Fetal alcohol syndrome: Changes in craniofacial form with age, cognition, and timing of ethanol exposure in the macaque

One component of the fetal alcohol syndrome (FAS) facial phenotype is a fro ntonasal anomaly characterized by a thin upper lip and a smooth philtrum. T he expression of this anomaly can diminish with age and occurs infrequently in prenatal alcohol-exposed individuals. This study sought to explain thes e observations. Standardized craniofacial cephalograms of 18 nonhuman prima tes exposed weekly to ethanol or sucrose solution in utero were measured at ages I, 6, 12, and 24 months to assess skeletal changes in craniofacial fo rm with age, cognition, and timing of ethanol exposure. The data suggest th at there may be a critical period for induction of alcohol-induced craniofa cial alterations that occurs very early in gestation and is very short in d uration (gestational days 19 or 20). The alterations were scarcely detectab le at age 1 month, were most prominent at 6 months, and diminished progress ively at 12 and 24 months in the macaque. The appearance and disappearance of the thin upper lip and smooth philtrum may be, explained by underlying c hanges in skeletal structure with age. The infrequent occurrence of the FAS frontonasal anomaly may be explained, in part, by its short critical perio d of induction. (C) 1999 Wiley-Liss, Inc.