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The official name of this gene is “protein tyrosine phosphatase, non-receptor type 22 (lymphoid).”
PTPN22 is the gene's official symbol. The PTPN22 gene is also known by other names, listed below.
The PTPN22 gene provides instructions for making a protein that belongs to the PTP (protein tyrosine phosphatases) family. PTP proteins play a role in regulating a process called signal transduction. In signal transduction, the protein relays signals from outside the cell to the cell nucleus. These signals instruct the cell to grow and divide or to mature and take on specialized functions.
The PTPN22 protein is involved in signaling that helps control the activity of immune system cells called T cells. T cells identify foreign substances and defend the body against infection.
The PTPN22 gene belongs to a family of genes called PTP (protein tyrosine phosphatases).
A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.
Studies have associated a variation in the PTPN22 gene with an increased risk of several autoimmune disorders. Autoimmune disorders occur when the immune system malfunctions and attacks the body's tissues and organs. These disorders include type 1 diabetes, rheumatoid arthritis, autoimmune thyroid disease, and systemic lupus erythematosus.
The PTPN22 gene variation associated with autoimmune disorders changes the protein building block (amino acid) arginine to the amino acid tryptophan at position 620 in the PTPN22 protein sequence, written as Arg620Trp or R620W. This variation likely affects the activity of the PTPN22 protein, making it more difficult for the body to control inflammation and prevent the immune system from attacking its own tissues.
Studies have associated the R620W variation in the PTPN22 gene with an increased risk of vitiligo, an autoimmune condition that results in patchy changes in skin coloring (pigmentation).
As with other autoimmune disorders, this variation likely affects the activity of the PTPN22 protein, making it more difficult for the body to control the immune system and prevent it from attacking its own tissues. While the pigment loss associated with vitiligo results from the immune system attacking pigment-producing cells (melanocytes) in the skin, it is unclear what specific circumstances trigger the immune system to do so. The condition probably results from a combination of genetic and environmental factors, most of which have not been identified.
Cytogenetic Location: 1p13.2
Molecular Location on chromosome 1: base pairs 113,813,810 to 113,871,752
The PTPN22 gene is located on the short (p) arm of chromosome 1 at position 13.2.
More precisely, the PTPN22 gene is located from base pair 113,813,810 to base pair 113,871,752 on chromosome 1.
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 PTPN22 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.
amino acid ; arginine ; arthritis ; autoimmune ; cell ; cell nucleus ; diabetes ; domain ; gene ; hematopoietic ; idiopathic ; immune system ; infection ; inflammation ; juvenile ; lupus ; lymphoid ; melanocytes ; nucleus ; phosphatase ; pigment ; pigmentation ; protein ; protein sequence ; receptor ; signal transduction ; systemic lupus ; systemic lupus erythematosus ; thyroid ; transduction ; tryptophan ; tyrosine
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.