Menkes disease is an X-linked multisystem disorder with epilepsy, kinky hair, and neurodegeneration caused by mutations in the copper transporter ATP7A. Other ATP7A mutations have been linked to juvenile occipital horn syndrome and adult-onset hereditary motor neuropathy.1,2 About 5%–10% of the patients present with “atypical Menkes disease” characterized by longer survival, cerebellar ataxia, and developmental delay.2 The intracellular copper transport is regulated by 2 P type ATPase copper transporters ATP7A and ATP7B. This evidence concerns the gene ATP7A and Global developmental delay.