[Movement disorders in Rett syndrome].

INTRODUCTION: Rett syndrome is a progressive neurodevelopmental disorder with onset in early childhood occurring almost exclusively in females and caused by mutations in methyl-CpG- binding protein 2 (MECp2) and is one of the most frequent causes of mental retardation in females. Regression is a defining feature of Rett syndrome and during the regression period the patients develop autistic behaviour. This is the reason why Rett syndrome has been classified as a pervasive developmental autistic spectrum disorder. However movement disorders are so exuberant, characteristic and unique in Rett syndrome that is very difficult to an experienced clinician mistake both situations.

DEVELOPMENT: We can define Rett syndrome as a condition which manifests in the majority of the cases as a hyperkinetic movement disorder and progresses (at varying rates) to a bradykinetic disorder. The aim of this publication is to characterize and describe movement disorders in Rett syndrome based on a revision of the literature and the personal experience of the author.