Van der Woude syndrome: a review. Cardinal signs, epidemiology, associated features, differential diagnosis, expressivity, genetic counselling and treatment

Congenital pits of the lower lip constitute a rare developmental malformation, transmitted by an autosomal dominant mode, with considerable heterogeneity as regards the expression of the disorder. They are present in van der Woude syndrome (VWS), in which clefts of the upper lip and/or palate are often observed. Literature related to the various parameters associated with and relevant to the disorder is extensive. The purpose of this review is to cover, synthesize and categorize the existing knowledge into distinct entities, in order to facilitate understanding of the aetiopathogenesis of the malformation, its clinical manifestations and histological features, the epidemiology of the syndromic situation and the fundamental approach to an integral differential diagnosis. Special emphasis is given to the rationale underlying the treatment modalities that have been suggested, and the necessity for appropriate genetic counselling, as the disorder shows a high affinity with clefts and a familial type of occurrence.