GSD VI and GSD IX Natural History | NCT04454216

Studies
GSD VI and GSD IX Natural History

NCT04454216

Sponsor

Duke University

Status

Recruiting

Last Update Posted

May 5, 2026Actual

Enrollment

400Estimated

Phase

Not provided

Conditions

Glycogen Storage Disease VI
GLYCOGEN STORAGE DISEASE IXa1
GLYCOGEN STORAGE DISEASE IXa2
Glycogen Storage Disease IXB
Glycogen Storage Disease IXC
GSD 9 (All Subtypes)
GSD 6

Interventions

No intervention

Countries

United States

Protocol Section

Identification Module Status Module Sponsor/Collaborators Module Oversight Module Description Module Conditions Module Design Module Arms/Interventions Module Outcomes Module Eligibility Module Contacts/Locations Module References Module IPD Sharing Statement Module

Results Section

Participant Flow Module Baseline Characteristics Module Outcome Measures Module Adverse Events Module More Info Module

Annotation Section

Annotation Module

Document Section

Large Document Module

Derived Section

Miscellaneous Info Module Condition Browse Module Intervention Browse Module

Protocol Section

Identification Module

NCT ID

Results Section

No data available

No data is available for this block.

Annotation Section

No data available

No data is available for this block.

Document Section

No data available

No data is available for this block.

Derived Section

Miscellaneous Info Module

Version Holder

Status Module

Record Verification Date

May 2026

Overall Recruitment Status or Expanded Access Status

Recruiting

Last Known Status

Not provided

Delayed Posting

Not provided

Why Stopped

Not provided

Expanded Access Info

Start Date

Sep 18, 2020Actual

Primary Completion Date

Jan 1, 2030Estimated

Completion Date

Jan 1, 2030Estimated

First Submitted Date

Jun 29, 2020

First Submission Date that Met QC Criteria

Jun 29, 2020

First Posted Date

Jul 1, 2020Actual

Results Waived

Not provided

Results First Submitted Date

Not provided

Results First Submitted that Met QC Criteria

Not provided

Results First Posted Date

Not provided

Certification/Extension (aka Delayed Results) First Submitted Date

Not provided

Certification/Extension First Submitted that Passed QC Review

Not provided

Certification/Extension First Posted Date

Not provided

Last Update Submitted Date

May 4, 2026

Last Update Posted Date

May 5, 2026Actual

Oversight Module

Has Data Monitoring Committee (DMC)

Is FDA Regulated Drug

Is FDA Regulated Device

Is Unapproved Device

Not provided

Pediatric Postmarket Surveillance of a Device Product

Not provided

Product Exported from US

Not provided

FDAAA801 Violation

Not provided

Description Module

Brief Summary

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.

Design Module

Study Type

Observational

Number of References to an Expanded Access Study

Not provided

Expanded Access Types

Not provided

Patient Registry

Yes

Target Follow-Up Duration

20 Years

Phases

Not provided

Interventional Study Design

Allocation

Not provided

Intervention Model

Biospecimen

No data available

No data is available for this block.

Enrollment

400Estimated

Arms/Interventions Module

Arm Groups

Not provided

Interventions

Name	Type	Description	Arm Group Labels	Other Names
No intervention	Other	This is an observational study that consists of data abstraction from patient medical records.

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
Progression of disease confirmed by medical record review		through study completion, an average of 10 years
Serum biotinidase activity		through study completion, an average of 10 years
Number of genotypes presented		through study completion, an average of 10 years
Number of phenotypes presented		through study completion, an average of 10 years

Secondary Outcomes

Not provided

Other Outcomes

Not provided

Eligibility Module

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

Accepts Healthy Volunteers

Sex

All

Sex/Gender Based

Not provided

Sex/Gender Description

Not provided

Minimum Age

0 Years

Maximum Age

90 Years

Standard Ages

ChildAdultOlder Adult

Study Population

All patients with GSD VI or GSD IX, regardless of gender or ethnicity, are eligible for enrollment.

Sampling Method

Non-Probability Sample

Contacts/Locations Module

Central Contacts

Name	Role	Phone	Extension	Email
Rebecca L Koch, PhD, RDN	Contact	919-681-8823		rebecca.koch@duke.edu
Nisha Dalal, M.S. CCC-SLP	Contact	919-668-3107		nisha.dalal@duke.edu

Overall Officials

Name	Affiliation	Role
Priya Kishnani, MD	Duke University	Principal Investigator

Locations

Facility	Status	City	State	ZIP	Country	Contacts
Duke University	Recruiting	Durham	North Carolina	27710	United States

References Module

Citations

PubMed Identifier	Type	Citation	Retractions
41213961	Derived	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.

ID	Term
D006013	Glycogen Storage Disease Type VI
C567579	Glycogen Storage Disease, Type IXA2
C563008	Glycogen Storage Disease IXB
C567809	Glycogen Storage Disease IXC

ID	Term
D006008	Glycogen Storage Disease
D002239	Carbohydrate Metabolism, Inborn Errors
D008661	Metabolism, Inborn Errors
D030342	Genetic Diseases, Inborn