We determined the concentrations of copper, the activities of ceruloplasmin and peptidylglycine alpha-amidating monooxygenase (PAM), and the stimulation index of PAM by the in vitro addition of copper in plasma samples obtained from three male patients with occipital horns and a milder Menkes disease phenotype, having severe copper deficiency due to the defect in copper transport.
This syndrome was similar to Menkes disease in some respects: X-linked recessive inheritance, marked psychomotor retardation with seizures, low serum copper and ceruloplasmin levels, and a block in gut copper absorption.