Hypertrophic Cardiomyopathy - HCM - LAMP2
A subset of familial HCM patients with conduction abnormalities particularly progressive atrioventricular block, Wolff-Parkinson-White syndrome (WPW) and atrial fibrillation have been attributed to mutations in the genes encoding the γ2 regulatory subunit of adenosine monophosphate (AMP)-activated protein kinase (PRKAG2) and lysosome-associated membrane protein 2 (LAMP2). AMP-activated protein kinase (AMPK) functions in the regulation of gene expression, ion channel gating kinetics and key metabolic pathways including glucose metabolism.
in LAMP2 are responsible for Danon disease, an X-linked dominant lysosomal glycogen storage disease characterized by a triad of hypertrophic cardiomyopathy, skeletal myopathy and mental retardation. Skeletal myopathy is mild in most cases and can easily be overlooked. WPW is present in 35% of cases and mental retardation is seen in 70%. A dilated cardiomyopathy phenotype is sometimes observed. Affected males are usually symptomatic before the age of 20 with generally poor prognosis; female carriers develop cardiomyopathy later in adulthood. Pathologic analysis shows autophagic vacuoles containing glycogen.