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Danon Disease

Danon disease is a condition bearing similarities to GSD2 however the mutation occurs on a different gene (LAMP2). It has sometimes been called GSD2b.

Unlike both Infant Onset Pompe Disease (IOPD) and Late Onset Pompe Disease (LOPD), presentation is linked to gender and it is a dominant gene. Males are more severely affected by proximal skeletal muscle myopathy, cardiomyopathy and mild to moderate learning disabilities. Eyes can also be affected.

Prevalence is not well established, with only a handful of people diagnosed in the UK. There is a lack of robust information, partly due to the very low number of people affected.

Other names

Lysosomal glycogen storage disorder without acid-maltase deficiency

Pseudoglycogenosis II

Antopol disease



Inheritance X-linked dominant
Incidence Unknown
UK diagnosed About 5  (UK diagnosed explained)

More severe in males. Cardiomyopathy, learning disability, skeletal muscle weakness

Secondary symptoms

Cardiac arrhythmia, fatigue, mobility problems, breathlessness


None†. Biotech research into a treatment is ongoing.


Progressive. If cardiac symptoms worsen heart transplant can be considered.

† Patients would not benefit from the same enzyme replacement therapy (ERT) as commonly used for people with Pompe disease because they are not deficient in the same enzyme.

Sources of further information

There are two reliable sources of further information. Both of these websites are provided by American organisations.


The National Institutes of Health has information on Danon disease in its Genetics Home Reference Library.

Visit the Genetics Home Reference page on Danon disease.


The National Organisation for Rare Disorders (NORD) provides a comprehensive summary and information about a Danon disease registry.

Visit the Danon disease section of the NORD website.

Review of natural history and recent advances

This 2019 review surveys over 500 Danon disease patients reported in the literature from the first description to the present, and summarises the clinical, pathological and molecular data and treatment perspectives.

Cenacchi G, et al. Neuropathol Appl Neurobiol. 2019 Nov 7. doi: 10.1111/nan.12587.

Read the abstract and link to the paper.

A registry for Danon disease

A researcher in the Colorado-based Lysosomal storage disease centre, Dr Matthew Taylor, has developed a registry of Danon disease patients and families to collect information that may advance the understanding of this disease and be helpful in the future development of treatments.

Go to Dr Taylor’s Danon disease web site.

Gene therapy trial

A new gene therapy trial is opening in the USA for Danon disease. Rocket Pharmaceuticals Inc opened a Phase 1 clinical gene therapy trial in April 2019.

Go to the summary on the Clinical Trials web site.

Are you affected by Danon disease?

We can offer you support, help with advice and enable you to make connections for better information on this very isolating and rare condition. We can support you with accessing appropriate non-medical help.

Contact AGSD-UK via our “Message us” page.