Varying occurrence of vocal cord paralysis in a family with autosomal dominant hereditary motor and sensory neuropathy

A white British family with the axonal form of hereditary motor and sensory neuropathy (HMSN, type II) contained one member who developed a recurrent laryngeal nerve palsy at the age of 41 years, in addition to 4 years of sym ptomatic polyneuropathy and an abducens nerve palsy. Neither of the other f amily members (the mother and sister) with electrophysiologically confirmed polyneuropathy had any neuropathic symptoms in the limbs or laryngeal or r espiratory muscle involvement. An autosomal dominant pattern of inheritance is likely. This is a second report of this rare form of HMSN (type IIC) in which there is associated laryngeal or respiratory muscle weakness. This f amily differs from the two previously reported pedigrees in which laryngeal or diaphragm weakness had commenced within the first two decades. The disc overy of asymptomatic family members attests to the diagnostic value of cli nical and electrophysiological study of first-degree relatives when larynge al or bulbar symptoms develop in the context of chronic axonal polyneuropat hy. HMSN type IIC should be distinguished from the more common forms of HMS N - type IIA, in which axonal polyneuropathy is restricted to the limbs, an d type IIB, which is of early onset and associated with foot ulceration.