[Electrophysiological study of a family of subjects presenting primary hypertrophic neuritis].

Primary hypertrophic neuritis (hereditary motor and sensory neuropathy types I and III) can easily be characterized in affected families by nerve conduction measurement. Such a study is reported in a family with two affected subjects from two successive generations, a man and one of his daughters (type I). Nerve conduction velocities (NCV) were dramatically low (down to 10 m/sec) in three other subjects from the second generation without any obvious clinical symptom. These cases show again the lack of correlation between electrophysiological data and clinical features in these affections. They emphasize the usefulness of electrophysiological diagnosis among subjects without any obvious clinical sign.