Three new cases of the congenital syndrome consisting of X-linked lissencephaly, absent corpus callosum, and genital anomalies (XLAG) are reported from the University Hospital, Angers, France. Male sex, intractable epilepsy, hypotonia, and early mortality are additional characteristics. MRI findings include anterior pachygyria, posterior agyria, thickened cerebral cortex, dysplastic basal ganglia, and agenesis of the corpus callosum. Pathologically, the brain shows a trilayered cortex, neuronal migration defect, dysplastic basal ganglia, and gliotic and spongy white matter. Females related to affected boys may be mentally retarded, suffer from epilepsy, and have agenesis of the corpus callosum. 
COMMENT. First described by Berry-Kravis and Israel in 1994, XLAG is characterized by lissencephaly, complete agenesis of the corpus callosum, and hypogenitalism. A posterior agyria, an anterior pachygyria, and an intermediate thickening of the cortex distinguish this syndrome from lissencephaly type I, in which the cortex is thicker, and the corpus callosum may be hypoplastic but not absent. The MRI and neuropathological features are also distinct. Abnormal MRI findings in carrier females also expand the XLAG phenotype.