prenatal diagnosis of apert syndrome without craniosynostosis - case report diagnóstico pré-natal do síndrome de apert sem craniossinostose - caso clínico

Apert syndrome is a rare genetic disorder characterized by craniosynostosis, midfacial hypoplasia and severe symmetrical syndactyly (cutaneous and bony fusion) of the hands and feet. Despite being inherited in an a utosomal dominant manner, most cases are sporadic, the resul t of a de novo mutation. The prevalence of this con dition at birth is estimated as 15.5 per million (1:65 000). We report the prenatal diagnosis of Apert syndrome associated with increased nuchal translucency and with no ultr asonographic indings of craniosynostosis. An obstetrical ultrasound performed at 20 weeks of gestation showed ocular hypertelorism and bilateral syndactyly of th e hands. Examination of the remaining fetal structures revealed no further fetal anomalies, in particular no premature fusion of the cranial sutures. Genetic evaluation revealed a S252W mutation in ibroblast growth factor receptor 2, consistent with Apert syndrome. Fetal autopsy performed at 24 weeks showed a male fetus with symmetric syndactyly of both hands and feet; the skull showed a mild frontal bossing, ocular hypertelorism, depressed nasal bridge and conirmed the absence of premature fusion of the cranial sutures. Prenatal diagnosis of Apert syndrome in sporadic cases can be dificult because the characteristic changes in cranial and orbital shape related to craniosynostosis may not be present until the third-trimester. Syndactyly and abnormalities of the skull shape should lead to the suspicion of Apert syndrome even in the absence of craniosynostosis. This case also suggests that increased nuchal translucency may be associated with this syndrome.