Interestingly, whereas wide deletions in the Atp7a gene in mouse mutant males have a prenatal lethal effect, in humans about 15% of the mutations in the ATP7A gene, which are caused by large deletions, in great majority result in the classical, severe form of Menkes disease leading to death in early childhood (<6 years; Poulsen et al., 2002; Tümer et al., 2003). Here, ATP7A is linked to Menkes disease.