ORC1 and Mungan syndrome: Recently, mutations in genes encoding the pre-RC components Orc1, Orc4, Orc6, Cdc6, and Cdt1 have been linked to Meier-Gorlin syndrome (MGS), a rare genetic disorder characterized by primordial dwarfism, small ears and aplastic or hypoplastic patella (Guernsey et al., 2011; Bicknell et al., 2011a, b).