(bek´with) Beckwith-Wiedemann syndrome (bek´with ve´dә-mahn) a congenital autosomal dominant syndrome with variable expressivity characterized by exomphalos, macroglossia, and gigantism, often associated with organomegaly , adrenocortical cytomegaly, and dysplasia of the renal medulla. Called also EMG syndrome. and exomphalos-macroglossia-gigantism syndrome.