Richieri-Costa-Pereira syndrome: a unique acrofacial dysostosis type. An overview of the Brazilian cases.

We reported on 16 new Brazilian patients and review findings in 12 previously reported cases (25 apparently unrelated Brazilian families) from Hospital of Rehabilitation of Craniofacial Anomalies, presenting with Richieri-Costa-Pereira syndrome. All patients display a unique pattern of anomalies consisting of microstomia, micrognathia, abnormal fusion of mandible, cleft palate/Robin sequence, absence of central lower incisors, minor ears anomalies, hypoplastic first ray, abnormal tibiae, hypoplastic halluces, and clubfeet. Learning disability was also a common finding. The sex-ratio showed deviation toward to female (1.8F:1M). Recurrence in sibs was observed in nine instances and consanguinity in 11, supporting the hypothesis of autosomal recessive inheritance. Nineteen of the 25 families lived in São Paulo State, seven of them (10 affected individuals) from an isolated region named "Vale do Ribeira." The geographic barrier of this region associated with the high incidence of the consanguineous matting suggested that this condition is caused by a rare mutation with a founder effect. With the exception of one patient in France, all known cases are of Brazilian origin. The causative gene of this rare syndrome remains unknown.