Familial spastic paraplegia, peroneal neuropathy, and crural hypopigmentation: a new neurocutaneous syndrome.

A neurocutaneous syndrome is described in which spastic paraplegia, peroneal neuropathy, and crural hypopigmentation are inherited in a dominant pattern. Spastic paraplegia becomes clinically apparent during adolescence or in childhood and progresses slowly throughout the adult years with a variability in severity of expression. Peroneal neuropathy is documented clinically and by slowing on nerve conduction studies. Pattern-reversal visual evoked potentials also yield a delayed response, but brainstem auditory evoked potentials and somatosensory evoked potentials in upper and lower extremities are normal. Crural hypopigmentation is present in each neurologically affected family member. Although the pattern may vary, a pretibial distribution predominates. The lower-extremity abnormalities of the central and peripheral nervous system and neural crest cell derivatives may share a common relationship, but the abnormal visual evoked potentials suggest a more generalized involvement. This family may represent a transition form between familial spastic paraplegia and the spinocerebellar degenerations.