ARID4B and obesity due to melanocortin 4 receptor deficiency: BCAA dysregulation is furthermore an increasingly recognized feature of diabetes mellitus, obesity, and heart failure, acquired disorders associated with an increased risk for arrhythmias and SCD.4–6,15–17,52 Our current observations suggest that enhanced BCAA plasma levels as observed in metabolic syndromes may underlie, at least in part, the increased susceptibility to cardiac arrhythmias and SCD observed in these patients, constituting a potential target for the prevention and treatment of cardiac arrhythmias in this setting.