[Inheritance on commissural lip pits].
The purpose of this study was to investigate and to determine the mode of inheritance in commissural lip pits. Fifteen probands and their family members were clinically examined. Afterwards, the pedigrees of the fifteen families were constructed. The study of these pedigrees showed that: 1) The condition usually appeared in several members and in several generations of the same family. 2) Both sexes were affected almost equally. 3) The affected persons were vertically directed in the pedigrees. 4) The condition was transmitted from fathers and mothers to their daughters or sons or both in thirteen pedigrees. Especially, transmission from fathers to sons, was observed in four pedigrees. These findings suggest that commissural lip pits are a genetic disorder exhibiting autosomal dominant inheritance. 5) Gaps in generation were observed in two pedigrees interpreted as reduced penetrance of the responsible gene. The clinical examinations showed that the depth of the pits some times varied among the affected members of the same family interpreted as variable expressivity of the trait.