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Lysosomal storage diseases

Pompe disease (glycogen storage disease type II)

An inherited disease in which a sugar called glycogen builds up in the cells. It mainly affects the muscles. The type that begins in infancy is severe and also affects the heart.

Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source

Orphanet has a guideline for emergency doctors for this disease (language: French). See on Orphanet

Prepare an emergency card

This page is translated from the Turkish original.

This disease is followed through the “Lysosomal storage diseases” group.

Understanding the disease

This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.

What happens in this disease?

The body lacks an enzyme that breaks down glycogen. Glycogen is a type of sugar stored in cells. Glycogen builds up in cells to harmful levels. The muscles, the heart and the breathing muscles are affected most.

Which symptoms can occur?

The disease can begin in infancy or at a later age. The classic type, which begins in infancy, is the most severe. If it is not treated, it is life-threatening in the first year.

  • Marked muscle weakness and floppiness (in the classic type)
  • Enlarged heart and heart problems (in the classic type)
  • Difficulty feeding and not gaining weight
  • Breathing problems
  • Large liver (in some babies)
  • In the late type, slowly increasing weakness in the leg and trunk muscles
  • In the late type, there may also be breathing problems

How is it diagnosed?

For the diagnosis, enzyme activity is measured in blood or in a dried blood spot. A genetic test confirms the diagnosis. Heart, lung and muscle tests may also be done. In some places, it is also found through newborn screening.

Treatment and care

The main treatment is enzyme replacement therapy (giving the missing enzyme into a vein). If needed, breathing support is given. Physical therapy and nutritional support are also part of care. Different specialists follow the patient together. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

The disease is passed on through recessive inheritance. The child receives one changed gene from the mother and one from the father. The mother and father are often healthy carriers. Genetic counselling is recommended for brothers and sisters and for future pregnancies.

Source: MedlinePlus Genetics — Pompe disease · Orphanet — Glycogen storage disease due to acid maltase deficiency · NORD (National Organization for Rare Disorders) — Pompe disease

Key facts

How common is it?
Prevalence: 1-9 per 100 000 (Europe) · Birth prevalence: 1-9 per 1 000 000 (Europe)
How is it inherited?
Autosomal recessive
When does it usually start?
Before birth, Newborn period, Infancy, Childhood, Adolescence, Adulthood
Gene(s) involved
GAA

These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.

You are not alone: patient associations in Türkiye

Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.

For all rare diseases: Nadir Hastalıklar Federasyonu

Links checked on October 8, 2026.

Guides related to this disease

  • Home care and medical devices · Home health service, oxygen and respiratory device reports, wheelchairs and orthoses, power outage notification, emergency plan.

Support and help

Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.

News about Pompe

Clinical trials (ClinicalTrials.gov)

A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.

This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.

Questions you can ask your doctor

  • Could this trial be suitable for us?
  • If we take part, how would current treatment and check-ups be affected?
  • Where does the trial take place, and how are travel and accommodation handled?
  • What happens if we want to leave the trial?

ClinicalTrials.gov lists 24 active interventional studies for this disease. 10 are recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.

Selected records (studies with a site in Türkiye first):

See all studies on ClinicalTrials.gov · Joining clinical trials

Lysosomal storage diseases: other news

Medical codes (for talking with your doctor and finding sources)

These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.

Orphanet code: ORPHA:365

No separate ICD-11 code; WHO classifies this disease under: 5C51.3 (Glycogen storage disease)

Codes checked against WHO ICD-11 and Orphanet on October 6, 2026.

This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.

The information on these pages is for general information only and does not replace medical advice. Talk to your doctor about diagnosis and treatment decisions. In an emergency in Türkiye, call 112.

Every update is based on an open source and labeled with its level of evidence. No advertising and no drug brand names. Our scientific principles

This page was translated from Turkish by the Doktorclub editorial team.