Two patients with a congenital neuropathy are described. Both had atypical features including: ichthyosis and a mild anterior chamber cleavage syndrome. Both had severely reduced, or absent, sensation for light touch, vibration, position and temperature. Pain sensation was mildly reduced. There was some evidence of motor involvement but this was relatively minor compared with the sensory involvement. Nerve action potentials were small or absent and sural nerve biopsies showed almost complete absence of myelinated nerve fibres with multiple bundles of abnormally arranged axons and Schwann cell processes. These patients appear to have an undescribed syndrome in which the large sensory neurons and the anterior chamber of the eye did not develop properly. This may reflect a failure of migration, differentiation or proliferation of neural crest cells.