Meier-gorlin syndrome

Abstract

Proteins required for the earliest stages of the initiation of DNA replication, including the origin recognition complex, Cdc6, Cdt1, and the Mcm2-7 proteins, cooperate to assemble pre-replicative complexes at all origins of DNA replication prior to the actual start of DNA synthesis from each origin during S phase of the cell division cycle. These initiation proteins are also involved in processes at centrosomes and centromeres during mitosis that ensure the correct segregation of the duplicated sister chromatids after DNA replication. Rare, recessive mutations in genes encoding some of these proteins result in Meier-Gorlin syndrome (MGS), characterized by microcephaly and primordial dwarfism, but normal intelligence. Biochemical and cell biology studies show that MGS mutations affect DNA replication, but some mutations affect both DNA replication and chromosome segregation. The observations have implications related to control of tissue and body size.