Colpocephaly in identical twins.

Colpocephaly is congenital disproportionately enlarged occipital horns of the lateral ventricles. It is easily recognized on computed tomography, magnetic resonance imaging or cerebral ultrasonography. The first report of colpocephaly in identical twins is presented. This is also the first reported instance of above normal intelligence occurring in conjunction with colpocephaly. The associated anomalies found as mirror images in these twins imply a genetic basis for their colpocephaly.