MEDNIK syndrome - which of the following is true

A rare multisystem disorder of copper metabolism with features of both Menke's and Wilson's diseases has been repoed. It is termed the MEDNIK (mental retardation, enteropathy, deafness, neuropathy, ichthyosis, keratodermia) syndrome and is caused by mutations in the AP1S1 gene, which encodes an adaptor protein necessary for intracellular trafficking of copper pump proteins ATP7A (Menke's disease) and ATP7B (Wilson's disease).