Prenatal diagnosis of tuberous sclerosis with intracerebral signs at 14 weeks' gestation

We report the ultrasound detection of cranial abnormalities at 14 weeks' ge station in a fetus subsequently confirmed as having tuberous sclerosis usin g DNA linkage analysis within the affected family. The presence of asymmetr ical ventricular enlargement persisted antenatally. Magnetic resonance imag ing at 26 weeks indicated the possibility of poor gyral formation consisten t with a neuronal migration disorder. Cardiac rhabdomyomata were not visual ized on ultrasound scan until 30 weeks' gestation. Postnatal cranial ultras ound confirmed the significant neuropathology which was manifested by sever e developmental delay and intractable fits in the child. The potential bene fits of earlier diagnosis of tuberous sclerosis by cranial imaging are disc ussed, although in this patient the routine booking scan resulted in a path of prenatal diagnosis being undertaken which had originally been declined. A mechanism is proposed to explain the variable expression of tuberous scl erosis within this family based on altered TSC2 activity affecting neuronal migration. Copyright (C) 1999 John Wiley & Sons, Ltd.