Familial lissencephaly with extreme neopallial hypoplasia

Two siblings, male and female, with identical lethal brain malformation are described. Their anomaly is characterized by very low brain weight, lissencephaly, wide ventricles and thin neopallium (colpocephaly) varying in thickness between 0.2 and 3 mm. The neocortex is four layered as in classic lissencephaly. Brainstem and cerebellar anomalies are more extensive than in cases hitherto described in detail. No extracranial malformation is found....