[Variable expression of lower lip fistulas in Van der Woude syndrome]

Eight families with the combination of cleft lip and/or cleft palate plus lower lip pits including their microforms were examined with the aim of characterization of microsymptoms. Hypodontia as a further symptom was also taken into consideration. Each of the symptoms was also noted separately in relatives of the patients and are to be considered as a genetic equivalent of the complete form of the autosomal-dominant inherited Van der Woude's syndrome. Knowledge of the variable expression of the basic gene is crucial for risk assessment in family counselling and also for distinguishing from clefts of other genesis with lower recurrence risk.