Etiopathogenesis of isolated Robin sequence

Objective: To investigate the etiopathogenesis of isolated Robin sequence, Design: A longitudinal and prospective study of children with isolated Robi n sequence and no other associated syndromes or malformations, Setting: The study was carried out at the Hospital de Reabilitacao de Anoma lias Craniofaciais (formerly the Hospital for Research and Rehabilitation o f Cleft Lip/Palate), University of Sao Paulo, Bauru, SP, Brazil, which prov ides 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 microretrognath ia, glossoptosis, and cleft palate were followed up from the first month of life to 4 years of age with repetitive clinical and ophthalmological exami nation. Main Outcome Measure: A family history of cleft lip/palate was determined o n 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 case s, one case having a younger brother with only cleft palate but no microret rognathia or glossoptosis. Six cases of isolated cleft palate and three cas es of cleft lip with or without cleft palate were present in distant relati ves. 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 c left palate was observed, but U-shaped; 25% of the patients presented compl ete V-shaped cleft palate, Conclusions: We conclude that heredity could be a factor in the etiopathoge nesis of isolated Robin sequence and suggest that cleft palate (usually com plete and U-shaped) is the primary event in the determination of the triad of anomalies.