Distal myopathy with vocal cord and pharyngeal weakness belongs to the heterogeneous group of distal myopathies. It has been described in a large American family in which 12 members were affected. Age of onset is after 35 years. Clinical signs include distal weakness, often asymmetrical, of the lower limbs and of the extensor muscles of the fingers. Deltoid muscle weakness is found in 1/4 of patients. Vocal cord and pharyngeal weakness causing a nasal voice and swallowing disorders, are either present at the time of examination or appear later. Ocular muscles are spared. Progression is slow. Risks of inhalation can be reduced with surgery on the vocal cords. Creatine kinase levels are 2-fold higher than normal. The histopathological lesion corresponds to a non-inflammatory myopathy with rimmed vacuoles. It is transmitted as an autosomal dominant trait The causative gene has not yet been identified. It has been mapped to chromosome 5 (5q31). Two muscle genes, myotilin and calsarcan 3, located in the 12 cM linked region of interest, have been sequenced but no mutation has been identified.
Last update: March 2004
- Dr Isabelle PENISSON-BESNIER