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.
Lysosomal glycogen storage disorder without acid-maltase deficiency
|UK diagnosed||About 5 (UK diagnosed explained)|
More severe in males. Cardiomyopathy, learning disability, skeletal muscle weakness
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.
The National Organisation for Rare Disorders (NORD) provides a comprehensive summary and information about a Danon disease registry.
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.
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.
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.