Van der Woude syndrome in twins.

This article discusses monozygotic twin patients with Van der Woude syndrome, the most common form of syndromic cleft lip and palate, who have concordant manifestations. The syndrome has an autosomal dominant hereditary pattern with variable expressivity and a high degree of penetrance with clinical features, including lower lip sinuses with a cleft lip, cleft palate, or both. Some mutations have been found to cause this disorder. Genetic counseling and informing patients about inheritance is crucial. The appearance, etiology, genetic aspects, differential diagnosis, and treatment modalities are discussed. To the authors' knowledge, this is the third report of monozygotic concordant twins with this syndrome in the literature.