SIGN IN YOUR ACCOUNT TO HAVE ACCESS TO DIFFERENT FEATURES

FORGOT YOUR PASSWORD?

FORGOT YOUR DETAILS?

AAH, WAIT, I REMEMBER NOW!
24/7 HELPLINE (903) 212-7500
  • PATIENT PORTAL LOGIN

PhyNet Health PhyNet Health

  • Home
  • Find a Clinic
    • Hughes Springs, TX
    • Longview, TX
    • Jefferson, TX
    • Kilgore, TX
    • Lindale, TX
    • Linden, TX
    • Gladewater, TX
    • Lone Star, TX
    • Tatum, TX
    • Marshall, TX
  • Health Services
    • Primary Care Services
    • Physical Therapy / Rehab
    • Allergy Testing & Treatment
    • Chronic Care Management
    • Remote Monitoring Program
    • Virtual Visit
  • Resources
    • MedlinePlus Wiki
      • Health Topics
    • Home Health Coordination
    • Transitions of Care
    • Insurance Help
  • About Phynet
    • About Phynet
    • PhyNet News
    • Better Together Stories
    • Careers
  • Billing

Health Topics

Skip navigation

An official website of the United States government

Here’s how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( Lock Locked padlock icon ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

National Institutes of Health National Library of Medicine
MedlinePlus Trusted Health Information for You
  • Health Topics
  • Drugs & Supplements
  • Genetics
  • Medical Tests
  • Medical Encyclopedia
  • About MedlinePlus
  • About MedlinePlus
  • What's New
  • Site Map
  • Customer Support
  • Health Topics
  • Drugs & Supplements
  • Genetics
  • Medical Tests
  • Medical Encyclopedia
You Are Here:
Home →
Genetics →
Genes →
PHKA1 gene
URL of this page: https://medlineplus.gov/genetics/gene/phka1/

PHKA1 gene

phosphorylase kinase regulatory subunit alpha 1

Normal Function

The PHKA1 gene provides instructions for making one piece, the alpha subunit, of the phosphorylase b kinase enzyme. This enzyme is made up of 16 subunits, four each of the alpha, beta, gamma, and delta subunits. (Each subunit is produced from a different gene.) The alpha subunit helps regulate the activity of phosphorylase b kinase. This enzyme is found in various tissues, although it is most abundant in the liver and muscles. One version of the enzyme is found in liver cells and another in muscle cells. The alpha-1 subunit produced from the PHKA1 gene is part of the enzyme found in muscle cells.

Phosphorylase b kinase plays an important role in providing energy for cells. The main source of cellular energy is a simple sugar called glucose. Glucose is stored in muscle and liver cells in a form called glycogen. Glycogen can be broken down rapidly when glucose is needed, for instance during exercise. Phosphorylase b kinase turns on (activates) another enzyme called glycogen phosphorylase b by converting it to the more active form, glycogen phosphorylase a. When active, this enzyme breaks down glycogen.

Health Conditions Related to Genetic Changes

Glycogen storage disease type IX

At least seven mutations in the PHKA1 gene are known to cause a form of glycogen storage disease type IX (GSD IX) called GSD IXd or X-linked muscle glycogenosis. This form of the disorder is rare and not well understood. It affects muscles and can cause muscle weakness, pain, and cramping, particularly during exercise, although some affected individuals have no signs or symptoms of the condition. Mutations in the PHKA1 gene reduce the activity of phosphorylase b kinase in muscle cells, although the mechanism is unknown. Reduction of this enzyme's function impairs glycogen breakdown. As a result, glycogen builds up in cells, and glucose is not available for energy. Reduced energy production in muscle cells leads to the features of GSD IXd.

