Overview
Danon disease is a rare genetic condition that mainly affects the heart, muscles, and eyes. It is sometimes called LAMP2 deficiency or glycogen storage disease type IIb. The disease is caused by changes in a gene called LAMP2, which provides instructions for making a protein that helps cells clean up and recycle waste materials. When this protein is missing or does not work properly, harmful materials build up inside cells, especially in heart and muscle cells. The most serious effect of Danon disease is on the heart. Most people develop a very thick heart muscle (called hypertrophic cardiomyopathy), which can lead to heart failure or dangerous heart rhythm problems. Muscle weakness is also common, making everyday activities harder over time. Many people also experience vision problems and some have intellectual disability or learning difficulties. Danon disease affects males and females differently because of how it is inherited. Males tend to have more severe symptoms and develop them earlier in life, often in childhood or teenage years. Females may have milder symptoms that appear later. There is currently no cure, but treatments focus on managing heart problems, supporting muscle function, and improving quality of life. Heart transplant has been used in severe cases and can significantly extend life.
Also known as:
Key symptoms:
Thickened heart muscle (hypertrophic cardiomyopathy)Heart failureIrregular or dangerously fast heartbeat (arrhythmia)Muscle weakness in the arms and legsDifficulty with physical exercise or tiring easilyVision problems, including pigment changes in the retinaIntellectual disability or learning difficulties (more common in males)Liver enlargementFainting or near-fainting episodesShortness of breathChest pain or discomfortSwelling in the legs or ankles due to heart problems
Clinical phenotype terms (6)— hover any for plain English
X-linked dominant
Carried on the X chromosome; a single copy can cause the condition
Variable
Can begin at different ages, from infancy through adulthood
FDA & Trial Timeline
3 eventsRocket Pharmaceuticals Inc. — PHASE2
Chinese Academy of Medical Sciences, Fuwai Hospital — NA
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Danon disease.
3 clinical trialsare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Rare Disease Specialist
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 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
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Danon disease.
Community
No community posts yet. Be the first to share your experience with Danon disease.
Start the conversation →Latest news about Danon disease
Disease timeline:
New trial: Precision Diagnosis and Risk Stratification of Rare Cardiomyopathies Based on Novel Cardiac Magnetic
Phase NA trial recruiting.
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
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 heart involvement right now, and what signs should I watch for that mean it is getting worse?,Should I have an ICD implanted, and what are the risks and benefits for my situation?,At what point would you recommend a heart transplant evaluation?,Are there any clinical trials for gene therapy or other new treatments that I might qualify for?,Should my family members be tested for Danon disease, and who is most at risk?,What physical activities are safe for me, and are there any I should avoid?,What support services are available to help with school, work, or daily living?
Common questions about Danon disease
What is Danon disease?
Danon disease is a rare genetic condition that mainly affects the heart, muscles, and eyes. It is sometimes called LAMP2 deficiency or glycogen storage disease type IIb. The disease is caused by changes in a gene called LAMP2, which provides instructions for making a protein that helps cells clean up and recycle waste materials. When this protein is missing or does not work properly, harmful materials build up inside cells, especially in heart and muscle cells. The most serious effect of Danon disease is on the heart. Most people develop a very thick heart muscle (called hypertrophic cardiomy
How is Danon disease inherited?
Danon disease follows a x-linked dominant inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
Are there clinical trials for Danon disease?
Yes — 3 recruiting clinical trials are currently listed for Danon disease on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Danon disease?
19 specialists and care centers treating Danon disease are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.