GSD VI and GSD IX Natural History

Duke University (Other)
Overall Status
Recruiting ID

Study Details

Study Description

Brief Summary

A natural history study on Glycogen Storage Disease Type VI (GSD VI) and Glycogen Storage Disease Type IX (GSD IX)

Detailed Description

This natural history study will serve as a repository of clinical, laboratory, and biochemical information on individuals with GSD VI or GSD IX. This information will allow a more definitive description of glycogen phosphorylase (GP) and phosphorylase kinase (PhK) deficiency to be developed, which will permit development of treatment strategies for these diseases.

Duke will be the only site where this study takes place. However, since these are rare disorders, participants who receive care at other institutions will be included. The investigators will collect retrospective data from patient charts on diagnosed individuals, as far back as necessary to capture the clinical course of the disorder. Prospective data collected from patient charts after enrollment will be captured as well. Participant's medical records will be continually reviewed for the duration of the study.

Data will be collected from medical records and will only pertain to clinically relevant information, including, but not limited to: demographic and diagnostic information, tissue biopsy results, medical and family history, review of systems, imaging studies, results of liver and/or muscle testing, and urine and blood laboratory results.

Study Design

Study Type:
Observational [Patient Registry]
Anticipated Enrollment :
100 participants
Observational Model:
Time Perspective:
Official Title:
GSD VI and GSD IX Natural History
Actual Study Start Date :
Sep 18, 2020
Anticipated Primary Completion Date :
Apr 1, 2030
Anticipated Study Completion Date :
Apr 1, 2030

Outcome Measures

Primary Outcome Measures

  1. Progression of disease confirmed by medical record review [through study completion, an average of 10 years]

  2. Serum biotinidase activity [through study completion, an average of 10 years]

  3. Number of genotypes presented [through study completion, an average of 10 years]

  4. Number of phenotypes presented [through study completion, an average of 10 years]

Eligibility Criteria


Ages Eligible for Study:
0 Years to 90 Years
Sexes Eligible for Study:
Accepts Healthy Volunteers:
Inclusion Criteria:
  • Diagnosis of GSD VI or GSD IX via:

  • Two variants in the PYGL, PHKA1, PHKA2, PHKG1, PHKG2, or PHKB gene (or one variant with evidence of disease that is pathogenic, as confirmed by clinician). Note: for males, one variant in the PHKA1 or PHKA2 gene is sufficient for inclusion.

  • Deficient GP activity or PhK activity per enzymology

  • Histology as confirmed by clinician

  • Pregnant women with a diagnosis of GSD VI or GSD IX will be included

  • Able to provide informed consent for self (adults) or affected individual (minor or adults with a legally authorized representative)

  • Able to provide consent for release of medical records

Exclusion criteria:
  • Unable to provide informed consent for participation for one's self or by legally authorized representative/legal guardian/parent

Contacts and Locations


Site City State Country Postal Code
1 Duke University Durham North Carolina United States 27710

Sponsors and Collaborators

  • Duke University


  • Principal Investigator: Priya Kishnani, MD, Duke University

Study Documents (Full-Text)

None provided.

More Information


None provided.
Responsible Party:
Duke University Identifier:
Other Study ID Numbers:
  • Pro00104116
First Posted:
Jul 1, 2020
Last Update Posted:
Jul 29, 2022
Last Verified:
May 1, 2022
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD:
Studies a U.S. FDA-regulated Drug Product:
Studies a U.S. FDA-regulated Device Product:
Additional relevant MeSH terms:

Study Results

No Results Posted as of Jul 29, 2022