Peripheral nerve abnormalities in the congenital cataracts facial dysmorphism neuropathy (CCFDN) syndrome

Observations have been made on the peripheral nerve changes in four patient s, ranging in age from 4 to 32 years, with the congenital cataracts facial dysmorphism neuropathy syndrome. Myelinated fibre density was within normal limits. The salient abnormality was diffuse hypomyelination which, in the older patients, was associated with demyelination and then axonal degenerat ion. These findings could be correlated with the relative preservation of s ensory action potential amplitude despite markedly reduced nerve conduction velocity. Unmyelinated axon density was preserved. The morphological obser vations suggest the operation of a developmental process affecting myelinat ion with a later superimposed degenerative disorder.