title: Refining the phenotype associated with MEF2C point mutations.
abstract: Up to now, only five-point mutations in the MEF2C gene have been described in patients with severe mental retardation with absent speech, limited walking abilities, epilepsy, and lack of gross malformations. In brain, MEF2C is essential for early neurogenesis, neuronal migration, and differentiation. Here, we present a new patient with severe mental retardation, epilepsy, and hand stereotypies associated with a novel MEF2C frameshift mutation c.457delA. The purpose of this work was to clarify criteria for the selection of patients with severe intellectual disability to screen for deficiency in the MEF2C gene. By combining the clinical data of all patients with MEF2C point mutations published so far with the phenotype of our patient, a targeted search for MEF2C mutations could be applied to patients with a severe intellectual deficiency associated with absence of language and hypotonia, strabismus, and epilepsy (started after 6 months, often well controlled by valproate).
authors.affiliation: CNRS UMR 8104, Institut Cochin, Laboratoire de Génétique des Maladies Neurodéveloppementales, Université Paris Descartes, Paris, France. thierry.bienvenu@inserm.fr
authors.forename: Thierry
authors.initials: T
authors.lastname: Bienvenu
authors.forename: Bertrand
authors.initials: B
authors.lastname: Diebold
authors.forename: Jamel
authors.initials: J
authors.lastname: Chelly
authors.forename: Bertrand
authors.initials: B
authors.lastname: Isidor
mesh_terms: D000293:Adolescent; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D002658:Developmental Disabilities / Q000150:complications / Q000453:epidemiology / Q000235:genetics; D004827:Epilepsy / Q000150:complications / Q000453:epidemiology / Q000235:genetics; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D008607:Intellectual Disability / Q000150:complications / Q000453:epidemiology / Q000235:genetics*; D026161:MADS Domain Proteins / Q000235:genetics*; D064326:MEF2 Transcription Factors; D008297:Male; D008969:Molecular Sequence Data; D018006:Myogenic Regulatory Factors / Q000235:genetics*; D010641:Phenotype; D017354:Point Mutation; D013285:Strabismus / Q000150:complications / Q000453:epidemiology / Q000235:genetics
chemical_list: D026161:MADS Domain Proteins; D064326:MEF2 Transcription Factors; C578040:MEF2C protein, human; D018006:Myogenic Regulatory Factors