A case of ornithine transcarbamylase deficiency with Rett syndrome manifestations.

We have studied an 8-year-old girl with ornithine transcarbamylase deficiency with many of the manifestations of Rett syndrome. She is profoundly mentally retarded and microcephalic after normal development in early childhood. Seizures, hyperventilation, ataxia, amimia, and "hand wringing" stereotypies are present. The distinguishing characteristic is the history of recurrent episodes of vomiting and hyperammonemic coma. This case points to the possible existence of genocopies of Rett syndrome.