However, a variety of inherited and de novo mutations in CLCN4, which in humans is located X-chromosomal in contrast to the autosomal positioning of the Clcn4 gene in the laboratory mouse Mus musculus (Palmer et al., 1995; Rugarli et al., 1995), have recently been identified in patients with intellectual disability, epilepsy and behavior disorders, but lacking neurodegeneration (Veeramah et al., 2013; Hu et al., 2016; Palmer et al., 2018; Zhou et al., 2018). The gene discussed is CLCN4; the disease is epilepsy.