title: Phenotypic variability in two infants sharing the same MECP2 mutation: evidence of chromosomal rearrangements and high sister-chromatid exchange levels in Rett syndrome.
abstract: Rett syndrome (RTT) whose major cause is the mutations in the X-linked MECP2 gene is a genetic disease that affects females. We screened two RTT patients using cytogenetic studies and in silico analysis as well as molecular analysis by the direct sequencing of MECP2. The cytogenetic results showed that although patient A was karyotypically normal, patient B showed chromosomal abnormalities, including chromosomal breakage in both chromosomes 2 and 5. In addition, chromosome 9 was detected on heteromorphic pattern (9ph+). A significant increase in sister-chromatid exchange (SCE) frequency was also observed in this patient. Although both patients were karyotypically different, they share the same MeCP2 mutation (p.P152R) which was predicted to be deleterious. To our knowledge, we describe the first association between MECP2 mutation, chromosomal abnormalities and high SCE frequency, which further validates the importance of the thorough chromosomal and molecular analyses that should be performed on the suspected RTT cases.
authors.affiliation: Laboratory of Human Molecular Genetics, Faculty of Medicine, University of Sfax, Avenue Magida Boulila, 3029, Sfax, Tunisia. marwa.kharrat.feki@gmail.com.
authors.forename: Marwa
authors.initials: M
authors.lastname: Kharrat
authors.affiliation: Infant Neurology Department, C.H.U. Hédi Chaker de Sfax, Sfax, Tunisia.
authors.forename: Ines
authors.initials: I
authors.lastname: Hsairi
authors.affiliation: Laboratory of Human Molecular Genetics, Faculty of Medicine, University of Sfax, Avenue Magida Boulila, 3029, Sfax, Tunisia.
authors.forename: Hajer
authors.initials: H
authors.lastname: Doukali
authors.affiliation: Laboratory of Human Molecular Genetics, Faculty of Medicine, University of Sfax, Avenue Magida Boulila, 3029, Sfax, Tunisia.
authors.forename: Nourhene
authors.initials: N
authors.lastname: Fendri-Kriaa
authors.affiliation: Laboratory of Human Molecular Genetics, Faculty of Medicine, University of Sfax, Avenue Magida Boulila, 3029, Sfax, Tunisia.
authors.forename: Hassen
authors.initials: H
authors.lastname: Kammoun
authors.affiliation: Laboratory of Human Molecular Genetics, Faculty of Medicine, University of Sfax, Avenue Magida Boulila, 3029, Sfax, Tunisia.
authors.forename: Leila
authors.initials: L
authors.lastname: Ammar-Keskes
authors.affiliation: Infant Neurology Department, C.H.U. Hédi Chaker de Sfax, Sfax, Tunisia.
authors.forename: Chahnez
authors.initials: C
authors.lastname: Triki
authors.affiliation: Laboratory of Human Molecular Genetics, Faculty of Medicine, University of Sfax, Avenue Magida Boulila, 3029, Sfax, Tunisia. faiza.fakhfakh02@gmail.com.|Department of Life Sciences, Faculty of Science of Sfax, University of Sfax, Sfax, Tunisia. faiza.fakhfakh02@gmail.com.
authors.forename: Faiza
authors.initials: F
authors.lastname: Fakhfakh
mesh_terms: D002648:Child; D002675:Child, Preschool; D020732:Cytogenetic Analysis; D005260:Female; D015321:Gene Rearrangement / Q000235:genetics*; D005838:Genotype; D006801:Humans; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics*; D010641:Phenotype; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D015518:Rett Syndrome / Q000235:genetics*; D012854:Sister Chromatid Exchange / Q000235:genetics*; D014416:Tunisia
chemical_list: C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2
keywords: Chromosome rearrangements; MECP2 gene; Rett syndrome; SCE; p.P152R