title: MECP2 mutant allele in a boy with Rett syndrome and his unaffected heterozygous mother.
abstract: Rett syndrome is a severe neurodevelopmental disorder affecting principally females and characterized by a normal postnatal development followed by stagnation and regression of acquired skills. We report a 4-year-old boy with a Rett syndrome phenotype and his unaffected mother both carrying a 44 bp truncating deletion mutation (c.1158del44 or p.388X) in the MECP2 gene. The presence of a skewed X inactivation in the mother provides a possible explanation for the absence of penetrance. The finding of a MECP2 mutation in an unaffected female complicates genetic counseling and further confirms that it is essential to look for mutations in the mothers of all patients with MECP2 mutations.
authors.affiliation: Service of Medical Genetics and Neuropediatric Unit, Geneva University Hospitals, 1 rue Michel-Servet 1211, Geneva Switzerland. alexandre.dayer@medecine.unige.ch
authors.forename: Alexandre G
authors.initials: AG
authors.lastname: Dayer
authors.forename: Armand
authors.initials: A
authors.lastname: Bottani
authors.forename: Isabelle
authors.initials: I
authors.lastname: Bouchardy
authors.forename: Joel
authors.initials: J
authors.lastname: Fluss
authors.forename: Stylianos E
authors.initials: SE
authors.lastname: Antonarakis
authors.forename: Charles-Antoine
authors.initials: CA
authors.lastname: Haenggeli
authors.forename: Michael A
authors.initials: MA
authors.lastname: Morris
mesh_terms: D000328:Adult; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005260:Female; D017353:Gene Deletion; D005787:Gene Frequency / Q000235:genetics; D040181:Genetic Diseases, X-Linked / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing; D006579:Heterozygote; D006801:Humans; D040582:Inheritance Patterns / Q000235:genetics*; D008297:Male; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics*; D009035:Mothers; D009154:Mutation / Q000235:genetics*; D019683:Penetrance; D010641:Phenotype; D015518:Rett Syndrome / Q000175:diagnosis / Q000235:genetics*; D049951:X Chromosome Inactivation / Q000235:genetics
chemical_list: C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2