Objective: To investigate the etiopathogenesis of isolated Robin sequence.
Design: A longitudinal and prospective study of children with isolated Robin sequence and no other associated syndromes or malformations.
Setting: The study was carried out at the Hospital de Reabilitação de Anomalias Craniofaciais (formerly the Hospital for Research and Rehabilitation of Cleft Lip/Palate), University of São Paulo, Bauru, SP, Brazil, which provides care for patients with lip/palate lesions throughout Brazil.
Patients: Forty-three children were initially included in the study, seven of whom were later found to be cases of Stickler syndrome and excluded. The remaining 36 children presenting only the anomaly triad of microretrognathia, glossoptosis, and cleft palate were followed up from the first month of life to 4 years of age with repetitive clinical and ophthalmological examination.
Main outcome measure: A family history of cleft lip/palate was determined on the basis of information provided by the parents and, when possible, the affected relative was submitted to physical examination.
Results: A family history of cleft lip/palate was observed in 27.7% of cases, one case having a younger brother with only cleft palate but no microretrognathia or glossoptosis. Six cases of isolated cleft palate and three cases of cleft lip with or without cleft palate were present in distant relatives. Complete U-shaped cleft palate (wide cleft) was the most frequent type of cleft, which was present in 75% of cases. Only one case of incomplete cleft palate was observed, but U-shaped; 25% of the patients presented complete V-shaped cleft palate.
Conclusions: We conclude that heredity could be a factor in the etiopathogenesis of isolated Robin sequence and suggest that cleft palate (usually complete and U-shaped) is the primary event in the determination of the triad of anomalies.