Abstract
Danon disease (DD) is a rare, X-linked genetic disorder caused by LAMP2 deficiency. Clinical phenotype involves early cardiomyopathy development along with pre-excitation, skeletal myopathy, retinopathy, and cognitive impairment. We highlight how a noninvasive diagnostic approach based on clinical and imaging red flags for DD can be employed to raise high clinical suspicion for DD, which was confirmed by genetic testing results. (Level of Difficulty: Intermediate.).