What is Danon disease?
Danon disease is a rare condition that causes cardiomyopathy, the weakening of skeletal muscles, and intellectual disabilities. Males with this disease experience an earlier onset and more severe symptoms than females.
What are the symptoms of Danon disease?
The three characteristic symptoms of Danon disease are cardiomyopathy, the weakening of the skeletal muscles, and intellectual disabilities, but males see more severe symptoms than females.
The cardiomyopathy that comes from this condition is either dilated or hypertrophic. Both types have the potential to cause heart failure. All males who have Danon disease experience cardiomyopathy, and the majority of females are also affected.
The weakening of skeletal muscles is present in the majority of males and about half of females. The upper arms, shoulders, neck, and upper thighs are the most commonly affected muscles. Males may also have high levels of the enzyme creatine kinase, which indicates muscle disease.
Intellectual disability is present in the majority of males with Danon disease, but only a small portion of the females are affected by this symptom.
People may also experience other symptoms, such as gastrointestinal disease, breathing problems, visual abnormalities, heart palpitations, arrhythmia, chest pain, and cardiac preexcitation.
What causes Danon disease?
Mutations in the LAMP2 gene are responsible for Danon disease. These mutations affect the LAMP-2 protein, which is associated with lysosomal function. Its exact job is unknown, but it is suspected that autophagic vacuoles accumulate in the muscle cells due to a lack of the LAMP-2 protein, which then leads to muscle weakness.
Danon disease is inherited in an X-linked dominant pattern.
How is Danon disease diagnosed?
Due to the rarity of this disease, a diagnosis can take time, as many medical professionals do not have experience with it. A family and medical history are necessary for a diagnosis. A skeletal muscle or heart biopsy are tests that can lead to a diagnosis of Danon disease. A confirmation is obtained through genetic testing.
What are the treatments for Danon disease?
Treatment for this condition is symptomatic. A team of specialists should be assembled for the best possible treatment.
In terms of cardiomyopathy, heart medications should be prescribed for the treatment of heart disease when necessary. Heart transplants and defibrillator implants are more options for cardiac treatment.
Physical therapy is used as treatment of muscle weakness. In terms of intellectual disabilities, educational interventions should occur when necessary. Eye exams are recommended so that any abnormalities in vision can be diagnosed early.