Danon disease is a genetic X-linked dominant disorder. The disease is linked to genetic defects in the lysosome-associated membrane protein 2 (LAMP2) gene, encoding the LAMP2 protein.

Due to the progression of heart failure, a heart transplant was suggested. However, the patient's parents delayed clearance, and the patient died from heart failure.

After death, genetic analysis and biopsy were obtained. Both studies confirmed Danon disease. The patient had a mutation of the gene LAMP2 (OMIM 309060) c.928G> A in the heterozygous state,
leading to amino acid substitution p.V310I.