AP1S1 and MEDNIK syndrome: MEDNIK syndrome, also known as “syndrome de Kamouraska” (syndrome from Kamouraska), is a genetic disorder that is caused by mutations in adaptor related protein complex 1 subunit sigma 1 (AP1S1) and beta 1 (AP1B1) genes (Alsaif et al. 2019; Martinelli and Dionisi-Vici 2014).