Overview
Glycogen storage disease due to acid maltase deficiency, juvenile onset — also commonly known as juvenile-onset Pompe disease or late-onset Pompe disease — is a rare inherited metabolic condition. This disease is caused by a shortage of an enzyme called acid alpha-glucosidase (also called acid maltase), which is needed to break down glycogen (a stored form of sugar) inside cells. When this enzyme does not work properly, glycogen builds up in cells, especially in muscles, causing progressive damage over time. In the juvenile-onset form, symptoms typically appear in childhood or adolescence, usually between ages 1 and 18. The most noticeable problems involve the muscles. Children may have trouble keeping up with peers physically, experience progressive weakness in the legs and trunk, and may develop breathing difficulties because the muscles that help with breathing are also affected. Unlike the severe infantile form, the heart is usually not significantly enlarged in the juvenile form, though the disease still has a major impact on quality of life. The treatment landscape has improved significantly since enzyme replacement therapy (ERT) became available. ERT helps replace the missing enzyme and can slow disease progression. Supportive care, including physical therapy and respiratory support, also plays an important role. Note: This Orphanet entry is marked as 'OBSOLETE' because the classification has been updated; juvenile-onset Pompe disease is now generally grouped under 'late-onset Pompe disease' in current medical terminology.
Also known as:
Key symptoms:
Progressive muscle weakness, especially in the legs and hipsDifficulty climbing stairsTrouble running or keeping up with other childrenBreathing difficulties, especially during sleep or when lying downFrequent respiratory infectionsFatigue and low energyDifficulty getting up from the floorWaddling gait or walking on toesEnlarged liver in some casesMuscle pain or crampsScoliosis or spine curvatureDifficulty swallowing in some casesMorning headaches from poor nighttime breathingDelayed motor milestones compared to peers
Autosomal recessive
Passed on when both parents carry the same gene change; often skips generations
Juvenile
Begins in the teen years
Treatments
No FDA-approved treatments are currently listed for OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset.
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Rare Disease Specialist
Treatment Centers
8 centersKobe University Hospital
📍 Kobe, Hyōgo
👤 Masaaki Mori, MD
Stanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🏥 NORDBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
Travel Grants
No travel grants are currently matched to OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset.
Community
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Start the conversation →Latest news about OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset
Disease timeline:
New trial: A Study of Anakinra in Japanese Patients With Still's Disease (SJIA and AOSD)
Phase PHASE3 trial recruiting. Anakinra
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
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Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.How severe is my child's enzyme deficiency, and what does that mean for how the disease may progress?,When should we start enzyme replacement therapy, and what can we expect from treatment?,How often should lung function and muscle strength be tested?,What physical activities are safe, and should we work with a physical therapist?,Are there any clinical trials or new treatments we should consider?,What signs of worsening should prompt an urgent visit or emergency care?,Should other family members be tested for carrier status or the disease itself?
Common questions about OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset
What is OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset?
Glycogen storage disease due to acid maltase deficiency, juvenile onset — also commonly known as juvenile-onset Pompe disease or late-onset Pompe disease — is a rare inherited metabolic condition. This disease is caused by a shortage of an enzyme called acid alpha-glucosidase (also called acid maltase), which is needed to break down glycogen (a stored form of sugar) inside cells. When this enzyme does not work properly, glycogen builds up in cells, especially in muscles, causing progressive damage over time. In the juvenile-onset form, symptoms typically appear in childhood or adolescence, us
How is OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset inherited?
OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset follows a autosomal recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset typically begin?
Typical onset of OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset is juvenile. Age of onset can vary across affected individuals.
Which specialists treat OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset?
1 specialists and care centers treating OBSOLETE: Glycogen storage disease due to acid maltase deficiency, juvenile onset are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.