Various craniofacial abnormalities (CFA) result from maldevelopment of the 1st and 2nd visceral arches, which form the facial bones and ears during the 2nd month of gestation. Causes include several thousand genetic syndromes as well as prenatal environmental factors (eg, use of vitamin A, valproic acid).
Each of the specific congenital anomalies discussed here typically can be associated with many different genetic syndromes, some of which are named (eg, Treacher Collins syndrome). Because of the large number of syndromes, the discussions focus on the different structural manifestations. Detailed information on many of the specific syndromes is available from the Online Mendelian Inheritance in Man® (OMIM®) catalog of genetic disorders.
Some of the anomalies discussed here include
In general, children with CFA should be evaluated for other associated physical anomalies and developmental delays that may require treatment and/or help identify specific syndromes and causes. Identification of the underlying syndrome is important for prognosis and family counseling; a clinical geneticist, when available, can help guide the evaluation.