TABLE I.

Cases of Likely Monozygotic Twins with Van der Woude Syndrome in the Literature

	Zygosity/ Zygosity Testing	Presentation
Cervenka et al, 1967	Monozygotic/ Zygosity determined by examination of features and blood group	Lip pits in both, CL in one
Hersh and Verdi, 1992	Monozygotic/ DNA linkage analysis	Unilateral CL/P, lip pits and natal tooth in both
Kondo et al., 2002	Monozygotic/ Tested with microsatellite markers	One twin with the condition due to a new mutation, one twin without the mutation
Tokat et al., 2005	Monozygotic/ No information on testing	Lip pits in both, CL in one, CP in one
Vignale et al., 1998	Unknown	Unilateral CL and lip pits in both