More About This Health Condition

Other Names for This Gene

  • KPB1_HUMAN
  • PHKA
  • phosphorylase b kinase regulatory subunit alpha, skeletal muscle isoform
  • phosphorylase kinase alpha M subunit
  • phosphorylase kinase, alpha 1 (muscle)
  • phosphorylase kinase, alpha 1 (muscle), muscle glycogenosis

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

  • Tests of PHKA1 From the National Institutes of Health

Scientific Articles on PubMed

  • PubMed From the National Institutes of Health

Catalog of Genes and Diseases from OMIM

  • PHOSPHORYLASE KINASE, MUSCLE, ALPHA-1 SUBUNIT; PHKA1

Gene and Variant Databases

  • NCBI Gene From the National Institutes of Health
  • ClinVar From the National Institutes of Health

References

  • Brushia RJ, Walsh DA. Phosphorylase kinase: the complexity of its regulation is reflected in the complexity of its structure. Front Biosci. 1999 Sep 15;4:D618-41. doi: 10.2741/brushia. Citation on PubMed
  • Orngreen MC, Schelhaas HJ, Jeppesen TD, Akman HO, Wevers RA, Andersen ST, ter Laak HJ, van Diggelen OP, DiMauro S, Vissing J. Is muscle glycogenolysis impaired in X-linked phosphorylase b kinase deficiency? Neurology. 2008 May 13;70(20):1876-82. doi: 10.1212/01.wnl.0000289190.66955.67. Epub 2008 Apr 9. Citation on PubMed
  • Preisler N, Orngreen MC, Echaniz-Laguna A, Laforet P, Lonsdorfer-Wolf E, Doutreleau S, Geny B, Akman HO, Dimauro S, Vissing J. Muscle phosphorylase kinase deficiency: a neutral metabolic variant or a disease? Neurology. 2012 Jan 24;78(4):265-8. doi: 10.1212/WNL.0b013e31824365f9. Epub 2012 Jan 11. Citation on PubMed
  • Wuyts W, Reyniers E, Ceuterick C, Storm K, de Barsy T, Martin JJ. Myopathy and phosphorylase kinase deficiency caused by a mutation in the PHKA1 gene. Am J Med Genet A. 2005 Feb 15;133A(1):82-4. doi: 10.1002/ajmg.a.30517. Citation on PubMed
DNA helix

Genomic Location

The PHKA1 gene is found on the X chromosome.

Related Health Topics

  • Genes and Gene Therapy
  • Genetic Disorders

MEDICAL ENCYCLOPEDIA

  • Genes
  • Genetics

Understanding Genetics

  • What is DNA?
  • What is a gene?
  • What is a gene variant and how do variants occur?

Disclaimers

MedlinePlus links to health information from the National Institutes of Health and other federal government agencies. MedlinePlus also links to health information from non-government Web sites. See our disclaimer about external links and our quality guidelines.

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.

  • About MedlinePlus
  • What's New
  • Site Map
  • Customer Support
  • Subscribe to RSSRSS
  • Connect with NLM
  • NLM Web Policies
  • Copyright
  • Accessibility
  • Guidelines for Links
  • Viewers & Players
  • HHS Vulnerability Disclosure
  • MedlinePlus Connect for EHRs
  • For Developers
National Library of Medicine 8600 Rockville Pike, Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health
Last updated August 1, 2015
Return to top

Patients

  • Find a Clinic
  • Health Services
  • Complex Case Management
  • MA / Medicare Assistance

Quick Links

  • Billing Information
  • Careers
  • About Phynet
  • PhyNet News

Network Links

  • PrimeCareHomeHealth.com
  • PrimeCareNet.com
  • PrimeCareManagers.com
  • Core-Rehab.com

Home Office

4002 Technology Center Longview TX 75605
Phone: (903) 247-0484
Fax: (903) 247-0485
[email protected]
  • PrimeCareHomeHealth.com
  • PrimeCareNet.com
  • PrimeCareManagers.com
  • Core-Rehab.com
  • GET SOCIAL

© 2021 PhyNet Health • All rights reserved
YOUR LIFE. YOUR CHOICE.

TOP