APBD Research Foundation

Cycle 1

Web:

https://www.apbdrf.org/

Contact:

Adult Polyglucosan Body Disease (APBD) is a genetic disorder that results in the low activity of an important enzyme, Glycogen Branching Enzyme (GBE1), which is used to make glycogen. When there is low activity of this enzyme, newly formed glycogen is manufactured incorrectly into long strands called polyglucosan bodies. These polyglucosan bodies cannot be used for fuel and build up inside nerve cells. This causes damage to these nerves. The damage often results in numbness, and eventually weakness in the muscles controlled by these nerves.

Last updated 04/30/2026

Clinical

Disease Class

Cardiac diseases

Genetic diseases

Hepatic diseases

Inherited metabolic disorder

Leukodystrophies and white matter disorders

Multi-system genetic syndromes

Muscular and neuromuscular diseases

Neurological diseases

Ophthalmic diseases

Urogenital diseases

Body Systems

Cardiovascular / Circulatory

Digestive

Endocrine

Hematopoietic / Lymphatic / Immune

Metabolic

Muscular / Skeletal

Nervous / Sensory

Renal / Urinary / Excretory

Reproductive

Organs

Adrenal glands

Bladder

Blood

Brain

Eyes

Heart

Intestines

Liver

Lymph fluid, nodes, ducts, vessels

Muscles

Nerves

Prostate gland

Spinal cord

Stomach

Testes

Throat/pharynx

Known Genetic Link

Yes, one or more genes directly cause the condition

Causative Genes

GBE1

Contributory Genes

None specified / unknown

Type of Inheritance

Autosomal recessive

Newborn Screening

Disease Mechanism(s)

Carbohydrate metabolism defect

Enzyme deficiency

Glycogen-related defects

Age of Onset

Adolescence (12-17)

Adulthood (age 18-64)

Early childhood (age 1+-5)

Infancy (age 0-1)

Middle childhood (6-11)

Prebirth

Average Age at Diagnosis

Adulthood (age 18-64)

Early childhood (age 1+-5)

Infancy (age 0-1)

Life Expectancy

Elderly (age 65+)

Affected Sex(es)

Female

Male

National Prevalence

1001-10000

Global Prevalence

10000+

National Incidence

Unknown

Global Incidence

Unknown

Populations and/or ancestry with higher prevalence

Ashkenazi Jews

Symptoms / Phenotypes

balance problems

cognitive decline

dementia

fatigue

gait abnormalities / gait disturbance

muscle stiffness

muscle weakness

neurogenic bladder

orthostatic hypotension

paralysis

peripheral neuropathy

sexual dysfunction

spasticity

thermal dysregulation

vision problems

Biomarkers

Diagnostic

· GBE assay, genetic screening for GBE1 variants, MRI of brain and spinal cord

Existing Therapies

None

Therapies in Development

Antisense oligonucleotide (ASO) therapy

Devices/medical equipment

Dietary & metabolic therapies (medical food, dietary restriction, supplements, etc.)

Gene therapy

· AAV GBE1 replacement therapy

RNA interference (RNAi) therapy (siRNA, etc.)

Repurposed drug

Small molecule therapy (novel small molecule drugs)

· GHF201, GHF205

Surgical & interventional

Therapeutic Development Stages

IND/CTA submitted but not approved

In clinical trials (Phase I, II, III, or IV)

In preclinical development

In research/exploratory phase

Therapeutic Development Role

Access to registry or natural history study

Data analysis

Data sharing

Focus group participation or coordination

Funding

Meetings with regulators (e.g., FDA listening sessions, PFDD meetings)

Outcome measures development

Recruitment and outreach to patients

Recruitment and outreach to trial sites / physicians

Results dissemination (including publications)

Sample provision

Organizational & Research

Cell Lines

Fibroblasts

Lymphoblasts

Plasma

Cell Lines, Institution

COMBINEDBrain

Columbia University

Cell Lines, Involvement

Funded

Cell Lines, share

Disease Model

Mouse

Disease Model, Involvement

Funded

Disease Model, share

Organizational Challenges

research infrastructure development, therapeutic development, funding constraints

Clinical Trial Role

Data analysis

Data sharing

Focus group

Funding

Meeting with regulators

Outcome measures, development

Recruitment and outreach, patients

Recruitment and outreach, trial sites/physicians

Results dissemination, publication

Study material design, review (not protocol)

Study protocol design, review

Clinical Trial Types

Observational

Other

Phase 1

Biobank, Institution

COMBINEDBrain

Biobank, Involvement

Designed

Funded

Own

Center of Excellence, Institution

None

Registry

Yes, we have collaborated on a registry

Data Collected, Registry

Genetic data

Other

Patient contact info

Data Entered by, Registry

Both

Platform, Registry

REDCap

Natural History Study

Yes, we have collaborated on a natural history study

Data Collected, Natural History Study

Electronic health records/electronic medical records

Genetic data

Imaging data

Medication usage

Patient-reported data

Retrospective data

Platform, Natural History Study

REDCap

FDA Patient Listening Session

Yes

FDA Patient-Focused Drug Development (PFDD) Program

ICD Codes

We use an ICD-10 code capturing the family of diseases to which our disease belongs

Yes, we have an ICD-10 code specific to our exact disease

Diagnostic Guidelines

Yes, we have published formal guidelines in a peer-reviewed journal

Science Advisory Board Policies

No policies

Research Network Policies

Has CRN but no policies

Patient Priority Survey

Research Roadmap

Yes we have a Research Roadmap, and will share policies

None

Europe

None