Genetic studies in mice (Fotaki et al., 2002) and man (Bronicki et al., 2015; Courcet et al., 2012; Dang et al., 2017; DDD Study et al., 2017; Ji et al., 2015; Møller et al., 2008; van Bon et al., 2016; Yamamoto et al., 2011) have revealed that haploinsufficiency of DYRK1A can lead to severe disorders of brain development, including microcephaly, as well as a generalized developmental delay. Here, DYRK1A is linked to microcephaly.