COMT and Huntington disease: Of note, polymorphisms in the genes that code for monoamine oxidase A (MAOA) and catechol‐O‐methyltransferase (COMT) have been recently shown to act as modifiers of cognitive and psychiatric symptoms in a Danish HD population (Vinther‐Jensen et al, 2015), thus strengthening the link between MAOA activity, dopaminergic tone and cognitive and psychiatric manifestations of HD.