Clinical and genetic study on 356 Brazilian patients with a distinct phenotype of cleft lip and palate without alveolar ridge involvement.

Oral clefts include cleft lip (CL), cleft lip with cleft palate (CLP) and cleft palate (CP), with wide variations in clinical presentation and degree of severity. We described a sample of individuals with CL and CP without alveolar arch involvement (CL + CP) to verify if the characteristics of this group are distinct from those with CL with or without CP (CL/P) described in literature. The sample was composed of 356 patients with CL + CP, registered at HRCA-USP, Bauru-SP-Brazil. The following characteristics were investigated: sex ratio, parental age at the time of conception, parental consanguinity, familial recurrence, laterality of the cleft and associated anomalies. A subgroup of 30 individuals with microforms of CL and CP were taken from the sample and compared with the remaining cases. Statistical differences were found between this CL + CP sample and the literature data for groups with CL/P regarding laterality, sex ratio, consanguinity, familial recurrence, and the presence of associated anomalies. The microform sample showed a statistical difference in paternal age. In most evaluated aspects, this sample presents similar characteristics to the consulted literature data for CL/P; as do the group of microform cleft cases when compared with the remaining CL + CP sample in this study. Microforms of cleft can represent a target group for investigation into the embryogenetic mechanisms of oral clefts and their phenotypic variability.