Fibroblast cultures from 12 unrelated patients with classical Menkes disease, an X-linked disorder of copper metabolism, were analyzed for mutations in the MNK gene at the Howard Hughes Medical Institute, University of California, San Francisco. Mutations were observed in 10 patients. Southern blot hybridization and reverse transcription-PCR should identify mutations in the majority of patients. 
COMMENT. The authors conclude that these studies should help to clarify the role of mutations leading to mild and atypical cases of Menkes disease, X-linked cutis laxa, and classical Menkes disease. Partial gene deletions have been observed in 15 - 20% of patients with Menkes disease. The majority of patients have the severe, classical symptoms of a progressive neurologic degeneration, connective-tissue defects, hypopigmentation, kinky hair, and death in early childhood. A deficiency of copper-containing enzymes results from a defect in copper transport.