Background: The aim of the study was to analyze family incidence of clefts and to follow the relationship between the type of cleft in a child and in its parents as well as between the sex of the child and of the affected parent.
Material/Methods: The study comprised 540 children with cleft lip and/or palate with a positive family history of cleft. One hundred twenty-seven children were selected from this group whose mother or father had a cleft. In this group, the relationship between the type of cleft and the child’s and affected parent’s sex were analyzed.
Results: Two groups of genetic clefts were confi rmed, each with different risks of repetition: group I with cleft lip and/or palate and group II with isolated cleft palate. It was demonstrated that the type of cleft in a child depends not only on the type of cleft observed in the parent, but that there is also a
great risk of incidence of a cleft in sons of mothers with cleft lip (CL) or cleft lip and palate (CLP) or fathers with cleft lip (CL) and in daughters of mothers or fathers with cleft palate (CP).
Conclusions: 1. In 17% of children with cleft lip and/or palate, a positive family history was found. 2. The cleft type in a child depends not only on the type found in the mother or father, but also on the child’s sex.

Keywords: Child, Cleft Lip - genetics, Cleft Palate - genetics, Family, Pregnancy, Risk Factors