• This review of the Apert syndrome, based on our research experience with 136 cases, provides a clinically relevant pediatric perspective. The brain is megalencephalic, resulting in a disporportionately high cranium and a mean birth length and weight above the 50th percentile. The growth pattern in childhood consists of a slowing of linear growth so that most values fall between the 5th and 50th percentiles. From adolescence to adulthood, slowing becomes more pronounced. Central nervous system abnormalities may occur in some cases, including malformations of the corpus callosum and limbic structures, gyral abnormalities, hypoplastic white matter, and heterotopic gray matter. Distortion ventriculomegaly is found because of the large brain in a misshapen skull. Progressive hydrocephalus is uncommon. Intelligence in patients with the Apert syndrome varies from normality to mental deficiency. Early release of the coronal suture and advancement and reshaping of the frontal bone reduce further dysmorphic and unwanted growth changes in the skull, but probably do not affect mentation. Associated cardiovascular and genitourinary anomalies occur in 10% and 9.6% of cases, respectively. Other important findings reviewed include upper- and lower-airway compromise, calvarial development, cervical vertebral anomalies, limb defects, ocular and otologic manifestations, and dermatologic characteristics.