Apert (1906) was the first to identify a syndrome characterized by the association of acrocephaly with syndactyly, acrocephalosyndactylism. Since then Apert syndrome has been recognized as a clinical entity. Although hydrocephalus was rarely reported as an associated malformation, it was suggested that hydrocephalus might be responsible for mental retardation in some cases of Apert syndrome. We report a case of Apert syndrome presenting as fetal hydrocephaly at 28 weeks gestational age, and we review the literature. We suggest that hydrocephalus should be considered as a major associated malformation, and a complete evaluation with sonogram and computed tomography scan is recommended in any newborn suspected of having Apert syndrome after routine cephalometric measurement.

Hydranencephaly is an uncommon congenital brain malformation in which there is complete or almost complete absence of the cerebral hemispheres. The leptomeninges and dura are completely formed and occupy their normal position in the skull.' Antenatal detection of intracranial abnormalities is now available with advanced ultrasound technology and there have been a few reports of hydranencephaly diagnosed in utero by sonography.2-6The present case is, to our knowledge, the first in which hydranencephaly was associated with renal agenesis. This association, and the oligohydramnios resulting from the latter condition, makes the case unusual. Several other coexistent anomalies were also found in this fetus. CASE REPORTThe patient, a 20-year-old woman, gravida 1, para 0, was first seen in our hospital during her 35th menstrual week. Prior to this time, she had received routine prenatal care at another institution. In the first and second trimester of pregnancy, the uterine size corresponded to the estimated gestational age based on the last menstrual period.An ultrasound examination performed at our hospital during the patient's 35th menstrual week revealed marked oligohydramnios and an apparently enlarged fetal head. The cranial vault was predominantly fluid-filled, and only a smallFrom the