Menkes disease: A biochemical abnormality in cultured human

Cultured skin fibroblasts from patients with Menkes disease, an X-linked disorder involving a defect in copper metabolism, were analyzed for copper concentration by means of atoinic absorption spectrophotometry. These cultures consistently exhibited elevated copper concentra- tions (mean = 335.5 ng of copper per mg of protein) when compared to control fibroblast cultures (mean = 59.2 ng of copper per mg of protein). External factors that could influ- ence the copper content of cultures were found not to affect the differences in copper concentration between control and Menkes cells. Furthermore, Menkes cells could be differen- tiated from cultured fibroblasts of controls, of presumed het- erozygotes, and of Wilson's disease patients by copper con- centration. These observations led to the conclusion that the increased copper content of cultured Menkes cells was char- acteristic of Menkes disease, resulting from the expression of the genetic abnormality. This provides a genetic marker, a defect in metal metabolism demonstrated in human fibro- blasts, that should prove valuable in both the diagnosis of Menkes disease and in the study of the fundamental defect of this genetic disorder.