Following maternal chicken pox in the 14th week of pregnancy, a male infant was born with low birth weight, muscle wasting and limb contractures, hypotonia and areflexia. A rising titre of varicella-zoster-specific IgM (by enzyme-linked immunoabsorbent assay) confirmed congenital infection, and electromyogram showed widespread denervation. Death occurred at 8 days. Neuropathological examination revealed destructive and inflammatory lesions of cerebral cortex and white matter, thalamus, brain stem and spinal cord. In addition there were cerebellar heterotopias and bilateral polymicrogryic malformations of the insular cortex.