title: Rett syndrome: revised diagnostic criteria and nomenclature.
abstract: OBJECTIVE
  Rett syndrome (RTT) is a severe neurodevelopmental disease that affects approximately 1 in 10,000 live female births and is often caused by mutations in Methyl-CpG-binding protein 2 (MECP2). Despite distinct clinical features, the accumulation of clinical and molecular information in recent years has generated considerable confusion regarding the diagnosis of RTT. The purpose of this work was to revise and clarify 2002 consensus criteria for the diagnosis of RTT in anticipation of treatment trials.
  
  
  METHODS
  RettSearch members, representing the majority of the international clinical RTT specialists, participated in an iterative process to come to a consensus on a revised and simplified clinical diagnostic criteria for RTT.
  
  
  RESULTS
  The clinical criteria required for the diagnosis of classic and atypical RTT were clarified and simplified. Guidelines for the diagnosis and molecular evaluation of specific variant forms of RTT were developed.
  
  
  CONCLUSIONS
  These revised criteria provide clarity regarding the key features required for the diagnosis of RTT and reinforce the concept that RTT is a clinical diagnosis based on distinct clinical criteria, independent of molecular findings. We recommend that these criteria and guidelines be utilized in any proposed clinical research.
authors.affiliation: Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA. jneul@bcm.tmc.edu
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Neul
authors.forename: Walter E
authors.initials: WE
authors.lastname: Kaufmann
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Glaze
authors.forename: John
authors.initials: J
authors.lastname: Christodoulou
authors.forename: Angus J
authors.initials: AJ
authors.lastname: Clarke
authors.forename: Nadia
authors.initials: N
authors.lastname: Bahi-Buisson
authors.forename: Helen
authors.initials: H
authors.lastname: Leonard
authors.forename: Mark E S
authors.initials: ME
authors.lastname: Bailey
authors.forename: N Carolyn
authors.initials: NC
authors.lastname: Schanen
authors.forename: Michele
authors.initials: M
authors.lastname: Zappella
authors.forename: Alessandra
authors.initials: A
authors.lastname: Renieri
authors.forename: Peter
authors.initials: P
authors.lastname: Huppke
authors.forename: Alan K
authors.initials: AK
authors.lastname: Percy
mesh_terms: D000818:Animals; D006801:Humans; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D015518:Rett Syndrome / Q000175:diagnosis* / Q000235:genetics*; D009626:Terminology as Topic
chemical_list: D051783:Methyl-CpG-Binding Protein 2