brain sciences Review Molecular Genetics of Microcephaly Primary Hereditary: An Overview Nikistratos Siskos † , Electra Stylianopoulou †, Georgios Skavdis and Maria E. Grigoriou * Department of Molecular Biology & Genetics, Democritus University of Thrace, 68100 Alexandroupolis, Greece;
[email protected] (N.S.);
[email protected] (E.S.);
[email protected] (G.S.) * Correspondence:
[email protected] † Equal contribution. Abstract: MicroCephaly Primary Hereditary (MCPH) is a rare congenital neurodevelopmental disorder characterized by a significant reduction of the occipitofrontal head circumference and mild to moderate mental disability. Patients have small brains, though with overall normal architecture; therefore, studying MCPH can reveal not only the pathological mechanisms leading to this condition, but also the mechanisms operating during normal development. MCPH is genetically heterogeneous, with 27 genes listed so far in the Online Mendelian Inheritance in Man (OMIM) database. In this review, we discuss the role of MCPH proteins and delineate the molecular mechanisms and common pathways in which they participate. Keywords: microcephaly; MCPH; MCPH1–MCPH27; molecular genetics; cell cycle 1. Introduction Citation: Siskos, N.; Stylianopoulou, Microcephaly, from the Greek word µικρoκεϕαλi´α (mikrokephalia), meaning small E.; Skavdis, G.; Grigoriou, M.E. head, is a term used to describe a cranium with reduction of the occipitofrontal head circum- Molecular Genetics of Microcephaly ference equal, or more that teo standard deviations