Disease is a rare genetic condition causing muscle weakness (muscular dystrophy), heart disease (cardiomyopathy), and mental
retardation (or learning problems).
Danon Disease was first described in 1981, and affects males more severely
than females. Boys will often develop symptoms in childhood or adolescence, while in females the symptoms may not be apparent
until adolescence or adulthood. Although males have an earlier and more rapidly progressive disease, serious medical problems
can occur in females.
The disease is NOT well-understood and physicians are largely unfamiliar with Danon Disease.
In fact, most physicians probably had not even heard of Danon Disease. We (the medical commmunity) do not yet know how many
people and families are affected with Danon Disease.