Two Cases of Danon Disease – A 'Cousin' of Pompe Disease

Danon disease, a rare X-linked cardiac and skeletal myopathy, was described in two boys aged 5 and 7 years who presented with weakness, fatigue, and elevated liver enzymes. Initially misdiagnosed with drug-induced and cryptogenic hepatitis, both boys exhibited arrhythmia and WPW syndrome. Their symptoms, including low hair growth, muscle pseudohypertrophy, and distinctive physical features, were not specific to Danon disease. The 7-year-old also showed aggressive behavior from age 4. These cases highlighted the diagnostic challenges due to non-specific symptoms and the importance of considering Danon disease in similar clinical presentations.