RBCK1 and cardiomyopathy: HOIL‐1 deficiency is associated with severe primary immunodeficiency, cardiomyopathy and muscle weakness (Boisson et al, 2012; Nilsson et al, 2013; Wang et al, 2013), of which there is no evidence in ORAS patients (Damgaard et al, 2016; Zhou et al, 2016).