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Health condition

Pompe disease in adults

Late-onset Pompe disease is a treatable inherited muscle disorder causing slowly progressive limb-girdle weakness and breathing muscle involvement - often mislabelled for years as another myopathy.

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against current NHS and UK specialist society guidance at the time of review.

  • 03

    Current for 2026

    Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.

Key facts

The essentials at a glance.

Which gene and test confirm it, who should be tested in the family, and which specialist to see.

  • Caused by GAA variants reducing acid alpha-glucosidase; autosomal recessive

  • Suspect it in adults with progressive hip and shoulder weakness, raised CK, or unexplained breathing problems lying flat

  • Diagnosis: a dried blood-spot enzyme test, confirmed by GAA genetic testing

  • Enzyme replacement therapy is available and works best before severe weakness develops

Understanding the condition

What it is and what happens next.

What causes it, how it is confirmed, and the testing and specialist routes available in the UK.

What it is and how it presents

The adult form of Pompe disease progresses quietly: difficulty climbing stairs or rising from chairs, a waddling gait, then breathlessness lying down as the diaphragm weakens, sometimes leading to respiratory failure before the diagnosis is made. Because it mimics limb-girdle muscular dystrophy and inflammatory myopathy, many patients pass through years of tests; a simple blood-spot enzyme assay is now recommended early in any unexplained limb-girdle weakness.

Testing, surveillance and specialist care

Once enzyme deficiency is shown, GAA sequencing confirms the diagnosis, and care moves to a specialist centre where enzyme replacement therapy, respiratory monitoring (including lying-and-standing vital capacity) and physiotherapy are coordinated. Siblings can be offered testing and genetic counselling. NHS clinical genetics services carry some of the longest waits in the health service, often many months for a first appointment, whereas private genetic testing and a specialist review can typically be arranged within around two weeks.

Seeing a specialist

Who to see, and how quickly you can be seen.

The specialist for this condition is usually a metabolic physician or neuromuscular neurologist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.

A quiet reminder

This guide is for information, not medical advice.

Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any emergency symptoms.

Frequently asked

Common questions about Pompe disease in adults.

Quick, plain-English answers to what people ask us most.

  • What is Pompe disease in adults?

    Pompe disease is a rare inherited metabolic disorder caused by a deficiency of an enzyme needed to break down glycogen, leading to progressive muscle weakness, including muscles used for breathing, in the adult-onset form.

  • What causes Pompe disease?

    It's caused by inherited mutations in the GAA gene, resulting in deficiency of the enzyme acid alpha-glucosidase, which leads to abnormal glycogen accumulation within muscle cells, gradually impairing their function.

  • What are the symptoms in adults?

    Progressive limb-girdle muscle weakness (affecting the hips and shoulders), difficulty climbing stairs or rising from a chair, and, often more seriously, weakness of the breathing muscles, sometimes noticed as morning headaches or disturbed sleep, are typical.

  • Is adult-onset Pompe disease serious?

    Yes, it's a progressive condition that can significantly affect mobility and breathing over time, though it generally progresses more slowly than the severe infantile form of the disease.

  • Is Pompe disease hereditary?

    Yes, it's an inherited genetic condition, passed on in an autosomal recessive pattern, meaning both parents typically carry one copy of a faulty gene without being affected themselves.

  • Can Pompe disease be treated?

    Yes, enzyme replacement therapy can help slow disease progression and improve or stabilise muscle and breathing function in many adult patients, alongside physiotherapy and respiratory support as needed.

  • How is Pompe disease diagnosed?

    A blood test measuring the deficient enzyme's activity, confirmed with genetic testing for GAA mutations, establishes the diagnosis, sometimes alongside muscle biopsy findings.

  • How long does treatment take to show benefit?

    Enzyme replacement therapy is typically given as regular infusions long-term, with benefits on muscle strength and breathing function often becoming apparent over months of consistent treatment.

  • Pompe disease vs muscular dystrophy — what's the difference?

    Muscular dystrophies are a different group of inherited muscle conditions with various genetic causes, while Pompe disease is specifically caused by this enzyme deficiency and glycogen accumulation; specific enzyme and genetic testing distinguishes Pompe disease from other muscle weakness conditions.

  • When should I see a specialist, and how quickly can I be seen privately?

    See a neurologist if you have progressive limb weakness or unexplained breathing difficulty, particularly with a relevant family history. Private specialist assessment is typically available within about two weeks, faster than standard NHS pathways for this rare condition.