Ultrastructural study of enteric ganglia in three patients with Rett syndrome.

In order to verify whether a pseudo-obstruction syndrome was associated with morphological changes in enteric ganglia, we performed an ultrastructural study on rectal biopsy specimens in three patients with Rett syndrome. Features of enteric neurons, detected to a different extent in all three biopsy specimens, included an abnormal dilatation of endoplasmic reticulum with a disorganization of cisternae of the Golgi apparatus, and masses of unidentified electron-dense granulo-filamentous material, probably of lipidic origin, observed in the perikaryon. Large electron-lucent membrane-bound vacuoles were found mostly within satellite glial cells. Sometimes, the axon terminals were swollen and showed intraxonal vacuolization. We conclude that the reported findings do not represent a specific sign of degeneration and do not constitute a significant morphological marker of disease.