Molecular analysis of MECP2 gene in Egyptian patients with Rett syndrome

Abstract

Rett syndrome (RTT) is a progressive neurodevelopmental disorder that affects mainly females comprising one of the most common causes of mental retardation in females. Mutations in the X-linked MECP2 gene have been identified to be the major cause for RTT. This study represents one of the limited MECP2 molecular analyses done on Egyptian patients with RTT, in which direct sequencing of MECP2 coding region in 10 female Egyptian patients provisionally diagnosed to have RTT was carried out. Four different pathogenic mutations were identified in four patients; three missense (C380T, C397T and C916T) and one nonsense (C382T). The four mutations, C → T transitions, were located in exon four. Patients with MECP2 mutation showed the clinical course of typical RTT. Analysis of X chromosome inactivation (XCI) pattern of genomic DNA in patients proved to be positive for MECP2 mutations identifying one patient with skewed inactivation pattern.

Keywords: Rett syndrome (RTT); MECP2; Missense; Nonsense; XCI