title: Beckwith-Wiedemann syndrome: multiple molecular mechanisms.
abstract: Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth condition with an increased risk of developing embryonic tumours, such as Wilms' tumour. The cardinal features are abdominal wall defects, macroglossia and gigantism. BWS is generally sporadic; only 10-15% of cases are familial. A variety of molecular aberrations have been associated with BWS. The only mutations within a gene are loss-of-function mutations in the CDKN1C gene, which codes for an imprinted cell-cycle regulator. CDKN1C mutations appear to be particularly associated with umbilical abnormalities, but not with increased predisposition to Wilms' tumour. In the remaining BWS subgroups, a disturbance of the tight epigenetic regulation of gene expression (patUPD 11p, microdeletions or epimutations) seems to be the cause of the syndrome. Here we describe the clinical presentation of BWS and its dissociation from phenotypically overlapping overgrowth syndromes. We then review the current concepts of causative molecular genetic and epigenetic mechanisms, and discuss future directions of research.
authors.affiliation: Section of Medical Genetics and Molecular Medicine, Children's Hospital, Johannes-Gutenberg University of Mainz, 55101 Mainz, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Enklaar
authors.forename: Bernhard U
authors.initials: BU
authors.lastname: Zabel
authors.forename: Dirk
authors.initials: D
authors.lastname: Prawitt
mesh_terms: D000818:Animals; D001506:Beckwith-Wiedemann Syndrome / Q000175:diagnosis* / Q000235:genetics*; D050761:Cyclin-Dependent Kinase Inhibitor p57 / Q000235:genetics; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D018392:Genomic Imprinting; D005838:Genotype; D006801:Humans; D008954:Models, Biological; D008957:Models, Genetic; D009154:Mutation; D010641:Phenotype; D014158:Transcription, Genetic
chemical_list: C493964:CDKN1C protein, human; D050761:Cyclin-Dependent Kinase Inhibitor p57