Skip Navigation
Genetics Home Reference: your guide to understanding genetic conditions
http://ghr.nlm.nih.gov/     A service of the U.S. National Library of Medicine®

PIGV

Reviewed August 2013

What is the official name of the PIGV gene?

The official name of this gene is “phosphatidylinositol glycan anchor biosynthesis, class V.”

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

What is the normal function of the PIGV gene?

The PIGV gene provides instructions for making an enzyme called GPI mannosyltransferase 2. This enzyme takes part in a series of steps that produce a molecule called a glycosylphosphosphatidylinositol (GPI) anchor. Specifically, GPI mannosyltransferase 2 adds the second of three molecules of a complex sugar called mannose to the GPI anchor. This step takes place in the endoplasmic reticulum, which is a structure involved in protein processing and transport within cells. The complete GPI anchor attaches (binds) to various proteins in the endoplasmic reticulum. After the anchor and protein are bound, the anchor attaches itself to the outer surface of the cell membrane, ensuring that the protein will be available when it is needed.

Does the PIGV gene share characteristics with other genes?

The PIGV gene belongs to a family of genes called dolichyl D-mannosyl phosphate dependent mannosyltransferases (dolichyl D-mannosyl phosphate dependent mannosyltransferases). It also belongs to a family of genes called PIG (phosphatidylinositol glycan anchor biosynthesis).

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.

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

Mabry syndrome - caused by mutations in the PIGV gene

At least 14 mutations in the PIGV gene have been found to cause Mabry syndrome, a condition characterized by intellectual disability, distinctive facial features, increased levels of an enzyme called alkaline phosphatase in the blood (hyperphosphatasia), and other signs and symptoms. These mutations change single protein building blocks (amino acids) in the GPI mannosyltransferase 2 enzyme. The altered protein is less able to add mannose to the forming GPI anchor. The incomplete GPI anchor cannot attach to proteins; without the anchor, the proteins cannot bind to the cell membrane and are released from the cell.

An enzyme called alkaline phosphatase is normally attached to a GPI anchor. However, when the anchor is impaired, alkaline phosphatase cannot be anchored to the cell membrane. Instead, alkaline phosphatase is released from the cell. This abnormal release of alkaline phosphatase is responsible for the hyperphosphatasia in Mabry syndrome. It is unclear how PIGV gene mutations lead to the other features of Mabry syndrome, but these signs and symptoms are likely due to a lack of proper GPI anchoring of proteins to cell membranes.

Where is the PIGV gene located?

Cytogenetic Location: 1p36.11

Molecular Location on chromosome 1: base pairs 26,787,962 to 26,798,402

The PIGV gene is located on the short (p) arm of chromosome 1 at position 36.11.

The PIGV gene is located on the short (p) arm of chromosome 1 at position 36.11.

More precisely, the PIGV gene is located from base pair 26,787,962 to base pair 26,798,402 on chromosome 1.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about PIGV?

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

  • dol-P-Man dependent GPI mannosyltransferase
  • FLJ20477
  • GPI mannosyltransferase 2
  • GPI mannosyltransferase II
  • GPI-MT-II
  • HPMRS1
  • PIG-V
  • PIGV_HUMAN

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding PIGV?

acids ; cell ; cell membrane ; class ; disability ; endoplasmic reticulum ; enzyme ; gene ; glycan ; mannose ; molecule ; phosphatase ; protein ; syndrome

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

References

  • Horn D, Krawitz P, Mannhardt A, Korenke GC, Meinecke P. Hyperphosphatasia-mental retardation syndrome due to PIGV mutations: expanded clinical spectrum. Am J Med Genet A. 2011 Aug;155A(8):1917-22. doi: 10.1002/ajmg.a.34102. Epub 2011 Jul 7. (http://www.ncbi.nlm.nih.gov/pubmed/21739589?dopt=Abstract)
  • Krawitz PM, Schweiger MR, Rödelsperger C, Marcelis C, Kölsch U, Meisel C, Stephani F, Kinoshita T, Murakami Y, Bauer S, Isau M, Fischer A, Dahl A, Kerick M, Hecht J, Köhler S, Jäger M, Grünhagen J, de Condor BJ, Doelken S, Brunner HG, Meinecke P, Passarge E, Thompson MD, Cole DE, Horn D, Roscioli T, Mundlos S, Robinson PN. Identity-by-descent filtering of exome sequence data identifies PIGV mutations in hyperphosphatasia mental retardation syndrome. Nat Genet. 2010 Oct;42(10):827-9. doi: 10.1038/ng.653. Epub 2010 Aug 29. (http://www.ncbi.nlm.nih.gov/pubmed/20802478?dopt=Abstract)
  • Murakami Y, Kanzawa N, Saito K, Krawitz PM, Mundlos S, Robinson PN, Karadimitris A, Maeda Y, Kinoshita T. Mechanism for release of alkaline phosphatase caused by glycosylphosphatidylinositol deficiency in patients with hyperphosphatasia mental retardation syndrome. J Biol Chem. 2012 Feb 24;287(9):6318-25. doi: 10.1074/jbc.M111.331090. Epub 2012 Jan 6. (http://www.ncbi.nlm.nih.gov/pubmed/22228761?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/55650)
  • OMIM: PHOSPHATIDYLINOSITOL GLYCAN, CLASS V (http://omim.org/entry/610274)
  • Thompson MD, Roscioli T, Marcelis C, Nezarati MM, Stolte-Dijkstra I, Sharom FJ, Lu P, Phillips JA, Sweeney E, Robinson PN, Krawitz P, Yntema HG, Andrade DM, Brunner HG, Cole DE. Phenotypic variability in hyperphosphatasia with seizures and neurologic deficit (Mabry syndrome). Am J Med Genet A. 2012 Mar;158A(3):553-8. doi: 10.1002/ajmg.a.35202. Epub 2012 Feb 7. (http://www.ncbi.nlm.nih.gov/pubmed/22315194?dopt=Abstract)

 

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.

 
Reviewed: August 2013
Published: July 27, 2015