relay signals from the cell surface to the nucleus. These signals play a role in regulating cell development and growth.
The intermediate filaments composed of peripherin are found in nerve cells of the peripheral nervous system, which connects the brain and spinal cord to muscles and to cells that detect sensations such as touch, smell, and sound (sensory cells). Additional peripherin is made when nerves are injured, which suggests that it plays a role in the repair of nerve cells. In particular, intermediate filaments made up of peripherin may be involved in the regrowth of axons, the specialized extensions of nerve cells that are essential for the transmission of nerve impulses.
Researchers have identified at least two mutations in the PRPH gene that increase the risk of developing amyotrophic lateral sclerosis (ALS), a condition characterized by progressive movement problems and muscle wasting. One mutation, written as 228delC, deletes a single DNA building block (nucleotide) from the PRPH gene. This mutation likely leads to an abnormally small peripherin protein, which appears to have an impaired ability to bind with other peripherin proteins and assemble into intermediate filaments.
Another PRPH gene mutation associated with ALS changes one of the protein building blocks (amino acids) used to make peripherin. Specifically, the amino acid aspartic acid is replaced with the amino acid tyrosine at protein position 141 (written as Asp141Tyr or D141Y). This change probably affects the 3-dimensional shape of peripherin and leads to a buildup of clumps (aggregates) of this protein within nerve cells.
It is unclear how PRPH gene mutations increase the risk of developing ALS. Aggregates of peripherin and impaired intermediate filament formation likely disrupt normal nerve functions. The progressive loss of these nerve cells underlies the signs and symptoms of ALS.
Cytogenetic Location: 12q12-q13
Molecular Location on chromosome 12: base pairs 49,295,012 to 49,298,697
The PRPH gene is located on the long (q) arm of chromosome 12 between positions 12 and 13.
More precisely, the PRPH gene is located from base pair 49,295,012 to base pair 49,298,697 on chromosome 12.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
You and your healthcare professional may find the following resources about PRPH helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
acids ; amino acid ; aspartic acid ; axons ; cell ; DNA ; gene ; intermediate filaments ; mutation ; nervous system ; neurofilament ; nucleotide ; nucleus ; peripheral ; peripheral nervous system ; protein ; sclerosis ; sensory cells ; tyrosine ; wasting
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).
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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.