Editor—Hereditary distal limb weakness and atrophy is a heterogeneous condition that may be neurogenic or myopathic in origin. Hereditary motor and sensory neuropathy (HMSN) I and II (also known as Charcot-Marie-Tooth (CMT) 1 and 2), distal spinal muscular atrophy (dSMA), and the distal myopathies may all present with this clinical picture. Traditionally, these disorders were differentiated according to electrophysiological and histopathological characteristics, with subtypes of each group identified on the basis of inheritance pattern, age of onset, and associated clinical features. The localisation of several genes that confer susceptibility to these disorders has necessitated the re-evaluation of current classification systems, as conditions that were clinically classified as distinct are now known to be allelic at the genetic level.

Vocal cord weakness/paralysis is occasionally associated with distal muscular atrophy. This association was first described by Young and Harper1 in a Welsh family in which the disorder segregated in an autosomal dominant fashion. The presentation was one of progressive distal muscle wasting and weakness together with a dysphonic or hoarse voice. Motor and sensory nerve conduction was normal with the exception of one patient who showed mild motor slowing. Spontaneous fibrillation was detected on EMG. Unilateral or bilateral vocal cord palsy was present in all affected subjects. The findings were consistent with anterior horn cell disease and the condition was assumed to be a form of dSMA associated with vocal cord paralysis. In a subsequent classification of the proximal and distal spinal muscular atrophies the disorder was designated dSMA type VII.2

Recently, a family with vocal cord and pharyngeal weakness associated with a distal myopathy was reported.3 This family has …