Variability in clinical expression of Menkes syndrome.

Six patients with Menkes syndrome are described, who differ from patients with the classical form of Menkes syndrome because of their longer survival; some of them also exhibited a milder manifestation of symptoms. Based on the present data and a summary of seven case reports describing Menkes patients with long survival, it may be possible to divide these patients into two subgroups: one group of severely affected patients with long survival and another group of very mildly affected patients with late onset of symptoms. Perhaps only the latter represents a true subgroup of Menkes syndrome. The possible benefits of copper therapy are discussed.