Congenital hamartoma - most common benign paediatric cardiac tumour; average age at diagnosis »2 weeks[10,14]Affects ventricles and ventricular septum, large range of sizes 0.3-9 cm[1,14]Symptoms include murmurs, respiratory distress, ventricular inflow/outflow obstruction, and possible cardiogenic shock[9]Association with tuberous sclerosis; mutations of TSC1 and TSC2 genes; diagnostic: triad of seizures, mental retardation, and facial angiofibromas[1,2,11]Tumours may spontaneously regress. The gene discussed is TSC1; the disease is hamartoma.