title: Rett syndrome with and without detected MECP2 mutations: an attempt to redefine phenotypes.
abstract: BACKGROUND
  The diagnosis of Rett syndrome (RTT) is based on a set of clinical criteria, irrespective of mutation status. The aims of this study were (1) to define the clinical differences existing between patients with Rett syndrome with (Group I) and without a MECP2 mutation (Group II), and (2) to characterize the phenotypes associated with the more common MECP2 mutations.
  
  
  METHODS
  We analyzed 87 patients fulfilling the clinical criteria for RTT. All were observed and videotaped by the same paediatric neurologist. Seven common mutations were considered separately, and associated clinical features analysed.
  
  
  RESULTS
  Comparing Group I and II, we found differences concerning psychomotor development prior to onset, acquisition of propositive manipulation and language, and evolving autistic traits. Based on age at observation, we found differences in eye pointing, microcephaly, growth, number of stereotypies, rigidity, ataxia and ataxic-rigid gait, and severity score. Patients with truncating differed from those with missense mutations regarding acquisition of propositive words and independent gait, before the beginning of the disease, and microcephaly, growth, foot length, dystonia, rigidity and severity score, at the time of observation. Patients with the R168X mutation had a more severe phenotype, whereas those with R133C showed a less severe one. Patients with R294X had a hyperactive behaviour, and those with T158M seemed to be particularly ataxic and rigid.
  
  
  CONCLUSIONS
  A clear regressive period (with loss of prehension and language, deceleration of growth) and the presence of more than three different stereotypies, rigidity and ataxic-rigid gait seemed to be very helpful in differentiating Group I from Group II.
authors.affiliation: Unidade de Neuropediatria, Serviço de Pediatria, Hospital Geral de Santo António, Porto, Portugal. teresatemudo@hotmail.com
authors.forename: Teresa
authors.initials: T
authors.lastname: Temudo
authors.forename: Mónica
authors.initials: M
authors.lastname: Santos
authors.forename: Elisabete
authors.initials: E
authors.lastname: Ramos
authors.forename: Karin
authors.initials: K
authors.lastname: Dias
authors.forename: José Pedro
authors.initials: JP
authors.lastname: Vieira
authors.forename: Ana
authors.initials: A
authors.lastname: Moreira
authors.forename: Eulália
authors.initials: E
authors.lastname: Calado
authors.forename: Inês
authors.initials: I
authors.lastname: Carrilho
authors.forename: Guiomar
authors.initials: G
authors.lastname: Oliveira
authors.forename: António
authors.initials: A
authors.lastname: Levy
authors.forename: Clara
authors.initials: C
authors.lastname: Barbot
authors.forename: Maria
authors.initials: M
authors.lastname: Fonseca
authors.forename: Alexandra
authors.initials: A
authors.lastname: Cabral
authors.forename: Pedro
authors.initials: P
authors.lastname: Cabral
authors.forename: José
authors.initials: J
authors.lastname: Monteiro
authors.forename: Luís
authors.initials: L
authors.lastname: Borges
authors.forename: Roseli
authors.initials: R
authors.lastname: Gomes
authors.forename: Graça
authors.initials: G
authors.lastname: Mira
authors.forename: Susana Aires
authors.initials: SA
authors.lastname: Pereira
authors.forename: Manuela
authors.initials: M
authors.lastname: Santos
authors.forename: Anabela
authors.initials: A
authors.lastname: Fernandes
authors.forename: Jorg T
authors.initials: JT
authors.lastname: Epplen
authors.forename: Jorge
authors.initials: J
authors.lastname: Sequeiros
authors.forename: Patrícia
authors.initials: P
authors.lastname: Maciel
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D006801:Humans; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics*; D009154:Mutation; D010641:Phenotype; D015518:Rett Syndrome / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology
chemical_list: D051783:Methyl-CpG-Binding Protein 2