Regression of massive left ventricular hypertrophy in Danon disease.

Danon disease is a rare X-linked multi-system lysosomal storage disorder. It may manifest as severe cardiomyopathy in affected individuals, with different clinical courses observed for men and women. Women may experience a hypertrophic or a dilated/hypokinetic phenotype irrespective of their disease stage. Men typically present earlier with progressive hypertrophy, and rapid regression of their hypertrophy with dilation and hypokinesis with onset of heart failure outcomes. In this case we demonstrate echocardiographic images of a young male taken just 2 years apart.