Prenatal mandibulofacial dysostosis (Treacher Collins syndrome).

The clinical, radiographic, and histologic aspects of Mandibulofacial Dysostosis (Treacher Collins Syndrome)--MFD--are described as observed in a human fetus of approximately 15 weeks gestation age. Findings in the present study do not differ significantly from those previously reported, as the abnormal fetus exhibited the peculiar ocular, otic, and mandibular defects common in descriptions of postnatal survivors. Although exhibiting the major signs and symptoms of MFD even at this early developmental stage, previously unreported relationships dealing with the ossification of the mandible and salivary gland hyperplasia are noted. Contrary to expectation, vascularization appears excessive. The pathogenesis of the events leading to the deformities of the first and second branchial arches is extrapolated to seven weeks in utero.