Menu
Recruiting NCT04454216

GSD VI and GSD IX Natural History

— Observational Glycogen Storage Disease VI GLYCOGEN STORAGE DISEASE IXa1 GLYCOGEN STORAGE DISEASE IXa2 Glycogen Storage Disease IXB

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: No intervention.
Who it may be relevant to
Registry conditions: Glycogen Storage Disease VI, GLYCOGEN STORAGE DISEASE IXa1, GLYCOGEN STORAGE DISEASE IXa2, Glycogen Storage Disease IXB. Basic parameters: 0 years — 90 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
United States
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

Unsure about the terms? Read our patient guide →

Overview

Collection and review of clinical information related to Glycogen Storage Disease Type VI (GSD VI) OR Glycogen Storage Disease Type IX (GSD IX) generated during clinic visits.

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.

Interventions

  • Other No intervention
    This is an observational study that consists of data abstraction from patient medical records.

Primary outcome measures

  • Progression of disease confirmed by medical record review [Time frame: through study completion, an average of 10 years]
  • Serum biotinidase activity [Time frame: through study completion, an average of 10 years]
  • Number of genotypes presented [Time frame: through study completion, an average of 10 years]
  • Number of phenotypes presented [Time frame: through study completion, an average of 10 years]

Eligibility criteria

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). 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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model
Cohort

Study locations

United States · 1 center
  • Duke University — Durham

Publications

  • Koch RL, Fares AH, Cocanougher BT, Lim J, Haijer-Schreuder AB, Derks TGJ, Grunert SC, Sharma R, Jones KA, Kishnani PS. PHKA1-associated phosphorylase kinase deficiency: a monogenic disorder of exercise intolerance and myalgia. NPJ Genom Med. 2025 Nov 10;10(1):71. doi: 10.1038/s41525-025-00527-y. PMID 41213961

Identifiers

NCT: NCT04454216 · Pro00104116

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