To the Editor: In the October 10 issue, Zoghbi et al. presented an interesting article on reduction of biogenic amine levels in the Rett syndrome.1 From the clinical description of the six patients studied by Dr. Zoghbi and his colleagues one is forced to conclude that the patients suffered from a syndrome other than the Rett syndrome. The original article by Rett2 reported that every one of his 22 patients suffered from substantial hyperammonemia, a feature that was not present in any of the patients of Zoghbi et al. As Professor Rett stated in his summary, the syndrome that he. © 1986, Massachusetts Medical Society. All rights reserved.