Postmortem Presentation and Review of Danon Disease: A Rare Metabolic Disorder.

Danon disease is a rare, X-linked dominant inherited lysosomal storage disorder that involves a mutation in the lysosomal-associated membrane Protein 2 gene. Mutation in this gene results in severe disease clinical manifestations that may include skeletal and cardiac myopathies, retinopathies, and intellectual disabilities. This case report explores postmortem findings observed in a 25-year-old male donor who succumbed to heart failure secondary to Danon disease. With no transplant history, postmortem findings include hypertrophy, extensive fibrosis, and vacuolization in cardiomyocytes compared with expected anatomical findings in an unaffected patient. This case report is aimed at deepening the understanding of the clinical manifestations of Danon disease, raise awareness, and explore diagnostic approaches and differentials to help identify additional treatment options that may improve patient outcomes.