title: Molecular screening of MECP2 gene in a cohort of Lebanese patients suspected with Rett syndrome: report on a mild case with a novel indel mutation.
abstract: BACKGROUND
  Rett syndrome (RTT), an X-linked, dominant, neurodevelopment disorder represents 10% of female subjects with profound intellectual disability. Mutations in the MECP2 gene are responsible for up to 95% of the classical RTT cases, and nearly 500 different mutations distributed throughout the gene have been reported.
  
  
  METHODS
  We report here the molecular study of two isoforms, MECP2_e1 and MECP2_e2, in 45 Lebanese girls presenting developmental delay and at least one of the following features: microcephaly, neurodegeneration, abnormal behaviour, stereotypical hand movements, teeth grinding and difficulty in walking. Mutation screening was performed by denaturating high-performance liquid chromatography combined with direct sequencing.
  
  
  RESULTS
  Sixteen variants were noted, of which 14 have been previously reported: five suspected polymorphisms and nine mutations. Two variants were novel mutations in exon 4: c.1093_1095delGAG (p.E365del) and c.1164_1184delACCTCCACCTGAGCCCGAGAGinsCTGAGCCCCAGGACTTGAGCA (p.P388PfsX389). The deletion was found in an 8-year-old girl with typical clinical features of RTT. The indel was found in a 6-year-old girl with a very mild phenotype.
  
  
  CONCLUSIONS
  Genotype/phenotype correlation is discussed and the importance of a molecular study of MECP2 gene in patients with very mild features or a regression after the age of 2 is raised.
authors.affiliation: Unité de Génétique Médicale et laboratoire associé INSERM à l'Unité UMR_S910, Université Saint-Joseph, Beirut, Lebanon.
authors.forename: S
authors.initials: S
authors.lastname: Corbani
authors.forename: E
authors.initials: E
authors.lastname: Chouery
authors.forename: J
authors.initials: J
authors.lastname: Fayyad
authors.forename: A
authors.initials: A
authors.lastname: Fawaz
authors.forename: O
authors.initials: O
authors.lastname: El Tourjuman
authors.forename: C
authors.initials: C
authors.lastname: Badens
authors.forename: C
authors.initials: C
authors.lastname: Lacoste
authors.forename: V
authors.initials: V
authors.lastname: Delague
authors.forename: A
authors.initials: A
authors.lastname: Megarbane
mesh_terms: D000293:Adolescent; D000483:Alleles; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D005091:Exons / Q000235:genetics; D005260:Female; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D054643:INDEL Mutation / Q000235:genetics*; D008607:Intellectual Disability / Q000175:diagnosis / Q000235:genetics; D007861:Lebanon; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics; D015518:Rett Syndrome / Q000175:diagnosis / Q000235:genetics*
chemical_list: C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2