TMEM43 and Arrhythmia: Molecular studies have demonstrated that the TMEM43 S358L causes impaired cardiac function or a fatal arrhythmia as result of increased nuclear stiffness, perturbed N-linked glycosylation with accumulation of mutant TMEM43 S358L protein in the nuclear envelope, and decreased conduction velocity at the intercalated discs of cardiac myocytes, which disrupt cell–cell connections, and localization and trafficking of proteins [21,34,92].