September 8, 2014: Myopathy masquerading as myasthenia
September 8, 2014
Oculopharyngeal muscular dystrophy (OPMD) is a rare, late-onset, autosomal dominant myopathy, characterized by progressive bilateral ptosis and dysphagia. Ophthalmoplegia and proximal limb weakness occur in advanced disease.  OPMD demonstrates complete penetrance by age 70 and is most prevalent amongst Bukhara Jews (1:600). OPMD is caused by a trinucleotide repeat (GCG) within the PABPN1 gene, which dysregulates skeletal muscle metabolism. Unlike some other trinucleotide repeat disorders, this disease does now show anticipation. Diagnosis is confirmed by genetic testing . To date, no cure exists for OPMD. However, blepharoplasty, levator advancement and cricopharyngeal myotomy may be considered for symptom relief.
- Victor M, Hayes R, Adams R. Oculopharyngeal muscular dystrophy. A familial disease of late life characterized by dysphagia and progressive ptosis of the eyelids. N Engl J Med 1962; 267: 1267-1272.
- Brais B. Oculopharyngeal muscular dystrophy: a polyalanine myopathy. Curr Neurol Neurosci Rep 2009; 9: 76-82.
Submitted by Gemma Reynolds BA, (Psych)(Hons) and John Carmody, MRCPI, FRACP, Wollongong Hospital, Wollongong, NSW, Australia.
Disclosures: Dr. Reynolds and Carmody report no disclosures.