Markedly reduced activity of lysyl oxidase in skin and aorta from a patient with Menkes' disease showing unusually severe connective tissue manifestations.

In Menkes' disease, a severe disturbance of copper handling appears to render copper unavailable for copper-requiring processes. We have measured the activity of lysyl oxidase, the copper-dependent enzyme that initiates the cross-linking of collagen and elastin, in extracts of skin and aorta obtained at autopsy from a patient with unusually marked connective tissue manifestations, and found it to be only 6-12% of normal, thus suggesting a basis for these alterations.