Beckwith–Wiedemann Spectrum

Abstract

The Beckwith–Wiedemann spectrum (BWSp) is a human imprinting disorder resulting from aberrant expression or function of imprinted genes from the chromosome 11p15 imprinted gene cluster. BWSp demonstrates wide phenotypic variability and heterogeneous molecular abnormalities (most commonly epimutations at an imprinting centre). Clinical features include macroglossia, anterior abdominal wall defects (including exomphalos), pre and/or postnatal overgrowth, neonatal hypoglycemia, lateralised overgrowth (hemihypertrophy) and predisposition to embryonal tumors (most commonly Wilms tumor). Isolated lateralised overgrowth with a chromosome 11p15 molecular abnormality is part of the BWSp. Delineation of different molecular subgroups of BWSp has identified epigenotype–phenotype correlations for exomphalos, lateralised overgrowth and embryonal tumor risks. This article reviews clinical and molecular aspects of BWSp drawing on the recommendations of a recent International Consensus Statement.