MCPH1 and autosomal recessive primary microcephaly: To date, at least 28 genes have been identified as causative genes of autosomal recessive primary microcephaly (MCPH), ranging from MCPH1 to MCPH28. Mutants of most of them have been established in animal models, such as zebrafish, Drosophila, mouse, and ferret [2]; however, behavioral analyses of these animal models are lacking.