Vincristine neuropathy: neurophysiological and genetic studies in a case of Wilms tumor.

We report a 10-year-old female with Wilms tumor (WT) who developed severe neuropathy after the fifth weekly dose of vincristine. The girl was previously asymptomatic and the family history was negative for inherited neuropathies. Neurophysiological studies and electrodiagnostic findings were suggestive of a axonal neuropathy with greater motor than sensory characteristics not typical of Charcot-Marie-Tooth (CMT) Type 1A. Genetic studies were performed in view of the degree of neurotoxicity. Duplication of 17p11.2 was found that supported the diagnosis of CMT Type 1A. The patient is alive without disease and with minimal weakness of the lower extremities after 42 months. Neurophysiological studies, repeated at 8 and 24 months, were negative. Although the association of asymptomatic CMT and vincristine neuropathy has been previously reported, the present case is of note because the reversible neuropathy occurred after five doses of vincristine, suggesting that possible more people suffering vincristine neurotoxicity may have underlying and asymptomatic CMT. Copyright 2004 Wiley-Liss, Inc.