GMNN and Meier-Gorlin syndrome: Notably, the phenotype for this group of genes appears distinct from Meier-Gorlin syndrome (a form of microcephalic dwarfism with microtia and patella hypoplasia/aplasia), which is caused by mutations in genes encoding the pre-replication (PRE-RC) components ORC1,4,6, Cdc6, and Cdt1; Geminin, and the pre-initiation complex (PRE-IC) component CDC45 (Bicknell et al., 2011a, Bicknell et al., 2011b, Fenwick et al., 2016, Guernsey et al., 2011).